Author Topic: Wei Ya and TV tube - Complete (Read 7149 times)

cornishHen · « **on:** March 14, 2008, 04:56:57 pm »

I just received my CH-2620H Wei Ya CHASSIS from alva amusements that I was hoping to hook up to 19" Sanyo TV tube ( 10 pin 3.2 ohms/13.7 ohms). After plugging everything up without a video signal, I get a high pitch hum/whine and a light green screen. I am hestitant to splice in the video signal from a working centipede machine until I feel comfortable this is even safe to be around. Anyone else attempted the Wei Ya chassis/TV Tube combo? Any adivice?

grantspain · « **Reply #1 on:** March 14, 2008, 05:59:13 pm »

waiting for signal,you get the same when adjust the horizontal hold way out
light green probably needs screen volts and colours set up

cornishHen · « **Reply #2 on:** March 14, 2008, 06:52:48 pm »

Thanks... Putting signals to it produced an image. I was just a bit spooked by the initial sound without the video signals. It's got a image squashed horizontally. I'll mess with some of the adjustments tonight.

One other thing...This is a negative synch chassis, and I was hoping to put it into my pole position cab. The chassis only has one video input connector..Red, Green, Blue, Black, White..The pole position cpcb has two video connectors that was orginally on a G07 ( one with four wires Red,Green,Blue, and Purple) (the other with 1 purple wire. I'm guessing that second wire is a synch wire? Will I be able to simply splice that second wire to the black or white on the Wei Ya?

Thanks!

grantspain · « **Reply #3 on:** March 14, 2008, 07:19:27 pm »

sync is gonna be one of the purple,not familiar with go7 chassis but if you want to be sure then trace to the game board edge connector
if it were me i would just connect up the rgb and then try each option with the sync,can't do any damage
obviously white on the wei ya is sync

cornishHen · « **Reply #4 on:** March 14, 2008, 07:26:32 pm »

thanks..i'll give it a try tomorrow..

cornishHen · « **Reply #5 on:** March 15, 2008, 01:01:23 pm »

I got pole position showing on the tv tube/Wei Ya combo.. So far I am very happy with the results from the Wei Ya.

Just two minor problems.
#1 The screen is like a mirror image( see pic )
#2 The screen is not wide enough..I tried to adjust the width coil but it seems to have no effect.

Any ideas?

grantspain · « **Reply #6 on:** March 15, 2008, 01:14:28 pm »

reverse the horizontal yoke plug to correct the mirror image
look for a width jumper on the chassis or horizontal sub width

cornishHen · « **Reply #7 on:** March 15, 2008, 01:30:13 pm »

When you say reverse the width coil you mean desolder and flip?...Not any room to rotate..possibly flip it.

As for jumpers, what should I be looking for? The second picture shows possible jumper location? ( VR2 H.Width)

Kevin Mullins · « **Reply #8 on:** March 15, 2008, 01:58:51 pm »

Quote from: cornishHen on March 15, 2008, 01:30:13 pm

When you say reverse the ~~width coil~~ you mean desolder and flip?...Not any room to rotate..possibly flip it.

He mentioned flipping the YOKE plug...... there are four leads coming from the yoke down to the chassis. 2 for vertical deflection and 2 for horizontal deflection. They can ONLY be swapped with each respective lead. Meaning only switch the horizontal as a pair and only swap the vertical as a pair. (which you don't need to touch the vertical pair at all)

Read Bob's page to better understand what this is about.
http://www.therealbobroberts.net/yoke.html

If you post a full picture of your chassis we can probably point them out to you.

cornishHen · « **Reply #9 on:** March 15, 2008, 03:00:56 pm »

Oops! my bad..I misread grantspain's post.. I'll try switching the wires. thanks...

cornishHen · « **Reply #10 on:** March 15, 2008, 03:27:37 pm »

OK..That worked! Thanks for the info guys. Still sitting with a horizontal size problem.. Adjusting the width coil only increases the width by a tiny bit and at the same time causing some pincushion.

grantspain · « **Reply #11 on:** March 15, 2008, 03:43:51 pm »

would need to see a schem to see what would help

qrz · « **Reply #12 on:** March 15, 2008, 05:50:59 pm »

if this was an existing tube/yoke on a new chassis, there may be a need to add some capacitance to the h output to obtain the proper pulse width/timing .
i'd start with a 500pf cap ( PICO farads, i.e small) at 2kv connected from the collector of the hot to ground.
this should widen the pic some . note the increase and the needed value may then be extrapolated.

note : the h output pulses are typically 1000 - 1400vpp with a pulse width of 11-13 micro seconds (at 15khz)
use high voltage precautions accordingly .

qrz

cornishHen · « **Reply #13 on:** March 17, 2008, 04:50:54 pm »

Well i've looked around for a 500pf 2kv cap.. I tried mouser/jameco/ebay. Any suggestions where to order such a cap? Is this a possibly a situation where I might need to try a range of caps to get the adjustment i'm looking for?

