What fixed your game today / general repair log

[wugly]

I like how quickly this morphed into me trying to trick Jason into repairing a board that's not broken!

its not you, We all have been taken advantage of by someone on ebay at one time or another and just get cynical every once in awhile. There are many threads on this forum where someone did something disreputable.

 

[lilypad19]

Worked on a Tempest:



Reporting graphics issues. Initial inspection and chip cleaning happened at the lake.. It had some work done in the past with a mix of adjustment pots in the analog section.

After cleaning and Dexoit, board ran but the graphics were in bad shape..

At this point I had not replaced the pots in the analog section (which I always do on boards with the the stand up analog pots).. This corrected all of the graphics issues. The last issue I've known existed, but had never seen in person...

Updating to R3 ROM set fixes this.. It is a function of an early deflection board and ROMs. I'm using a different bench monitor in this case.

Board works!

 

[Jmari98]

US dedicated time crisis 1

Gun had no recoil, replaced sla4060 on the gun drive PCB board and cleaned it up with some 91% alcohol.
Recoil started working perfectly.

Monitor was all messed up and couldn't find much info on my sharp image chassis. Not sure there's even a cap kit for it lol. so i sent it out for repair.

50% of the monitor was covered in random colors and brightness/contrast was way out of whack. Did some adjusting, degaussed it with my coil like 5 times with maybe a 20% improvement.

out of ideas i grabbed the yoke, pushed up with more force than i thought I'd have needed to and it popped into place showing me a perfect picture

One of my more involved fixes, just started diving into repairing my own stuff recently so i'm happy.

 

[callanbrown]

Game: Mr. Goemon (Konami, 1986)
Symptom: Reset loop
Solution:

Spoiler: Click if you don't want to watch the video

Bad 74LS138 that was running the chip enables on the program ROMs.

 

[SNESNESCUBE64]

Game: Taito Warp-1
Symptoms: Sections of the screen not displaying. Missing a section in upper play field and bottom


Troubleshooting steps: I had no schematics, so it was a shit ton of guessing and seeing what happened! I poked a lot of signals in what I believed to be the color section just to see if anything didn't make sense. I got to IC45 (74LS08) and noticed that pin 3 was stuck low despite having what looked like valid inputs on the scope. Piggybacking a new one showed gave me a couple lines on the bottom back, so I figured it was worth trying a new one. Pulling it, my chip tester said that it was working. However, pushing in a new 74LS08 (not soldering it in) brought back sections. So I installed a new 74LS08, which fixed the issue.

Solution: Replaced bad 74LS08 @ IC45

 

[alfonzotan]

I have a franken-Defender Multi-Williams with a JROK and a Moon Patrol stack mated to a 2-way JAMMA switcher. I'd originally been using one of the old Lupine Systems switchers, which were built for the infamous PC Amusements bootleg cabs back in the early 2000's (I recycled it out of a cab I rescued from a trash dock many years ago). Worked great for several years, but I started having power issues with both boards in the last few months. After a few fits and starts, including a complete rebuild of the JAMMA wiring harness (which I do not regret; the custom harness I shelled out for when I built up the cab turned out to be pretty crappy in the power section), I finally realized that the fundamental issue (and source of that awful burned component smell) was the switcher.

Fortunately neither of the game boards turned out to be damaged, so I picked up a @RiddledTV 2-way switch and started rearranging things. Got everything working today (don't forget to link the monitor sync from the P-post on the harness directly to the monitor, kids). Only regret is that the Riddled board does not supply constant power to both sides simultaneously, but OTOH, for all I know, all the extra current required for that was the original source of my problems anyway, so mox nix, as they say.

Nice to have this one back in the lineup and 100% again.

 

[jacklick]

so mox nix, as they say.

I have to be that guy...I think you meant macht nichts, which is german, but I love the share and mox nix.

edit>> I guess I am the jacklick mox nix is some american slang.

 

[alfonzotan]

I have to be that guy...I think you meant macht nichts, which is german, but I love the share and mox nix.

edit>> I guess I am the jacklick mox nix is some american slang.

I spent about 20 years working with fighter pilots, they used that a lot. I never asked any of them to spell it for me, though...

