The Monitor FAQ

[menace]

I am going to start to compile information on monitors with MAME. this will include information on arcade monitors as well as PC's.  The format will be mostly question and answer with isolated facts and trivia thrown in so you can impress girls at bars with your elite knowledge (don't try this as you will remain single longer).  Please feel free to contribute information you have that is not posted

BUT LEAVE OPINIONS AND UNCERTAIN FACTS OUT OF IT. 

Theres nothing worse than reading an FAQ and people are having a dispute over whats correct.  if you see an error--PM me and I will correct it in the thread with the correct information  Thanks!.  I have attached a pic showing the parts and their common names.

Q:  What monitor do i need to run mame?
A:  you can use 1 of 3 things,  a PC monitor, a genuine arcade monitor or a television. 

PC monitor:
easiest to use.  plugs into your windows or dos (or Linux ) and automatically selects the best fit for the display you are using depending on the game.  Does not look genuine without the addition of scanlines or other such software since your monitors ultimate resolution is much higher than an arcade monitors.

Arcade Monitor:
At little more tricky to get going but easier with the advent of the ArcadeVGA interface.  Without the ArcadeVGA, games are not all correctly displayed in regular mame and a more advanced version of Mame is required, hence advmame.  With advmame you can configure all the game resolutions manually for best possible fit into the monitor you are using (i.e. fitting vertical game like Pac-Man into horizontal screen). 

More advmame info can be found here: http://advancemame.sourceforge.net/ 
ArcadeVGA info can be found here: www.ultimarc.com
Help configuring your system to run advmame can be found here: http://www.mame.how.to/

Using a television:
I Used an old ATI 4mb PCI rage 128 card with s-video and RCA out.  I plugged in the s-video cable to the tv and configured ATI's settings to recognize the second display.  Then on the next bootup it automatically looked and found the tv and used it is a display device (from bios all the way to windows)--very very easy!  Between the RCA and S-video, the S-video offered a superior display with better colors and a more solid picture.  Windows and mamewah (my frontend) were run at 640x480 and it looked pretty good (arcade monitor still preferred here though )

Q: but which one do I choose?
A:  that depends on your time, level of expertise, comfort with electronics, money etc.  Only you can decide, and some research on your behalf is in order to see which you feel most comfortable with.  Each has their own limitations and difficulties and your specific situation will govern the choice. (too vague? you want someone to think for you? ok--Use an arcade monitor its more authentic and you can brag later how brilliant you are interfacing what is basically a dummed down tv to your pc )

Q:So now you have a monitor, how do you hook it up?
A:  Pc Monitor--plug it in as normal. 
Arcade monitor will need some special interfacing.  On your monitor mainboard (chassis) there will be 6 to 10 pins for input.  These are different depending on your monitor and you will need to identify them before continuing (more on that later) but for arguments sake you already know your monitor and what input is supposed to go where.  These being RED, GREEN, BLUE, GRD, Horizontal+,Vertical+, Horizontal-, Vertical- and sometimes an additional GND. 

Identify these values on your video cable (see here: http://www.ultimarc.com/monfaq.html#monitorcable)  And connect RED to RED, Blue to BLUE etc.  All your grounds can be combined into one and connected to a single ground on the monitor chassis.  With regards to horizontal and vertical sync, this may be monitor dependent to get it to work.  Some require H- and V- from the monitor to be connected to separate H and V lines in your cable and some require them to be connected together. 

You may also be required to power the monitor with an isolation transformer--this means you CANNOT just plug your monitor into a wall socket, you need to isolate it from the incoming ac power.  if you aren't sure whether you need one or not just ask in the monitor forum,but chances are if it came from an older arcade game you will need one.

Fortunately you are likely not the first to own this monitor so there is help available here or in arcade newsgroups.  Just identify your monitor (more on this) and ask how your sync should be connected.  At little research and you should find this information without even asking.

[menace]

continued...