I just ordered a single cement resistor from mouser last week and got burnt on shipping..

qrz · « **Reply #14 on:** March 17, 2008, 05:06:34 pm »

500pf was just a starting point . if u can only find a .001 uF thats ok as long as the voltage is no less than 1500v

could probably range from 220 pf to .002uF. still good to start low for testing purposes...

parts can be scavanged from scrap tv boards, or purchased new .

yes, availabilty and shipping can be an issue .
had needed an ic for a comp monitor . found decent pricing but needed to order 2000 pcs min ( per mfg)

was able to source elsewhere in a more managable quantity....of course , at a higher $

qrz

Ken Layton · « **Reply #15 on:** March 17, 2008, 05:22:19 pm »

in general, most of these chassis have a "width range" jumper wire (usually colored red or black) around the center of the main board. There'll be two silver 'posts' sticking up and the jumper will already be plugged onto one of them. They should be marked "N" (narrower) and "W" (wider). I think the factory usually plugs the jumper wire into the "N" (narrower) post. Since your picture is too narrow, you need to unplug it from the "N" post and plug into the "W" post instead. Of course you need the power off when doing this.

cornishHen · « **Reply #16 on:** March 17, 2008, 05:28:33 pm »

grantspain had mentioned a jumper, but having grown up working on computers, I was looking for a little square plastic piece as opposed to a wire jumper. I'll take another look when i get back home. thanks..

qrz · « **Reply #17 on:** March 17, 2008, 05:31:28 pm »

never seen this chassis ( or it's schematic) . so, was unaware of the width range jumper . tnx for the info

but, isn't it kinda unusual for a mfg to make something that simple ?

qrz

grantspain · « **Reply #18 on:** March 17, 2008, 05:39:37 pm »

width jumpers seem to be common on far east monitors-nanao,sanwa use them on most models

Ken Layton · « **Reply #19 on:** March 17, 2008, 06:28:41 pm »

Kortek monitors have the jumper.

grantspain · « **Reply #20 on:** March 17, 2008, 06:38:39 pm »

i am pretty sure the width jumpers exist because the far east manufacturers use so many different tube/yoke combinations that they needed a chassis that could adjust thus,not 100% sure but it would make sense

cornishHen · « **Reply #21 on:** March 17, 2008, 07:36:26 pm »

I did find the width jumpers and it was jumped to N. I switched it over to W and gained alittle bit more width. I measured the burn in on the G07 that was orginally on this pole position and it is 14in wide. With the new Wei Ya chassis/TV Tube combo, I am getting a hair under 13.5. I suppose I could live with it, but I would really like to get it close to its orginal state.

Just glancing at the chassis, I can't pinpoint where the HOT actually is. I'll request a schematic from alva.

cornishHen · « **Reply #22 on:** March 27, 2008, 09:48:11 am »

just getting back to this issue as I have a day off tomorrow.. i found a local electronics store stocking 390pf and 470pf 6kv caps. I was thinking of stopping by there and buying a nice range to experiment with qrz's suggestion. I still do not feel confident in locating the hot on the CH-2620H Wei Ya chassis. I see no oval shaped transistors( like the 2sd870 on old monitors) There is a large 3 legged transistor next to the flyback that i'm suspecting to be the hot. Anyone out there have a shematic for the CH-2620H Wei Ya??

Ken Layton · « **Reply #23 on:** March 27, 2008, 11:26:54 am »

Better read Bob Roberts' tutorial on selecting width capacitors first:

http://homearcade.org/BBBB/width.html

These capacitors are special because they operate at high frequency AC and so have an AC voltage rating in addition to DC voltage. These are Metalized POLYPROPYLENE capacitors with at least a 200 volt AC (400 volts AC is prefered) and 1000 volt DC rating. Using the wrong type of capacitor in this circuit will cause it to catch fire! These capacitors are large physical size and generally colored either brown, blue, or orange. Typically located next to the yoke plug on the monitor main board.

