Author Topic: 25K7197 black screen 135.6v need help! (Read 2691 times)

MrEnkei · « **on:** October 25, 2015, 06:23:24 pm »

Hi there, I bought Open ice arcade cabinet 3 month ago. This is a midway universal 4 players cabinet. I knew then the monitor was broken but I don't know why. I looked up at the chassis and saw a blow fuse and a crack on the flyback. I decide to order a recap kit, HOT and a new flyback from therealbobrobert.
After the complete rebuilt, I test it and nothing buzz in the tube. So I decide to look at the troubleshooting sheet in the WG's service manual.
Bad solder and bad contact are fixed. ( I found a lot of broken trace)
Ic4 was short, I changed it.
Now I got a buzz in the tube, black screen with distortion.
I check B+ at IC4 Pin4 and neck board P202 pin3, I have 135,6v. (From Earth ground)
C36 = 4.0nF ?!
C55 = no reading
Q11 = reinstall the older = no change
Someone can help me?
Thanks

grantspain · « **Reply #1 on:** October 26, 2015, 05:00:18 am »

you say you have a black screen with distortion,do you mean a blank screen with distortion?

135vdc is a little too high for b+ on 25" chassis,it should be 130vdc

MrEnkei · « **Reply #2 on:** October 26, 2015, 05:40:32 am »

Yes, blank screen is better.

grantspain · « **Reply #3 on:** October 26, 2015, 07:59:20 am »

have you put a video signal into the chassis yet

MrEnkei · « **Reply #4 on:** October 26, 2015, 09:35:55 am »

Yes, everything are plug to the arcade cabinet.

grantspain · « **Reply #5 on:** October 26, 2015, 06:15:29 pm »

your second photo
i can see that the crt pin guide has come off the tube,are all the pins ok?

can you post a photo of where you attached each wire on the neck card

do you have any tube heaters?

MrEnkei · « **Reply #6 on:** October 26, 2015, 06:37:47 pm »

What do you mean by tube heater? This is the element on the tube above de neck board? I take some pics.

MrEnkei · « **Reply #7 on:** November 01, 2015, 01:47:48 pm »

I will recheck every cap I installed. Just to be sure then the capacitance is okay.

grantspain · « **Reply #8 on:** November 01, 2015, 05:08:43 pm »

i would more inclined to check the power supply and game board,monitor looks like its running to me

Kevin Mullins · « **Reply #9 on:** November 01, 2015, 05:11:49 pm »

Quote from: grantspain on November 01, 2015, 05:08:43 pm

i would more inclined to check the power supply and game board,monitor looks like its running to me

That's what I was just wondering too.
The tube heaters appear to be on, and there appears to be some activity going on, so that's a plus.

Just for clarification purposes, is it playing blind?
(can you hear the game running, coin it up, play it, etc ... just no video on screen)

MrEnkei · « **Reply #10 on:** November 01, 2015, 06:25:03 pm »

Ok I will try it. There is a set up mode? Just to be sure to not be on the bad mode. (Like I said, I bought this arcade as is. The only thing I saw and heard was the bad fly back. )
Thanks for your help.

Kevin Mullins · « **Reply #11 on:** November 01, 2015, 10:58:42 pm »

That is set to normal running mode right now.
TEST (see arrow) would bring the game board up in a test or service menu of sorts.
The SERVICE button is basically a credit button, sometimes used for changing settings.

You should be able to turn the machine on right now and hear it start up the game, like hear the attract mode sounds and whatnot.
You should be able to coin it up and play it. (even if you can't see what you are doing)

So ignore the monitor for a moment...does the rest of the game seem to work?

MrEnkei · « **Reply #12 on:** November 03, 2015, 08:36:31 pm »

Damn! I got nothing. I flip the coin micro switch and there is nothing happen. Tomorrow I will check the voltage.

MrEnkei · « **Reply #13 on:** November 07, 2015, 06:03:11 pm »

Is it to high? How many ACvoltage the power supply was suppose to be? I've got 118acv in the wall plug.

grantspain · « **Reply #14 on:** November 07, 2015, 06:21:49 pm »

that's the ac input to the monitor-its a little too high but not off the scale
we have already deduced your monitor is working so you should now be looking at the low voltage power supply that runs the game board,you need to confirm +5 volts at the very least

MrEnkei · « **Reply #15 on:** November 07, 2015, 06:23:56 pm »

Yes, I ´m looking at this now. I had blow fuse and bad capacitor.

MrEnkei · « **Reply #16 on:** November 07, 2015, 06:26:49 pm »

Someting is bad there.

grantspain · « **Reply #17 on:** November 08, 2015, 03:33:03 am »

replace the entire power supply,they are cheap

MrEnkei · « **Reply #18 on:** November 08, 2015, 07:28:45 pm »

I think I will mame this cabinet but how to be sure than this monitor is working? When I will place my order for ordering new parts, I would like to know if I will buy the arcade vga card or not... I don't know what is the best way to go...

baritonomarchetto · « **Reply #19 on:** November 09, 2015, 12:48:31 am »

Even if you mame it a good working PSU is mandatory for the PC to jamma PCB.
Google for CRT emudrivers.


Main	Restorations	Software	Audio/Jukebox/MP3	Everything Else	Buy/Sell/Trade
Project Announcements	Monitor/Video	GroovyMAME	Merit/JVL Touchscreen	Meet Up	Retail Vendors
Driving & Racing	Woodworking	Software Support Forums	Consoles	Project Arcade	Reviews
Automated Projects	Artwork	Frontend Support Forums	Pinball	Forum Discussion	Old Boards
Raspberry Pi & Dev Board	controls.dat	Linux	Miscellaneous Arcade	Wiki Discussion	Old Archives
Lightguns	Arcade1Up	Try the site in https mode		Site News


Unread posts \| New Replies \| Recent posts \| Rules \| Chatroom \| Wiki \| File Repository \| RSS \| Submit news