What fixed your game today / general repair log

Hot air station ?

Recently had a Konami Violent Storm PCB that had missing sprites and a color palate issue. Located some damage to the legs on the sprite generator at 7K, removed the chip and replaced with a donor. Everything is working as it should.
 
PCB: Sega / Gremlin Carnival Power Supply board
Symptom: no -12v and no -5v. Note -5v is created from the -12v
Steps:
1) checked for -20vdc on neg side of C5 = @-16vdc good
2) checked Q6 Emitter = @ -16vdc, base @ -15.8vdc and nothing on collector.
3) checked for continuity to gnd on Q6, collector was shorted
4) replaced Q6 with TIP112 (darlington transistor) but still nothing and don't know how to test darlington's
4) pulled Q6 and checked Q6 collector pad still grounded.
5) started pulling legs of parts on -12v line, r39, r37, got to c15 and short was removed
6) test c15 shorted, replaced with 10uf 25v cap
7) verified -12v and -5v good
Repair: Replaced C15 and Q6 (good measure)
 
I had a fellow drive to my place today because he heard I fix games. He bought a Mrs. Pacman for 300.00 today from a youth center non working.

He dropped it off and I looked at it for a bit then removed the board and cleaned all of the eeprom legs and a few of the socketed ram chips. Game came right up and plays fine.

So a good cleaning and a bit of time fixed this one.
 
Changed out a power supply in MK 2 I was putting together. Worked fine without sound board hooked up. With sound board, it was static, reboots, and the screen was all screwy. Checked power supply was running at 5.8v non adjustable (yikes!) ordered a new PS but found one in my stash and threw it in and now its working like a champ.
 
Centipede metal bridging traces causing it not to boot, bad 74ls32 in video circuit causing missing colors.

Did dig with blue dig dug character, bad bipolar prom at 8f on the later revision board.
 
Donkey Kong TKG-4: (all symptoms from same boardset)

Symptom: Rec'd Completely Dead

Resolution: Removed all socketed chips, cleaned legs, cleaned edge connector. Verified ROMs, two of the 2732's failed checksum in Romident. Re-burned.

Symptom: High Pitch walking (analog) sound

Resolution: Spot tested caps and all were within spec, but decided to cap the entire sound section anyway to no effect. Replaced 555 timer at 8N and now Jumpman sounds like he should. DK is now 100%.
 
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Just fixed a Roc n rope that worked fine except the sprites were in the wrong places.Cavemen and dinosaurs were mostly correct but a few were in the air but the main character was not visible and the rope was corrupt.The game played fine as far as you could get without being able to see the main character.

Anyway I figured the problem was in one of the 4 2114's that holds the sprite data and after changing them one at a time it turned out the fourth one fixed it-the one at F11.
 
I had a GORF CPU not booting. I found out that it had no clock and a low resistance between 5V and GND. I replaced U5 and brought it back to life.

My GORF was flaky so I re-pinned the edge connector for the PCB. Then the joystick would not work, so I had to re-pin that.

It has been a GORF weekend.
 
I had a GORF CPU not booting. I found out that it had no clock and a low resistance between 5V and GND. I replaced U5 and brought it back to life.



My GORF was flaky so I re-pinned the edge connector for the PCB. Then the joystick would not work, so I had to re-pin that.



It has been a GORF weekend.



Nice work! How do you even test gorf? Isn't it one of those board sets that have like 3 or 4 boards in a cage with a backplane? Or am I thinking of something else?

I did some carnivals this weekend

Board #1
Voltage - OK
u49 looked wierd, pushed on it and colors on screen changed, pulled old socket and replaced
Fluke bus test, address bit 11 stuck high
It was not stuck high but did have a square wave pattern
Found continuity with chip at u48, a tiny bridge under the CPU socket
Cut the bridge and replaced the CPU socket
Fluke bus test - OK
Fluke RAM long 0x8000 - 0x8FFF BTS C0
Swapped 8216 @ u47 and u48, ran test again, this time BTS error 0C
Pulled bad 8216, replaced with another
RAM now ok
Game works!