You do know that some of the width coils Wei-ya uses you have to pull (or in some cases push) the adjustment shaft slightly to engage the the adjusting slug inside the coil?

cornishHen · « **Reply #24 on:** March 27, 2008, 01:18:15 pm »

ken, thanks for the info.. I just got back from the electronics store where I picked up a 390pf 3kV and 470pf #kv ceramic capacitor(s). After now seeing your post, I am guessing these are not the correct type. i'll hold off on that idea again. i really don't want to use my fire extinguisher yet.

As for the width coil adjustment, I did notice that while loosening the coil with my adjustment tool that it starts to slide out after several turns( it does appears to adjust the width a tiny bit). At that point I figured that it had unthreaded and there was nothing more to adjust. I'll try some different winding combinations.

Ummon · « **Reply #25 on:** March 27, 2008, 04:17:03 pm »

I'm assuming you're using a PP board, right?

qrz · « **Reply #26 on:** March 27, 2008, 08:05:13 pm »

Quote from: Ken Layton on March 27, 2008, 11:26:54 am

B
These capacitors are special because they operate at high frequency AC and so have an AC voltage rating in addition to DC voltage. These are Metalized POLYPROPYLENE capacitors with at least a 200 volt AC (400 volts AC is prefered) and 1000 volt DC rating. Using the wrong type of capacitor in this circuit will cause it to catch fire! These capacitors are large physical size and generally colored either brown, blue, or orange. Typically located next to the yoke plug on the monitor main board.

500pf is a small value . these are not special other than the working voltage of 2kv . MANY tv's use these (disk ceramic ) in the h-out for resonance ( "tuning caps" ) exactly as i have suggested .
adding a cap is the easiest- so, why make it difficult ? .

but if one insists on changing the other caps , then yes, YES - use the metal poly type of equal or greater working voltage.

i'd just solder that 390pf/3kv to the hot collector and gnd , then see what it gained . if still not enough, remove and try the 470pf ( if rated 1.5kv or higher) the same way . still not enough, use 'em both. remember , just testing to see what actual needs will be . i doubt that u will need more than .002uf max..
JUST BE SURE TO KEEP LEADS SHORT - typical 1200vpp present on the collector - ( DO NOT MEASURE )

qrz

cornishHen · « **Reply #27 on:** March 28, 2008, 08:56:13 am »

ok..i tried adjusting the width coil all the way out yesterday with no change, so I wanna give the capacitor solution a try. I've included a photo of 2 possible locations of the hot.. I am thinking it is the larger black transistor next to the flyback shown in the photo?

Also, when soldering the cap from collector and gnd, i know which is the collector but what is the best place for ground? would the screw used to attach the hot be correct?

qrz · « **Reply #28 on:** March 28, 2008, 01:57:32 pm »

the emitter is grounded . not seeing the xistor #'s makes it difficult to say which for sure .

per pic, this chassis may have seperate hv/sweep circuits

i'll need to do some research

qrz

Kevin Mullins · « **Reply #29 on:** March 29, 2008, 02:02:35 pm »

Quote from: qrz on March 28, 2008, 01:57:32 pm

not seeing the xistor #'s makes it difficult to say which for sure .

Agreed..... if you can pull some numbers off the larger transistors like the one you picture then it would be easy to identify as being the HOT or not.
Could also be a voltage regulator or such.
You may even find more than one transistor of that approximate size on the chassis.
(one of which is bound to be the HOT)

cornishHen · « **Reply #30 on:** March 31, 2008, 10:40:44 am »

Thanks for the replies..I will try and post some more info/pictures later tonight. This past weekend didn't allow any free time to work on this issue.

cornishHen · « **Reply #31 on:** March 31, 2008, 08:15:44 pm »

There are only 2 transistors attached to the chassis that I think could be the HOT, but i'm not sure which...

Here's some info:

The first pic below shows Q302 with markings C5296 6K2.

The second pic shows Q101 with markings K2628 6C3. Is this helpful?

qrz · « **Reply #32 on:** March 31, 2008, 08:24:06 pm »

the 2SC5296 is the HOT

2SK2628 is a MOSFET , likely used in the SMPS

specs @ www.alldatsheet.com

qrz

cornishHen · « **Reply #33 on:** April 01, 2008, 07:39:04 pm »

I tried soldering the 390 pf cap first...the width changed a tiny bit, so I tried the 470pf with again a tiny bit of change. So, I then combined the 2 caps and it the width is within a 1/16th of where I would like it to be. It still has some pincushion issues that I plan on trying to adjust. I've added some photos of the finished product. Thanks for the all the help everyone!

grantspain · « **Reply #34 on:** April 02, 2008, 03:03:03 am »

good job,looks great

Arm123 · « **Reply #35 on:** April 02, 2008, 03:14:07 pm »

yup... nice work ! congratulations


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