Author Topic: WHAT IS THE SWITCH ON THE MONITOR BOARD DO. MY MONITOR TURNED ON BEFORE (Read 8046 times)

ROBHAD · « **Reply #40 on:** July 22, 2009, 10:01:37 am »

JUST PUT IN ALL NEW FUSES IN THE WHOLE MACHINE.. AND STILL NOT PICTURE.. I WOULD THINK YOU WOULD HEAR THAT SOUND THAT A SIGNAL IS GOING THROUGH . BUT I DONT. IAM LOST.

ROBHAD · « **Reply #41 on:** July 22, 2009, 10:17:33 am »

i just retested all the important wires with my voltage tester.. they all gave me a strong signal. what do i do next..

ROBHAD · « **Reply #42 on:** July 22, 2009, 10:23:35 am »

i didnt see any other fuses on the board , but then again i didnt take it apart.. is there normaly more than one?

ROBHAD · « **Reply #43 on:** July 22, 2009, 11:33:50 am »

JUST TOOK IT ALL APART.. THERE IS NOT OTHER FUSE..AND NOTHING IS BURT. MY NEXT PLAN IS TO GO AND TAKE EVERY WIRE OUT AND PUT EM IN ONE BY ONE.. I DONT KNOW WHAT ELSE TO DO

ROBHAD · « **Reply #44 on:** July 23, 2009, 09:56:58 am »

Still have the same problem. did you guys forget about me?

Nipedley · « **Reply #45 on:** July 23, 2009, 10:56:27 am »

I'm afraid I have nothing else to suggest

If it isn't loose connections or blown fuses then that points to something more serious.. which would mean at the least taking the chassis out and replacing some parts (without knowing what that switch does, we can't really say for sure). Depending on your skill level, you might want to send it off to someone to repair it if they offer a service for your monitor.. or maybe even find a new one if all else fails.

ADD:
Could you have a look, see if you can find any other names or model number identification and also tell us the size of the monitor. Maybe a hi-res picture of the chassis also would help someone here identify it if you can't find any other info on it.

ROBHAD · « **Reply #46 on:** July 23, 2009, 11:28:41 am »

i assumed that switch was sort of standard on the board. iv looked there is no other numbers. or markings.i guess my next step is to figure out in detail what that switch is for and how i can get it to activate again. i dont think the monitor is bad. i really think iam just missing something. i cant uderstand why a voltage switch wouldnt just turn back, in a worse case you just pull the power supply for a momemnt and it would come back. but i dont get anything. its almost like its not getting power but it is. there is only 3 things to conect. 1 is the power cord. 2nd is a blue wire that gets connected to the game contols 3rd is a connection from the pcb to the back of the monitor board, i guess this wouldnt be getting to me so much if it gave me a sign that is was turning on.. iam woundering it maybe... hum..there is a voltage box that has if i rememeber a button for 120/240 volts.. maybe that has to be reset somehow.. ill take a pic of it .. let me know what you think

ROBHAD · « **Reply #47 on:** July 23, 2009, 11:39:07 am »

the top picture is the box that i was talking about

Nipedley · « **Reply #48 on:** July 23, 2009, 11:49:19 am »

From the pictures, that power supply box in your picture is for the game board, sadly should have no effect at all on the monitor. What that does is purely power the game pcb's in the cabinet.

Out of interest what region are you in? For some reason I thought new york but I have no idea where I got that from or if its right!

Oh and nice catch of a Virtua Cop there, im very envious

I love that game

It does seem like there's something amiss but without being there it's difficult to tell what! That big transformer with the 120v on it is what is powering your monitor, check through the entire wiring from that transformer back to the plug and up to the monitor and make sure nothing's loose or hiding a fuse somewhere..

Nipedley · « **Reply #49 on:** July 23, 2009, 12:33:53 pm »

Sorry to double post but I've been doing some digging and found out some info. I couldn't find anything on your specific GMK-20P but I found a lot on similar Hitachi GMK chassis. They are standard res - medium res switchable chassis, which means they can display different resolutions of gameboards. And that is changed by a switch. I have a feeling this is what has happened here, that you flicked the switch and changed the monitor into Standard Res mode while it was on (not advisable!) and the gameboard you are using is a Medium Res board, so the signal was not what it was expecting.