Q: You said you would help me identify my monitor, so identify already...
A:  Ah the impatience of youth...

The best thing to do first is look for a tag or sticker that explicitly says what model you have.  Please note that only manufacturer's and a few gifted arcade guys can identify using serial numbers --please find model numbers (it will say model:_____).  Failing that, look for identifying marks on the boards themselves (chassis and neckboard)  Sometimes there are numbers, sometimes there are letters that can help identify what it is you have. 

Last bet, take as good a top down picture as you can--this may require you to discharge the monitor and remove it from the machine but since it's likely not working anyways you will be doing this regardless (more on this later)

Armed with your picture, visit:
www.jomac.net.au/mon.htm OR

Bob Roberts-big bear bulletin board and see "whats my monitor" about halfway down the page.  Bob's site is excellent for newbies and experience people alike for finding new information and ordering parts --especially cap kits (more on this)  It may take awhile but you should be able to match yours with one there.  If you don't, post it here and someone hopefully can help you.  Your picture should be below 250KB in size and have a resolution of 640x480 (everyone hates uber-large pictures).  You can also email bob and ask if he can help you although the last thing I want is someone to fire off pictures to him without even trying to identify it or without asking him!

Q: So my monitor has X/Y symptoms what do I do?
A:  Cap kit.

If your monitor suffers from odd colors, waviness, dimness, and general surliness the first and foremost thing you should try is installing a cap kit.  These means replacing the vast majority of the electrolytic capacitors (caps) with new ones.  (these are the colored vertical cylinders on your board) As your original caps will heat up and contract over a period of 20 years, eventually they break down and/or leak causing all sorts of headaches to arcade enthusiasts everywhere.  Replacing them is always a good idea.  To do this you need to <gulp> discharge your monitor.

How to discharge a monitor:

See here for pictures and directions: http://www.arcadegames.net/sightsound/discharge.ppt

As this gentlemen points out, it isn't so bad if you pay attention!!!  DO NOT connect your alligator clip to anything other than the chassis of your monitor and the end of your screwdriver.  The ground in your outlet has absolutely nothing to do with your monitor do not ground the anode to anything other than the chassis of the monitor.

Just to hi-lite some points:
1. unplug the monitor from the power source
2. use a long handled screwdriver with a well insulated handle
3. keep the screwdriver side of the alligator clip as close to the end of the screwdriver (away from you)
4. keep one hand in your pocket
5. take off watches or rings and conductive things
6.be mindful of the chassis padawan--if you are touching it you could become the primary circuit path--NOT GOOD
7.  its always a good idea to pause a minute and discharge another time and another before removing the sucker cup (anode cap).

I left this vague so that you will go to the site and read how its done in its entirety.

Now that you have discharged the monitor, desolder the caps and replace with new ones that you ordered from Bob Roberts or elsewhere.  BE VERY OBSERVANT AS TO THE - AND + MARKINGS OF THE CAPS!!  If you get one backwards--poof!  it could also take other components with it.

[menace]

Notes on arcade monitor dimness.

(most) Arcade monitors were meant to operate at around 5V, while most video cards output at 1V.  Therefore in order to increase the brightness of the picture you can either crank up the brightness controls (some suggest this shortens the life of your monitor but I can't confirm this with any hard evidence or experience) or you could try a video amplifier.  Ultimarc (www.ultimarc.com ) makes a ready made one or you could build your own from here: http://www.mameworld.net/pc2jamma/hardware.html  I make no claims as to whether this works but am merely presenting options.

[b3atmania]

A MAME monitor FAQ is a great idea. I hope to write some more tonight.

