What fixed your game today / general repair log

[vintagegamer]

Atari Lunar Lander: marquee light not working

Issue: bad starter

More info:

Lunar Lander: 2025.

Still mindblown that I was able to get this. Starting very slowly. I feel like Kirk wiping the smudge off of V GER

forums.arcade-museum.com

 

[SNESNESCUBE64]

From today's day of work:

Game: Donkey Kong
Symptoms: Distorted Sound
Troubleshooting Steps: Hooked the board up to my bench to make sure that it wasn't the board. Game board was fine. Looked at the amp, it was recapped but the transistors were original. I figured it was probably that so I replaced both the A940 and C2083. Sounded great after that.
Solution: Bad A940 and/or C2083

Game: Silverball Mania Pinball
Symptoms: Left flipper not working great. Somehow works just fine when both flipper buttons were pressed.
Troubleshooting Steps: First step was to check that flipper voltage was present, that checked out fine. Next step, check for cold solder joints. It had lots but the problem persisted after reflowing. I checked the coil itself and noticed that the end of stroke switch was really crusty. I replaced the EOS, that was it! Back up and going.
Solution: Bad left flipper EOS.

 

[VectorCollector]

 

[vintagegamer]

Game: Ms. Pac
Issue: monitor stopped working, played blind

Troubleshooting:

1. Disconnected 2-prong monitor connector from monitor, inserted DMM leads in on female side
2. Powered up game, connector was reading 122.7 VAC
3. Powered off machine, reconnected monitor, powered game back up, video was back.
4. Powered down game, hit monitor connector and main game power switch with contact cleaner, allowed it to dry

Issue resolved (for now)

 

[jimbodeanny]

Fixed the G08 (again) in @CarrieZ 's Space Fury yesterday. The night before, I noticed the monitor lost picture at some point while I had the games on. I could hear deflection chatter but when I tested voltages, I realized I had no HV. Pulled the monitor, gave the entire HV board a thorough reflow, especially the flyback, T900, the 100v satellite board (including the red/black wires) and anything else that looked spotty. Fired it up and had a nice picture again. Back in business and not a moment too soon with the Halloween party in just a couple days!

Game: Space Fury
Issue: G08 lost picture, game plays blind (no HV)
Solution: Good reflow of the HV board

 

[VectorCollector]

Fixed the G08 (again) in @CarrieZ 's Space Fury yesterday. The night before, I noticed the monitor lost picture at some point while I had the games on. I could hear deflection chatter but when I tested voltages, I realized I had no HV. Pulled the monitor, gave the entire HV board a thorough reflow, especially the flyback, T900, the 100v satellite board (including the red/black wires) and anything else that looked spotty. Fired it up and had a nice picture again. Back in business and not a moment too soon with the Halloween party in just a couple days!

Game: Space Fury
Issue: G08 lost picture, game plays blind (no HV)
Solution: Good reflow of the HV board


View attachment 858058

You really should use a HV probe and confirm the HV is correct. Your pic looks slightly "zoomed-in / bloomed" to me (i.e. HV too low). Some may say it looks fine.

To me, it needs to be sized down or the HV turned up. Since your comments in another thread notes that the lower voltages are under spec, I would suspect your HV value is also too low (should be 19.5kV). Might want to recheck the actual value.

Also it's good advice to also never allow a color vector to draw lines outside of the screen boundaries. About 0.5-1" away from the edges is best so as to not over-drive the transistors etc. YMMV

MEMORIES FROM 12 YEARS AGO:

 

[jimbodeanny]

You really should use a HV probe and confirm the HV is correct. Your pic looks slightly "zoomed-in / bloomed" to me (i.e. HV too low). Some may say it looks fine.

To me, it needs to be sized down or the HV turned up. Since your comments in another thread notes that the lower voltages are under spec, I would suspect your HV value is also too low (should be 19.5kV). Might want to recheck the actual value.

Also it's good advice to also never allow a color vector to draw lines outside of the screen boundaries. About 0.5-1" away from the edges is best so as to not over-drive the transistors etc. YMMV

MEMORIES FROM 12 YEARS AGO:

I was kind of surprised not one person chimed into my thread yesterday when I asked about the 350vdc on pin 10. But funny you mention the size adjustments. Since I had the monitor out, I adjusted the image some more and brought the sizes down a bit to fit the screen more. Picture is rock solid and looks great. I'm getting a solid 126vdc on pin 8. Maybe I'll grab my HV probe and see what the actual HV reading at anode after Halloween.

 

[VectorCollector]

I was kind of surprised not one person chimed into my thread yesterday when I asked about the 350vdc on pin 10. But funny you mention the size adjustments. Since I had the monitor out, I adjusted the image some more and brought the sizes down a bit to fit the screen more. Picture is rock solid and looks great. I'm getting a solid 126vdc on pin 8. Maybe I'll grab my HV probe and see what the actual HV reading at anode after Halloween.