Needless to say this usually fries something, our own grantspain said in another thread I found that the HOT (horizontal output transistor) is usually the culprit.

I think step 1 here would be to confirm thats what the switch does (rub the dust off around the switch and look for any markings, saying Res, 15khz, 24khz etc.)

If this is what's happened then you would need to remove the chassis from the monitor, identify the HOT and replace the part, then hope nothing else was damaged too

ROBHAD · « **Reply #50 on:** July 23, 2009, 01:55:16 pm »

checking on that switch.. lol.. i had to get out my magnifyer..lol..
the olny markings on it was 431Z and on the board S701

Nipedley · « **Reply #51 on:** July 23, 2009, 02:07:24 pm »

Shame there isnt any more evidence but I think theres a high probability that's what it was. It's a medium res game, switchable sync chassis... that's a switch.. lol and I did find one picture of a similar model and the switch was close to where yours is.

Sad to say it but I think you're going to have to do some repair work

Shame for such a small error as well.

ROBHAD · « **Reply #52 on:** July 23, 2009, 02:17:16 pm »

ok .. how do i replace "the hot" ..

Nipedley · « **Reply #53 on:** July 23, 2009, 02:56:43 pm »

What is your skill level as regards arcade chassis/electronics/soldering? If you put your location and aren't up to it, it's possible a close byoac'er could help you out.

First you would need to remove the monitor from the machine... then discharge the monitor (there is a guide for that in the 'MONITOR FAQ' at the top of the monitor forum), that part is very very important, then after that you can remove the chassis (the pcb) from the monitor. Then you need to identify the HOT (horizontal output transistor) and desolder it, remove the part, install a new one and solder it back in.

It's possible something else could have been damaged too, but others will be more knowledgeable about that than me..

ROBHAD · « **Reply #54 on:** July 23, 2009, 03:31:12 pm »

iam a beginger with monitors .. but ive dont cap kits before.
iam looking at what i think needs to be replace .. there is the wire Red that goes to the monitor..
if thats it.. then i need to defuse the monitor..( i hate that)
and the one i have has a part on it that looks like there should be another wire similar to the red one.. but there is nothing there..

Nipedley · « **Reply #55 on:** July 23, 2009, 03:43:41 pm »

If you've done a cap kit then it won't be too much more difficult. The horizontal output transistor as the name suggests is a transistor. It will be fairly large, in the sense of maybe 2 - 3cm wide and a cm and a half high (that's just a general guide, yours may be slightly different), usually black in colour, and will probably be attatched to a heatsink. I attatched a picture of my HOT at the bottom so you know what sort of thing to look for, its very unlikely it will be exactly the same.

You shouldn't need to replace the flyback (with the red wire) however you will need to discharge/defuse it in order to take the pcb off to do the soldering. There are usually a few large transistors on your board, seeing how we cant know how extensive the damage is I would recommend you order a replacement for all the large transistors, just incase.

You will need to take down the part numbers of the transistors to order the replacements.

Kevin Mullins · « **Reply #56 on:** July 23, 2009, 03:50:21 pm »

Quote from: ROBHAD on July 23, 2009, 03:31:12 pm

and the one i have has a part on it that looks like there should be another wire similar to the red one.. but there is nothing there..

If you are looking at what I think you are looking at, then that is a screw hole.

Nipedley - What kind of monitor do you have ?
That IC looks more like a Vertical IC.
A typical H.O.T. is a large three legged transistor.

Nipedley · « **Reply #57 on:** July 23, 2009, 03:58:03 pm »

Hmm it's possible, I have a Hantarex Mtc 9000. Off the top of my head I thought my HOT was a TDA1670, maybe that was one of the other parts I replaced (all of them!).

Nevertheless, the appearance should point him in the right direction.