What is the resolution of my monitor?
Monitors are classified by their horizontal bandwidth and number of visible lines. This effectively describes their resolution. You can roughly estimate their vertical refresh rate (frames per second) by dividing the horizontal bandwidth by the number of visible lines. For a standard resolution monitor this would be 15750 / 240 =~ 65 Hz.

resolution	horizontal bandwidth	# lines	# colors	comparable
standard	15.75 kHz	240	unlimited	CGA or NTSC TV
extended	16.5 kHz	288	unlimited	CGA or PAL TV
medium	25 kHz	380	unlimited	EGA
high	31.5 kHz	450	unlimited	VGA

Note that we are talking about CRT monitors only. If your monitor is advertised as LCD, TFT, plasma or projection it cannot be classified using the table above.

[menace]

(Thanks for contributing b3atmania!)

To test your colors (to determine if you need a capkit or just adjust some pots)  run the "Sente Diagnostic Cartridge" in mame and select test 12--color bars.  Your colors from left to right should be: Black, white, red,green,blue, cyan and magenta.

[menace]

I will post monitor specific info as a come across it but if other members would like to cut and paste specific tidbits about their monitor in here, they are more than welcome (and encouraged ).  Please clearly identify the make and model of the monitor to which the info pertains and credit whoever provided the info


Wells Gardner K4600 daughter board information provided by Ken Layton

Fortunately, all versions of the video interface card are interchangeable between the various versions of the 4600 series monitor.

The lower the "P" number the earlier the version the board is. Here are the versions I know of:

P297 has composite negative sync only. There is only one video input connector. Originally installed on 19K4601. Video input (P205) connector pinout:
1 - Video green
2 - Video blue
3 - No connection
4 - Video red
5 - Ground
6 - Composite negative sync

P298 has separate positive sync only. Originally installed on 19K4603 & 19K4653. Video input (P205) connector pinout:
1 - Video red
2 - Video green
3 - Video blue
4 - Ground
5 - Vertical + sync
6 - Horizontal + sync

P302 has composite negative sync only. Originally installed on 19K4602 and 19K4604. Video input (P205) connector pinout:
1 - Video green
2 - Video blue
3 - No connection
4 - Video red
5 - Ground
6 - Composite negative sync

P306 has positive and negative separate sync. Originally installed on 19K4615. Video input (P205) connector pinout:
1 - Video red
2 - Video green
3 - Video blue
4 - Ground
5 - Vertical + sync
6 - Horizontal + sync

P307 has positive sync. Originally installed on 19K4613. Video input (P205) connector pinout:
1 - Video red
2 - Video green
3 - Video blue
4 - Ground
5 - Vertical + sync
6 - Horizontal + sync


Sync  connector (P204) pinout:
1 - Ground
2 - Vertical - sync
3 - Horizontal - sync

P317 has positive and negative separate sync. This is the latest version and has the desirable "horiz. centering" pot mounted at the edge of the board right where you can easily get to it. The "black level" (a.k.a. brightness) is also mounted next to this pot. Originally installed on 19K4625, 19K4626, and 19K4675. Video input (P205) connector pinout:
1 - Video red
2 - Video green
3 - Video blue
4 - Ground
5 - Vertical + sync
6 - Horizontal + sync

Sync connector (P204) pinout:
1 - Ground
2 - Vertical - sync
3 - Horizontal - sync

Edit:

Oh, hold the fort----I just found one of my Wells manuals and found the P302 schematic. Wells-Gardner manual number 69X0942-100 dated 9-80 has the info for this board in it. This is the manual for the 4601, 4602,4603,4604, and 4653.

I think this board was used on Galaxian games originally.

[menace]

Wells Gardner K7191 chassis numbers

if there is a P447 then its 19" if there's a P538 then its a 25", if there are no numbers but a brown board with green lettering and a funny looking cylinder attached to the flyback, this is the zenith version of the K7191 (others may be able to add more specific info hint, hint)

The K7191 manual can be found here:  (but this only pertains to the P447 board)http://www.mikesarcade.com/arcade/monitors.html

if you need the schematic for the P538 I can send it to you--it is different and does have a few key different parts than the P447 board

[menace]

How to degauss your monitor--by Randy Fromm

------------- Modified by saint -----------------

Randy Fromm has made it clear he does not want any of his copyrighted material reposted on the Net. It's unfortunate because there's lots of good stuff, but please do not post anything from proprietary material (including the Blue book) here.