 

[mwiggett]

Not much of a repair but I had an extra Centipede board for about a year on a shelf that I bought not working. Finally decided to take a look at it. It was missing one ROM, both objects ROM's, high score chip, a capacitor, a resistor, and the red LED power light. I replaced all missing components and to my surprise it actually works. I was really expecting it to need more work.

 

[Anthony605]

I had a graphics issue with the "city" on the second level of Moon Patrol. It turned out that ROM 3H on the last board of the board set needed to be cleaned and re-seated. Here is the repair thread... https://forums.arcade-museum.com/threads/moon-patrol-graphics-issue-level-2.555213/#post-5010690

 

[parism]

My boys complained that the Wonderboy game is "messed up, rolling up and down!". I knew the issue immediately, vertical hold:



Quick adjustment, basically half a hair turn and we were up and running again…



Easy fix.

p

 

[ArcadeTechGW]

Game: Exidy2 Tail Gunner II
Symptom: no audio
Troubleshooting steps:
Reviewed manual
Pulled audio board.

Replaced Q6 and Q7.
Installed audio board. Still silent

Removed the ribbon cable. Noted that one side of the ribbon cable was "smudged" black and that the ribbon cable was installed for the audio board with the smudge on the wrong side.
Rang out each pin with an ohm meter. The last pin ran >1 ohm, so I flipped the cable.

Powered on game, sound is back.

 

[SNESNESCUBE64]

Game: Nintendo Space Demon
Symptoms: Graphic nonsense


Troubleshooting Steps: Looking at the space demon boardset, I noticed that there were two PROMs on the video board. I went to go swap them to see if maybe one of the PROMs was dead or something. I know that they aren't the same but I figured that it would have been close enough for testing purposes. Going to swap them, I noticed that on Space Demon the 27S00 RAM and 3N PROM were swapped. Putting these chips in the proper position resolved this issue.


Solution: Ensure that 27S00 RAM and 3N PROM are in the correct place.

 

[obitus1990]

Picked up a PacMan cabaret...game was dead, monitor didn't look right. Recapped the monitor, got it working, white screen present. Pulled the game board and tested it on my JAMMA rig, works 100%. In this case...it was just a fuse! Found a blown 1A fuse on the 12V line from the transformer in the bottom of the cabinet. Game now works 100%.

 

[SNESNESCUBE64]

From yesterday's day of work:

Game: Star Trek the next generation pinball
Symptoms: Right cannon will not always autohome
Troubleshooting Steps: First thing I checked was the homing switch, the cannon test shows both limit switches working just fine. For giggles I took the shell off the cannon, I noticed electrical tape on some of the wires. Turns out one of the wires broke. This is when I learned that part of the homing process upon bootup involves the optos. It makes sense, if the optos aren't working reliably, the cannon won't be able to fire.
Solution: Broken wire fixed

Game: Bally Strikes and Spares pinball
Symptoms: Dead, only signs of life is GI
Troubleshooting Steps: Checked 5V, nothing. No fuses popped. Re-seated the power inputs to the game, saw a little bit of sparking. Game booted up. Turns out, that like half of the other Bally and Stern games of the time, it has bad pins on many of it's connectors. So after a ton of work repining it, the game booted up reliably.
Solution: Connectors needed repining

Game: Six Million Dollar Man Pinball
Symptoms: Player 5 display out
Troubleshooting Steps: Pulled out the display to look at the pin header. These are notorious for having cold solder joints, which will cause these issues. This one was no different...
Solution: Reflowed cold solder joints

 

[Scott C]

Game: Atari Dig Dug - Revision B PCB
Symptoms: Game plays and sounds fine except points are incorrectly displaying, such as when Pooka and Fygar are exploded. The issue was the same on the title screen, during the demo, and during game play.
Troubleshooting Steps: All of the customs were clean and this points issue had that feel of being EPROM / sprite related despite the game always passing the ROM test at power up. Plus, the incorrectly displayed points shown were always the same. This led me to the row 5 EPROMs. In performing a visual review, I found that pin seven (7) of the 5C EPROM (Atari 117 ROM) was broken, thus making no contact with the socket. Replacing with another freshly burned 2532 and the issue was gone.
Solution: Replace the 2542 EPROM at 5C.