ROBHAD · « **Reply #58 on:** July 23, 2009, 03:59:28 pm »

i just noticed this thing is made in japan.. its going to be hard to find the part. i need to find spec sheet on this..

Nipedley · « **Reply #59 on:** July 23, 2009, 04:02:35 pm »

Even if it was, the parts used on the chassis should be mostly universal and available. I couldn't find a manual or anything referring to your chassis, at best 3 out of focus japanese (I can read japanese but not when it's out of focus) schematics pages for a similar GMK series chassis. Your best bet is to replace every big black transistor that looks like that, it won't cost you that much and you can be safe in the knowledge all of them will work if any of them have been damaged.

ROBHAD · « **Reply #60 on:** July 23, 2009, 04:05:30 pm »

any idea where to buy them..
or should i just buy a new monitor.. i was hoping this problem was goin to be easy

Nipedley · « **Reply #61 on:** July 23, 2009, 04:07:27 pm »

Kevin was right, that was my vertical deflection IC (it's been a while). Below is the picture of my HOT (yours should be similarish in appearance).

Again where are you? If in the UK, Cricklewood electronics have provided every component I've ever required. If they don't have it they may be able to source it for you. In the US I have no idea, as I'm in the UK

But they might ship to you anyway.

ROBHAD · « **Reply #62 on:** July 23, 2009, 04:26:42 pm »

iam in us..
how would i test that.. ?
the same way with the tester>

Kevin Mullins · « **Reply #63 on:** July 23, 2009, 04:31:39 pm »

Check with the diode/continuity function of your meter.
Look for any dead shorts between the legs.

POWER OFF !!

ROBHAD · « **Reply #64 on:** July 23, 2009, 04:53:25 pm »

I think i found the problem.. i just tested every circut . the power blug shows bad on the meter.. some of the soter on the board it touching the soter on the fuse holder. iam thinking maybe i need a new power cord.. iam attaching a picture

ROBHAD · « **Reply #65 on:** July 23, 2009, 04:54:12 pm »

and io did check that circut and it was fine/

Nipedley · « **Reply #66 on:** July 23, 2009, 06:11:05 pm »

It shows bad? How so? It's difficult to tell what you mean, and the flash whites out the picture so I can't see much there either

I wouldn't worry about the solder, that wouldn't have changed through the flick of a switch anyhow.

ROBHAD · « **Reply #67 on:** July 23, 2009, 06:28:29 pm »

yea that didnt do anything..
this is realy stressing me out.

Beretta · « **Reply #68 on:** July 23, 2009, 07:03:11 pm »

um if im not mistaken down you have to test resistors, transistors, and diodes OUT side of a circuit.. IE: you have ot remove it or you'll get mixed readings..

ROBHAD · « **Reply #69 on:** July 23, 2009, 10:02:44 pm »

iam not sure what to do next.. iam ready to give up ...

Kevin Mullins · « **Reply #70 on:** July 23, 2009, 10:17:22 pm »

You could always pull the chassis and send it to someone.

ROBHAD · « **Reply #71 on:** July 23, 2009, 11:00:42 pm »

i could but not tring to loose money on this.. and i know ill loose on the repairs...

Kevin Mullins · « **Reply #72 on:** July 24, 2009, 12:15:51 am »

Depends on who helps ya out.... where abouts are you located ?

ROBHAD · « **Reply #73 on:** July 24, 2009, 09:53:23 am »

new hampsire.
id fix it if i knew exactly what the problem was

SirPeale · « **Reply #74 on:** July 25, 2009, 08:24:14 am »

What part of NH? I live in Brattleboro, VT.

ROBHAD · « **Reply #75 on:** July 26, 2009, 07:13:51 pm »

right next to keene.
maybe you can come check it out sometime.

SirPeale · « **Reply #76 on:** July 27, 2009, 03:38:34 pm »

No kidding! Nice to meet someone local.

ROBHAD · « **Reply #77 on:** July 27, 2009, 04:23:14 pm »

super deal .. what do you have for games.. when can you check this monitor out.


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