Sorry....

--- saint

[menace]

oops--didn't mean to step on anyones toes there...

Here's how I did it--not as eloquently written.

The monitor can be on or off, but on is preferable so you can see the effect .  Take your degaussing coil (or even a household magnet--not too powerful--don't want to suck the fillings from your neighbour's teeth) and starting in the center of the tube, make a spiral action, progressing farther and farther from the tube, out to about 6 feet (further if you are using a powerful magnet).  If you are using a degaussing coil (from therealbobrobert or elsewhere) it is recommended that you flip the coil so it is laying perpendicular to the tub before shutting it down.  That's it!

With my pc monitor I had to turn it on every 30 minutes or so for a minute or 2 to get the built in degauss coil to clean any artifacts (I had a red blob in the corner that wouldn't go away--much better now)  The reason for the every 30 minutes is that the thermistor that controls the degauss coil needs to cool down before it will restart the coil.  hope this helps!

[RetroJames]

Great thread, here is my contribution.  I just read this as I head towards an 8-liners chassis + tv tube = Arcade Monitor project.  It really pays to read the BASIC theory behind the technology you are about to mess with.

http://electronics.howstuffworks.com/tv.htm

[menace]

Understanding vertical limits and sizing of arcade monitor screens Courtesy of WPCMAME:

There is one thing that you must understand about graphic cards. They can't control the distance between the lines on the monitor. Modern monitors can auto-adjust so that the image fills the entire vertical height but with an arcade monitor the only way to change the vertical size is the knob marked "Vertical Size" or "V.SIZE".

Normally when you put a game into a cabinet you adjust the monitor so that the image fills the entire screen. The problems start when you put a PC into the cabinet and switches between games with different vertical resolution. You don't want to mess with the V.SIZE knob every time.

What you have to do is to fix the number of lines you want your monitor to display and then accept that some games doesn't fill the entire monitor or are clipped at top/bottom. If you accept that the game display is a bit distorted you can use stretch but watch out for the refresh rate (more about that later).

So here is a little guide.
Look at what games you want to play and what resolutions they got. Most horizontal games use  224,240,248 or 256 lines. vertical games on a horizontal monitor use 256 or 288 lines.

Lets take two cases.
1. You don't play vertical games on the horizontal monitor but you do play some games with 248 lines.
To adjust your monitor, use a resolution with 248 lines and adjust the monitor so that the image fills the entire height. I don't know what pixelclock the  ArcdeVGA card uses for its resolutions so I can't help you adjusting the horizontal size. Best thing is probably to use 320x240 and then adjust the monitor so that the black borders on the sides are the same size as the ones on top/bottom. If you use advancemame use a resolution of 330x248 (4:3) and adjust it so that it fills the entire monitor.

Now with 248 lines on your monitor you will get black borders on all games that uses less than 248 lines. 240 line games will give you ~3% black borders and 224 line games give ~10%.

2. You want to play vertical games with 288 lines on your horizontal monitor. Adjust the monitor in the same way as above but use a mode with 288 lines (e.g. 384x288). Note that vertical games don't use the entire width of the monitor so it doesn't matter if you can't see the corners.
With 288 lines on your monitor you will get big black borders on all horizontal games. 240 line games will get 20% and 224 line games get 29% or almost a third!

I use around 280 lines (missing a few lines on vertical games) on my 25" monitor which means that horizontal games is the same size as on a ~20" monitor. I probably wouldn't set it up with more than 256 lines on a smaller monitor.