Board #2
Game works but has yellow garbage on the screen in various places
Bad ram @ U73

I am trying desperately to get rid of boards and clean up my basement to build a workout area and bathroom in my workshop but for every board I fix and sell it's like 4 or 5. Appear in their place :(
 
Yes, that is the one. I received a backplane without the cage in a purchase. The clock circuit is self-contained to that board and I had that board isolated as the defective one. I just powered that board on the backplane.

I always clean my basement to look nice, but can not help myself fixing things. I do things that bring me joy and a clean basement is not one of them.
 
Tried to take it easy today while I fight a cold, but had a burst of energy and decided to finally tackle an intermittent problem with one of my games.

Game PCB: Reactor

Symptom: Game gets stuck in test mode upon booting up; sound occasionally cuts out

Steps:Cursing, reseated connectors with with limited success

Repair: Repinned J3 and J4 connectors
 
I finally fixed the score display on my Fire Escape. I got rid of the IDC connector and was able to find some 7 segment displays to replace the broken one's.
 

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asteroids deluxe - plays blind, but doesn't seem to have video
after looking further it appears all the video was just shrunken in the y axis and and the top of the screen

4016 @ location B12 I think it was fixed it.

Happy Easter everyone.

-brian
 
asteroids deluxe - plays blind, but doesn't seem to have video
after looking further it appears all the video was just shrunken in the y axis and and the top of the screen

4016 @ location B12 I think it was fixed it.

Happy Easter everyone.

-brian
Tempest needs your love too ;)
 
Looked at tempest yesterday that thing is confusing me. I have an idea though
 
Wish this had a definitive conclusion but figured I would share. Its a thing called magic.
Game PCB: Moon Patrol
Symptom: Previously was working 100% and then no Sound but game plays
Steps:
1) checked PS and have correct +12 and +5 voltage
2) adjust volume and can hear static and pops through speaker
3) recapped all electrolytic caps on sound board. No joy still no sound
4) Was about to build a jamma adapter to troubleshoot further but had two spare Yamaha sound chips so swapped those in and now have sound.
5) replaced original sound chips one by one to determine which one was bad and still have sound with both original chips in. WTH.
Repair: Reseated Yamaha sound chips ?

Of course after typing this went back to play a few games and fuse f1 was blown. replaced it and will see if it happens again.
 
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z0ner and the order of the Phoenix.

Acquired said bird. Cabinet 6/10, but the original side art and control panel are still pretty decent. K4901 has neck glow but no picture, plays blind. Neither marquee or coin slots are lit. Coin-up switches are both broken but respond to a credit by rolling them. Player 1 is defunct. This one's been through hell, boys.

Went to pull chassis and neck board for examination. Taking the red "Y" from the flyback out of the neck board cracked about a dime-sized piece off. This one needed the Kragle and a nice jumper. Reflowed the header on the neck board only, after the voltage regulator and HOT came up AOK. Popped it back in and viola, we have picture. It's possible the neck board was cracked before I pulled "Y".

I cleaned the contacts on all 6 leaf switches with a business card (and they were filthy). P1 still wouldn't start. Troubleshoot at the PCB connector and got nothing. Troubleshoot at the Molex and finally figured out the contacts weren't conductive enough. Interestingly my metal file between just the contacts was enough to coin. Swapped with another leaf switch.

Marquee was missing both a bulb and a starter. Such a PITA to put in the starter - you basically have to do it blind. I couldn't test the ballast either due to this stupid design so I was risking killing the bulb. Luckily it works.

I'll replace the coin-up switches with ones where idiot(s) didn't break them off in the next few days, but we're golden and after about an hour I got a really nice high score (61K). Board seems to work great.

The one diamond in the rough is the tube is beautiful, and in great shape. No burn, and my B&K says all three guns are in the far right of the green.

Another one rises from the ashes :D
 
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