You do realize there are only three or four "G08/G80 experts" on KLOV, eh? Getting any response would be rare. LOL

 

[jimbodeanny]

You do realize there are only three or four "G80 experts" on KLOV, eh? Getting any response would be rare. LOL

View attachment 858088

Haha that's fair and explains a lot!

 

[KazooBR]

Issue: Outrun G07 monitor was really pink / red. I determined I lost green.

Troubleshooting: After the Fonzie test and wiggling some wires, I pulled it. Fromm flowchart said to check a couple transistors but those were fine.

Resolution: The header pins had a very slight wiggle. I didn't meter out the traces but they seems to be compromised. Removed the solder, scratched the traces to expand the surface area and resoldered.

Fixed!

Here is a good video on G07 troubleshooting from @DeLuSioNaL29. It's super helpful.

 

[SNESNESCUBE64]

From yesterday's workday:
Game: Williams Disco Fever Pin
Symptoms: game resets when both flippers are used at once.
Troubleshooting Steps: I've seen this before. When stuff like this happend it is usually power related. The fact that lights got really dim when I hit both flippers helped confirm that. The cpu board was a rottendog all in one, so I could rule out cpu board issues. Looking at the supply, there were cold solder joints on some of the pins. Reflowed those. While I was in there, I replaced the solenoid capacitor. It is likely unrelated but I figured why not.
Solution: Cold Solder Joints on power supply pcb

Game: Williams Corvette Pinball
Symptoms: Engine Block and two small race cars not moving
Troubleshooting Steps: this one was a tricky one for the wrong reasons. Neither the engine block nor the cars were moving in gameplay or test mode. The power LED was lit on the driver boards for it, so I figured it was getting what it needed. Testing the power in, I measure 20VDC between the power in and earth ground. I usually test on earth ground because it is easy for me to set one meter probe stationary when poking around. This was a mistake. After pulling my hair out and dreading having to make a second trip out to redo the ribbon cables and consulting another technician, I realized that there was a break in the ground line for the motor boards and the driver board. I tracked it down to one of the IDC connectors which resolved the issue. This was really annoying.
Solution: bad ground line on "slave" and motor driver boards

 

[sfspanky]

Blank screen. Burnt connector/fuse bus at F3 on power brick in Pole Position. Installed new fuse bus and finally broke down and soldered the wire to the fuse clip spade.

 

[SNESNESCUBE64]

From this weekend's repairs:

Game: Williams Twilight Zone Pinball
Symptoms: Two issues: GI problems and lower right flipper was sticking
Troubleshooting Steps: The GI problem was easy, just typical Williams WPC burnt connectors on the GI. Replacing the connector and pin header brought it back to full operation with no issues. This machine was swapped out to LEDs so it shouldn't have those issues again. The right flipper sticking was also straight forward. I noticed that it was sometimes catching just a little. Disassembling it revealed two things: The spring for the flipper wasn't as strong as it ought to be and the sleeve had broken on the end. Replacing both of those items resolved the issue.
Solution: GI Problems - replaced burnt connector and pin header. Flipper Problem: - Replaced damaged coil sleeve and spring.

Game: Tempest
Symptoms: Dead
Troubleshooting Steps: I've been itching to work on another Tempissed board. Recently I had picked this one up. Looking at the board, I didn't notice that it was missing the MC1495 at C12, explains part of it. Installing a new one, I got a nice collapsed image.


I had the brightness a bit up on my 6100 so I could power through spotkiller. It was a lot clearer in person than in the image. I saw that I was missing Y movement. I poked around on the scope, comparing the outputs of the analog sections for both X and Y to see what was dead.


Comparing the outputs of C12 and C13, I saw no activity on pins 2 and 14 despite getting an input to 9. Replacing C13 brought back my Y Axis. I've not had great luck with these MC1495s. in general.


I still had goofed up vectors. The X-axis is kinda screwed up altogether. The way the left side line slid over didn't quite make sense for it to be an opamp issue to me. I feel like I would have more distortion instead of incorrect vectors. For giggles I swapped the the DAC at A10. That resolved my vector woes with that.

After that, I noticed that I was missing some sounds. I put it into test mode, it gave me the 'P' error code, meaning that the POKEY at B/C2 on the mathbox was no good. This really sucked, but replacing the POKEY resolved the issue.

Solution: Bad MC1495s at C12 and C13; Bad AM6012 DAC at A10; Bad POKEY at B/C2 (mathbox)

 

[jimbodeanny]

Noticed just recently that the K7000 in @CarrieZ 's Elevator Action had a little bit of a horizontal linearity issue where (more noticeably) the right side would get narrower. Using the TPG showed that there was also a mild version on the left side as well. Per @zenomorp, I knew it was probably due to a lack of the cap on D18. Since this was a 19" and not a 25", throwing the .6200uf 1.6kV cap made the image far too wide as well as too tall to the point that it couldn't be adjusted to correct. So I threw a .3300 cap in there and after changing C38 to a higher value, I had a great image with perfect horizontal linearity.