What about stretch then?
MAME got a feature that allows you to stretch/shrink the image to any size that you want. With that feature you can have all games fill the entire monitor but with a more or less distorted image. There is one thing to watch out for: refresh rate.
Arcade monitors got restrictions on what refresh rate you can use for different resolutions. Approx. values are
240 lines 60Hz
248 lines 57Hz
256 lines 55Hz
288 lines 50Hz
This means that if you adjust your monitor to 256 lines, a game that fills the entire height of the monitor (with or without stretch) can't use a refresh rate of more than 55Hz. The limit is 50Hz for 288 lines. The choice here is if you want the game to fill the entire height (with stretch) or if you want it to run at the correct refresh rate. Some games are more sensitive to differences in refresh rate than others. E.g. horizontal scrolling games will show tearing effects. Note that either the refresh rate is correct or not. It is not better to run a 60Hz game with 57Hz than 50Hz.
You can't run your vertical games at their correct refresh rate on a horizontal monitor. Fortunately these old games usually doesn't use scrolling. One exception is BombJack where the background will flicker if not run at 60Hz. For BombJack I use a special mode with 247 lines and 60Hz to avoid the flicker but I miss some lines at top/bottom.

[Peter Baluk]

just another tip on degaussing a monitor.
place your game so it faces to the north or south when usind a degaussing coin as it will help in the process of degaussing as it lines up with the magnetic forces of the earth.

[JoeB]

just another tip on degaussing a monitor.
place your game so it faces to the north or south when usind a degaussing coin as it will help in the process of degaussing as it lines up with the magnetic forces of the earth.

I thought this trick only works for really big monitors.

The biggest problem when it comes to monitor magnetic interference is the speakers.  Before installing speakers in a cab, test them out by bringing them within the install distance while the monitor is on.  Move it around the screen.  If you notice significant interference, forget about using those speakers!

[Gideon]

Hi, I've got a question for the FAQ:  What is degaussing, and why would one want to degauss a monitor?  Please tell me, as I'm too embarassed to start en entire topic with this question.

[menace]

Because your monitor operates by an electron gun firing electrons at a phosphor grid it uses magnets and magnetic fields to aim the electrons that are being fired.  When a monitor gets a foreign magnetic field applied, the guns go out of whack and you get discoloration.  the purpose of degaussing is to erase those errant fields so that the monitor only has its own magnetic properties governing.  Most monitors have built in degaussing coils which operate for a few seconds when initially turned on.  This way the electrons hit the screen where they were originally intended and the picture looks as it should.

[Gideon]

Thanks very much!

[mnm]

Wells gardner K7191 chassis numbers

The K7191 manual can be found here:  (but this only pertains to the P447 board)http://www.mikesarcade.com/arcade/monitors.html

if you need the schematic for the P538 I can send it to you--it is different and does have a few key different parts than the P447 board

I have just got a P538 in a cabinet and it doesn't work, can you send me a copy of the schematics for it, as I would like to have a go at repairing it before I replace it.  Check your PM for my email address.

Thanks,
Martin

[Master Shake]

I have a hantarex polo, and im hooking it strait to VGA well now when I turn it on all I see is a white line across the middle of the screen. It

[Ken Layton]

Hantarex monitors are well known for taking out the vertical deflection ic chip as well as needing tons of capacitors.

[Master Shake]

so what shood i do???

[Ken Layton]

You'll need to take the monitor to a service tech or repair center and it's gonna cost ya.

[Sune_S]

I wrote this tutorial a while back. Hope you like it!
Using MAME with TVTool - for owners of Nvidia cards w/ TV-Out.

http://tvtool.info/forum/viewtopic.php?t=67&start=16

Here's the TVTool website:
http://tvtool.info/index_e.htm

-Sune

[Tilzs]

My monitor only fits in my cocktail upside down because coin mechs on the coindoor hit the monitor's PCB when the coindoor is closed. Can I make my monitor display updside down?

Yes you can by a technique known as yokeflipping. You can find out more about it here
http://www.dameon.net/BBBB/yoke.html

[menace]

Monitor Interference fix as provided by Ken Layton:

If the pattern is "herringbone" (as the experts call it) which newbies would call a fine "worm wiggle" you need to connect a jumper wire on your power supply between the "Frame Ground" terminal and the DC output Ground terminal.