This was kind of a goofy symptom and fix, so I wanted to share.

Scott C.

 

[SNESNESCUBE64]

Off to a good start today, Head On N has been down for a couple months now so I finally got around to it.

Game: Nintendo Head On N
Symptoms: Garbage on screen, no boot
Troubleshooting Steps: I am kicking myself in the butt for this one. I ignored my own advice of "always rebuild these pre-Radarscope Nintendo supplies, they are terrible and will get ya". So it did what they do: take out the board. 3 out of 4 of my pre-RS supplies have all failed in a dumb way now. Testing the voltages, I didn't notice anything absurd, but there was some noise on the 5V and 12V rail so I figure it is something with that. So I did a recap and replaced the bridge rectifiers. Both of those are always a problem for some reason.

After rebuilding the supply, still no boot. So I pulled the board out and did a feel test on the 4027 DRAMs. The RAM at E5 was much hotter than the rest, so I did a guess and replaced it. This was my trainwreck board I got on yahoo auctions for $30, so I already had the RAM socketed, so no harm no foul. That ended up being my issue. I really need to order more 4027s, these are always failing on me. Between gorf and this I've burned through my stock.

Solution: Bad 4027 DRAM at 5E

 

[SNESNESCUBE64]

I had a bad week with Head On N. Guess what happened: power supply failed and decided 16V was better than 12V. It conveniently took out every single 4027 DRAM. I said screw it and replaced the power supply with a meanwell and adapter I made so I didn't have to hack up the harness. I am so tired of dealing with those pre-radarscope Nintendo supplies, they aren't great and fail this way. The 12V circuit is the same design as the 5V circuit, so I will no longer be taking risks with these things on my rarer Nintendo games. Anyway, after getting this working I had a little bit of sound issues.

Game: Head On N
Symptoms: Missing dot/bonus sound
Troubleshooting Steps: This was just a little bit tricky, I had to decipher where things were based on the Gremlin schematics since I don't think there are schematics floating around for Head On N. So this is what we got:


I come to find out that the circuit is identical. So it would be easy to kind of figure out what is going on. The 555 in this circuit is at 2B, the 4069 inverter is at 2C. The same exact gates were used in the Head On N board as the gremlin one, so that made it easier. I noticed two things: The outputs are the 4069 were a little noisy and despite getting valid inputs to the 555 it did not make any outputs. Pulling both chips, the 555 tested bad and the 4069 tested fine. I replaced both chips and now I have the sound back. The likely culprit was the 555. Since I got the machine, the dot sound sounded crunchy, so I think the 4069 was partially to blame for that.

Solution: Bad 555 at 2B and not so great 4069 at 2C

 

[SNESNESCUBE64]

Finally getting around to fixing the stuff that is down in the house. Radarscope has been missing its grid for a month now and I've been dreading working on it because it is in an analog section that isn't printed well in the schematics.

Game: Nintendo Radar Scope
Symptoms: Grid is messed up, really dark and sometimes non-existent.
Troubleshooting Steps: This screams analog problem to me. The grid was sometimes there, but sometimes not. I noticed that the blue gradient was a little darker and a little flikery too.



You might be thinking, man that is a bad scan. Nope, the printing of the original copy is just that bad. I know that because I managed to source one. I figured it was one of the quad solidstate switches. I've had terrible luck with them. So I started poking around the 4066s. Getting to 1P, I noticed that there was activity on all of the control lines, which is great. However, one of the pins was stuck despite there being activity (I don't remember which one), meaning that something was a bit wonky with this chip. Pulling the 4066 and putting it on the tester, the tester said that it was functional. I went ahead and replaced it anyway because that is what my gut said. The grid is now back to normal.

Solution: Replaced bad 4066 at 1P

 

[SNESNESCUBE64]

Game: Gremlin Space Firebird
Symptoms: Missing Green
Troubleshooting Steps: well, this was my fault. I had to borrow the g07 chassis for another project, so I put one in that I worked on years ago. It had a cracked neckboard. So I examined my previous repairs. Oops, missed one cracked trace. Fixing the broken trace fixed my issues.
Solution: Fixed broken neck board trace.