Game: Elevator Action
Issue: 19" K7000 horizontal linearity off (most noticeably the image squished/narrow towards the right side)
Solution: Added a .3300uf 1600v cap on D18, then changed the width cap C38 to a higher value to compensate

 

[SNESNESCUBE64]

Game: Sinistar
Symptoms: Power supply is constantly activating the crowbar on 5V rail
Troubleshooting Steps: I recently got a Sinistar cabinet that had a switcher hacked in. Unfortunately I want to try to remove that and see what caused the headaches to begin with. I did the standard Williams power supply rebuild, nothing crazy there. But no matter what, I always lose the 5V rail after a few seconds. I figure that the crowbar circuit is becoming active.



Looking at the circuit, it's easy to see that Q4 triggers the SCR at Q1 over a certain voltage threshold. Simple enough. First thing I did was verify all the resistor values in the circuit to make sure that everything was valid. No issues there. Next, I swapped Q1 and Q2 since they are the same part to see if the issue followed, it did not, so it had to either be the Zener ZR1 or Q4. For giggles I pulled Q4 out of circuit to see if the crowbar would trigger. The crowbar did not activate, so that confirmed that it was a triggering issue. I replaced Q4 and hooked it back up, I now have my 5V now without crowbar issues.

Solution: Bad MPSA55 at Q4

 

[zenomorp]

Game: Sinistar
Symptoms: Power supply is constantly activating the crowbar on 5V rail
Troubleshooting Steps: I recently got a Sinistar cabinet that had a switcher hacked in. Unfortunately I want to try to remove that and see what caused the headaches to begin with. I did the standard Williams power supply rebuild, nothing crazy there. But no matter what, I always lose the 5V rail after a few seconds. I figure that the crowbar circuit is becoming active.

View attachment 862065

Looking at the circuit, it's easy to see that Q4 triggers the SCR at Q1 over a certain voltage threshold. Simple enough. First thing I did was verify all the resistor values in the circuit to make sure that everything was valid. No issues there. Next, I swapped Q1 and Q2 since they are the same part to see if the issue followed, it did not, so it had to either be the Zener ZR1 or Q4. For giggles I pulled Q4 out of circuit to see if the crowbar would trigger. The crowbar did not activate, so that confirmed that it was a triggering issue. I replaced Q4 and hooked it back up, I now have my 5V now without crowbar issues.

Solution: Bad MPSA55 at Q4

Great job.

 

[CakeLancelot]

Converted Gravitar: marquee hardware was missing when I bought it. Installed a fixture bought from a member here on KLOV, then new starter and bulb, lastly wired it all up - it works!

Next I am going to see if any of the original art is still present. The cabinet had black melamine installed on both sides, I've already taken off one side, going to try a few different methods to get rid of the gray primer and contact cement. Worst case, it's not salvageable, and I'll have to sand it down to bare wood and buy new side art.

Xevious: Did a general cleaning of all the hardware. Still waiting on a logic probe so I can better troubleshoot the PCB - right now it displays no picture.

 

[terrorinstinct]

Game: Rampage
Issue: Sticks are stuck or sluggish
Repair: Pulling up on the stick made it move freely so I looked up the markings on the base plate and stumbled across the Monroe stick thread. The sticks hadn't been cleaned or lubed in 40 years, I had to double check to confirm there were no O-rings that had disintegrated the grease had degraded so much. Some of the ball bearings had minor mushrooming but that was declared a future problem. After a degreaser soak and a lot of scraping and swearing I was able to get the gunk off and the sticks now work great after some white lithium grease.

 

[SNESNESCUBE64]

Game: Sega Head On 2 (Slimline/VIC Dual PCB)
Symptoms: Accelerator button always pushed in
Troubleshooting Steps: This was a pretty straight forward repair. When troubleshooting input stuff like this, you will usually have one of 3 failure points: Cold solder joints on the pin headers/harness problems, open or shorted pullup resistor, bad input buffer IC. Checking to see if there is a pullup to 5V, I could see that it was REALLY low, some 200 ohms instead of 2.2k. That gave me a hint that perhaps the buffer was pulling it down. Looking at the schematics, the input for the accelerator button is pin 57, which goes to U44.

For giggles I just pulled U44 since I know I have those in stock. Found the culprit!


After replacing U44, the accelerator button worked as it should. Game seems to be functional, I do not have the sound board so I cannot test, but the only complaint was 1P accelerate button.



Solution: Replaced bad 74LS253 at U44

 

[lilypad19]

I like the monitor box and power switch - nice work.