The FG terminal on the power supply should get jumpered to the either one of the GND terminals on the power supply. FYI those GND terminals are the DC output ground.

[menace]

Question:  What is the specific function of a 1:1 Isolation transformer?   Isn't  it supposed to keep the AC at a steady 60hz?  Keep the spikes out so the monitor doesn't blink?

Answer (courtesy of Ken Layton): As pertaining to commercial arcade games the function is solely to isolate the monitor's "hot" chassis from all other components in the cabinet and keep you from frying if you touch the chassis. Only the monitor is connected to the output side of the transformer and nothing else.   The transformer was not designed as a voltage regulating/spike protecting unit.  It is a safety device for sure.

[Jomac]

Here is some more Monitor ID information also sent to Bob Roberts , There is a heap of stuff I haven't documented on my website about chassis that are re-badged and sold by various companies , if you get stuck or not sure what chassis goes with what CRT , dont be scared to ask , there are heaps of chassis and CRT's out there that are interchangable .


 
These are some things I found on Bob Roberts webpage:
If you have a look the chassis ID'd as Kortex , T & E and Kortex KTA-915 and Sharp Image SI 319  , all these 4 chassis are the same they are all Kortex KTA-915's just various batches of the same chassis. Kortex and Sharp Image are the same chassis all manufactured by the SeeJoo Corporation in Korea.
 
Also note the Sega MC-2000-S , this chassis was never made by SEGA , it is an early Nanao chassis made by a sister company of Nanao called Kaga Denshi The correct model number is KZ-20EN-L this used the standard 12 pin neck board.
They also released a 10 pin version KZ-20ES that was later replaced with a Nanao MS7-20L .
 
There is another chassis ID'd as Kagi  , this is almost correct but is actually one of the very first Kaga Denshi chassis , they also were a standard 12 pin type , the only difference between the 14" and 20" version was the flyback , 14" flyback was MSH-D548 and 20" was MSH-D562 , this chassis was replaced by the later KZ-20EN-L also known as the SEGA MC-2000-S and are interchangeable.
At the same time a korean universal replacement was made and badged as "Orion" , the first revision was an OC-2021 and later the OC-2022 , over 300,000 of these were sold in Australia alone as they were very reliable and only 1/5 of the cost of the Jap monitors ( Kaga / Nanao / Sega )

It's very handy to note that the KZ-20EN / Mc-2000-S will work on any 13 /14 / 19 inch CRT that the neck board fits on , for example Mitsubishi , Toei , AWA , Phillips , Orion , Kaga Denshi and various older CRT's used in cocktails that have the same neck pinout.
 
The chassis ID'd as Korean AP-0621 and Korean AM-0316 are the same chassis labelled incorrect , it is actually one of the many chassis made by Orion , this model is the Orion A-1 chassis made in Korea.
 
The Wei-ya 826HR  was also sold as a "Glendale" chassis with the same part number , interestingly Wei-ya , Pentranic , Rodotron and Glendale all come form the same factory.

After playing around with monitors full time for the past 21 years there is probably more stored away in my head than I could ever document so dont throw anything out until you ask

[melmo]

What are the most common game resolutions, (i.e. ega, cga, vga...)

im looking at building a traditional cocktail arcade macine so moitor res will be highly releven to the PCBs (games) that i lll be able to play once the machine is assembled will be restricted by the type of monitor i purchase.

Melmo

[Ken Layton]

90% of commercial arcade games use standard res CGA monitors.

[DarkKobold]

A picture of a CRT would help this thread - Identify where the yoke is, where to measure for vertical and horizontal impedence, etc. I've been reading on diy XY monitors, and I am wondering what they are talking about, since it doesn't seem like it would take too much time to wind the wires... Also, what is the glass thingy at the end of every monitor?

[MonitorGuru]

If you check 8liners.com's chassis page, they have pictures about how to measure impedence and how to identify tubes/etc. However something here would be good too.

Winding wires:   First you need to have a supply of fine/pure copper wire. Also it must be sealed with something to prevent shorting (it isn't a bare wire..if it was it would not work). It then must be wrapped exactly within a certain area and at a certain thickness.  The length of the wire + the width + the way it's wrapped + the purity of it all affect the impedence, and the resulting affect on the electron beam.  No one would ever be able to handwrap it the same twice, let alone match the impedence correctly. You'd have a very strange display with tons of geometric impurities that could never be adjusted out.  

It's a nice idea, but it just ain't gonna happen.


The glass thingy at the end of every monitor?  You mean the neck of the tube?  It's part of the entire tube. The yoke only sits around it.

To paraphrase "Airplane!": "Ever seen a CRT tube nakked?"

Here are 2 links:
http://www.ionpool.net/arcade/tubeswap/tubeswap.html
http://coinop.org/repair/Monitor_TubeSwap.aspx

Specifically this picture:
http://coinop.org/repair/monitor_tubeswap/05_TV_tube.jpg


The tube is thick at the front (1" glass), moderately thick (1/4") on the tapered sides, and extremely thin around the neck (1/16"). The neck houses the heaters, grids and electron guns.

[menace]

These are the typical resistance values between pins for the K7191 HOT (2SD1398) and Regulator (STR30130).  This may not tell you if the chip is going to operate properly but you will be able to tell if its blown or not.

Taken as label side up with the digital ohm meter set to "diode".  The first value indicates where to position the black lead(-).

2SD1398
1 to 2 open
1 to 3 53
2 to 1 477
2 to 3 511
3 to 1 53
3 to 2 open

STR30130
1 to 2,3,4,5   open
2 to 1,2,3,5   open
2 to 4            1667
3 to 1,5         open
3 to 2              587
3 to 4            595
4 to 1,3,5      open
4 to 2            1065
5 to all           open

Slight variations are ok.

[Ken Layton]

Those readings only apply if you are using a digital (electronic) multimeter and only if it has a "diode test" function. Readings are much different if you use a conventional analog (meter & pointer) style multimeter.

[menace]

http://www.seuservice.com/search.html

Click above for manuals for select sega games.  You can also contact their customer support people and find out if they have the manul for a game otherwise unlisted. (compliments of Ken layton)

[menace]

I can't believe I have never been to this site before but nonetheless, if you want a great cross-referencing site go here:

http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search

type in your part number , for instance the K7000 HOT is a 2SD1398
and you will get the more common nte part number for it (nte2302)

please keep the "i knew that--were you living under a rock?" statements to a minimum 

[menace]

Tube readings--you can get donor tubes from tv's and match them to the appropriate chassis (from ebay, your workbench or wherever)

[menace]

info on the zenith K7000A chassis as provided by Ken Layton:


Around 1990 or so Wells-Gardner was getting so many orders from game manufacturers that they were falling behind in production. The k7000 was their most popular model at the time for arcade video games. So they subcontracted with Zenith Electronics for Zenith to build the k7000 MAIN circuit board and NECK board (but not the remote adjustment board). This became known as the "K7000A" chassis. It did not have the usual "P447" or "P538" numbers silk screened on the circuit board like the genuine Wells-Gardners did. Instead the main board is silk screened 204-2205-07 and the neckboard is silk screened 204-2203-02.

The easiest way to identify this version is that there are TWO PINK wires going to the suction cup whereas the standard Wells-Gardner k7000 has ONE RED wire going to the suction cup. It is unfortunate that Zenith chose to partly redesign the circuit board from Wells-Gardner's design in order to use a proprietary Zenith made flyback. This particular flyback (Zenith numbers 95-4149 and A-15945) is no longer available anywhere thus making this chassis unrepairable should the flyback fail (a common problem). The flyback for standard Wells made k7000 (the 0528 flyback available from many suppliers) will not physically nor electrically work to repair the Zenith made chassis.

So if you have a k7000A chassis and the flyback is bad, then you're only hope to repair the monitor would be to either get a working regular k7000 Wells-made chassis (direct plug 'n play swap) or order an 8liners.com universal replacement chassis.

BTW, the k7000A uses the same cap kits as the regular Wells-Gardner K7000 monitors. Zenith kept the same component designations (and values) on the pc boards at least.

Oh, and to further confuse people, Wells used (mostly) Zenith picture tubes in both versions.

[GalaxyForce]

My monitor was just recapped and now it doesnt work (wont turn on) , any ideas?   

[MonitorGuru]

Did you do the recapping or did a "professional" do it?

Without more details, here are my thoughts...some may be blatently obvious, but may not to some.
- Did you reconnect the power correctly? (Test if there is 120 volts where the power comes into the chassis)
- Did you blow the fuse?
- Did you remember to reattach the ground wire that surrounds the outside of the tube and plugs into a pin on the neckboard?
- Did you reattach the anode cap correctly?
- Is there an orange glow in the neck but just no picture?
- Is there a high pitched whine when you have your ear close to the chassis? (not all people can hear this if you have damaged high-end (15.75KHz +) hearing.)
- Did you reattach the yoke wires correctly?
- Did you reattach the video input signal correctly?
- Did you double check every capacitor is installed correctly for polarity?

Start with that list and see where it leads you.

[menace]

so you have your randy fromm's flow chart but aren't sure what to do with this new fangled digital multi-meter...

On a digital multimeter you should have AC volts, DC volts, Resistance (in ohms), milliamps, and Amps--some have special diode reading function and some also have npn ,pn, transistor readings.

For a (typical) arcade monitor, AC volts comes in off of the isolation transformer 110-120 (sometimes 100 if its nintendo or something).  It is then converted to DC volts on the board.  Therefore any measurements on the board should be done in DC unless you have some weird type, and more than likley you should ask about it first anyways before believing everything you read on the web  . 

The DC volt range can go anywhere from 5V up to 250V (or higher) so it helps if you know what voltage you should be reading before you do it (i.e. refer to your flow chart)  To get your reading attach the black electrode to the frame or the ground of the chassis and use the red to probe for measurments (and don't be dumb about this--you are working with live electronics). 

To test components, you should always remove them from the board unless your device specifically allows you to leave them in.  An example of this would be an ESR meter to measure caps.  But for all resistors, diodes, transistors the part needs to be removed so that the circuit its in doesn't confuse your readings.

For transistors, you can A. get a known good one to compare it with, B. Measure it based off the flow chart (typically the HOT is an easy one to find out if its bad or not) .  For integrated circuits, you pretty much have to replace it since so few people would have the equipment to test these.  For capacitors all you can really do with a multimeter is see if its open or closed.  Like i said earlier, if you have an ESR meter you can actually test this but again its not your average piece of equipment.

[Navmaxlp]

Just a quick thing about transistors, diodes and the testing of them. These things are basically switches. They use junctions that require a voltage to turn them on. Most Diodes and trasistors use a silicon based substance for the junction which take a small voltage to conduct.

Now what is my point? It is this...if you use a digital multimeter to test these things, the PN junction will forward bias from the multimeter's output. In other words, do a resistance check on the diode or transistor.  For a diode, with the positive lead on the Anode and the negative lead on the cathode, you should read a short and with the leads flipped around, you should read open.

Transistors work the same way but are a little more complicated in that they are two junction switches. Junction one is emitter to base, and junction two is base to collector. You can perform the checks in the same manner as the diodes but as there are different types, I cant say where to put the leads.

Just know that when testing a junction, try it both ways. If it's a good junction it will be a short one way and an open the other way. Hope that helps someone and that it wasn't too confusing. Let me know if you need more info.

Oh and by the way, Menace has a good point about removing components from the circuit. I can't tell you how many times I've gotten cocky and left them in only to be proven wrong.