A couple of Pole Position II repair logs..

lilypad19

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Had a few of these lately - this one was sent in labeled "DEAD"

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It visually had a number of issues - but the edge connectors were in reasonable condition. I removed all the socketed chips and verified all of the EPROMS on my tester. PP tests a handful of them on the CPU board - but none of them on the video board.

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I few of the caps were busted or just completely missing - video C4 & C17, cpu C56. Replaced them. After cleaning chips, verifying ROMs and repairing the caps and a few other small items.


Once it was all back together - getting a board set to boot is the hardest part. Here we get through almost all of the boot process before it resets and starts over. There was no 'crash' sound which is standard on PP before the final screen.. That was part of the clue. On the CPU board there are 3 Namco customs, the 51xx, 52xx and 53xx. Each are involved with sounds and voice etc. I swapped some in from a known working board and determined the 51xx was bad. It had failed in such a way that it was preventing the completion of the boot sequence.

Once I got past that - there was plenty more to do. The game now booted into diag mode and reported the 6116 RAM@3F was bad. Replaced that..

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Once the game is running, it is a matter of hunting down all of the glitches. Cars and signs had were messed up colors. Tracked this down to the PROM@12H (a known common failure point) to get them working properly again. While I was looking for the issue - I noticed a wrong RAM was used @10F. These are supposed to be high speed 2149 RAM. As some point someone replaced it with a 2114 RAM. The are pin compatible, but not as fast. Since they are part of the color outputs - I replaced it (which turns out caused an issue a bit later.. stay tuned)

Now that the cars and signs had proper colors.. Another graphics glitch revealed itself..

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This interleaving showed itself on the logo and on the cars at certain points.. they would phase in and out depending on car rotation and position. It certainly had the look of a counter issue..

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The 74S161@10H had been socketed and replaced in the past - but it seemed to be bad again. Replacing it corrected the graphics interleaving. While doing some testing, the boards showed RAM22 had died (on the video board..) except it was fine.. and the 3rd CPU would not boot.

On the CPU board

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These 4 - 10xx customs often cause random errors to the video board. If you can remove, reseat or somehow get the game to boot and fail just by manipulating them - they need sockets. Visually the sockets looked fine, but this style of socket often has a crack in the leg where the pin meets the PCB. This PP set would randomly fail with video board errors.. Replacing the sockets made the game run overnight w/o crashing.

This last part was semi-self inflicted.


Look real close as you pass the yellow sign on the left - you get an interleaved version of it on the right.. This happened in a number of places and even at the end of one of the attract sequences there was an interleaved sign sitting in the middle of a field - where it would not be under normal circumstances.

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It was just noticeable enough to be annoying and was just a brief flash.. Seeing that it was interleaved and it was a sign at least pointed me in the right direction.. Knowing that an interleave like this under normal conditions is RAM related..

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My first thought is was that it was a chip that supported these 2149 color RAM. I pulled the RAM @9F and ran the attract mode and got regular road signs with missing lines as expected due to the missing ram.. The artifact signs still flashing in for an instant.. Next I put that RAM back and pulled the 2149@10F.. I got the signs with missing lines (as expected again) but NO artifact signs! Nice - the issue was on the 10F side of the circuit. Before I went too much further - I put the known working 9F RAM in the 10F socket.. no artifacts.. Bad RAM? yup.. I replaced the RAM that I had replaced earlier and corrected the issue. Maybe it was too slow? to fast? or just lazy.. But it was causing the interlaced sign artifacts in the wrong spot.

Board works!
 
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Next one..

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This one came in from a buddy who had a PP cab and wanted an original PCB. He'd been looking for a while and finally got one worth fixing. Before I could even power it on I needed to:
  • Repair battery damage area
  • Repair burned up edge connector on the video board (not as common, usually it's the CPU board)
I started with the video board edge connector.

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5v was a mess and had been cratered at some point. Cleaned it out and the used the fiberglass pen to sand out the loose part until it was as solid as you can get it.. Cleaned it all up with alcohol and then filled with UV cured resin. The resin sets in 2 minutes and can be scraped and sanded flush with the PCB.

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Add some copper tape and Liquid Tin to complete the repair. The pics make it look a bit bumpy - but the result is actually very smooth and the same thickness as the original fingers.
 
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The battery damage was not quite as bad as it first looked.

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The ICs has a little surface damage, but seemed pretty solid. All of the resistors, transistors and diodes of the area were in pretty bad shape.

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Removed all of the socketed chips gave the damaged area an etching acid bath and then wash the board, dry with compressed air and use a fiberglass pen to polish up the areas and remove as much battery damage as I can within reason.

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All of the effected components replaced.. I cleaned up a bit more in this area as I noticed it. You can only make this look so good..

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Here is the Z80 socket and the Z8000 socket @3A. Both were in pretty bad shape and got replaced.
 
An interesting item on this set.. IC25 was not a custom chip - but this small PCB instead.. Had not seen this in the past.

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After a couple of false starts with sockets and a few other small issues - the board powered up and booting into diag mode, nice! Interesting item - stepping on the gas also stepped on the brake at the same time. I swapped a few customs around as an initial check.. But that was not the issue.

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The 4066@8K had failed and was the root cause of the issue. Replacing it corrected the problem. Now I had a fully functioning PPII set - great! Ran first 12 hour burn-in test.. It lasted about 3 hours. Boards were stone dead. A little probing - no clock.

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I started at the video board with the crystal is - clock was there. Traced back to the CPU board, clock going into the S161@6N - nothing coming out on Pins 13,14. Replaced it and board booted into diagnostics reporting a RAM22 error. I got a 2 for 1 failure. Replaced the RAM@7K on the video board.

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Board works!
 
An interesting item on this set.. IC25 was not a custom chip - but this small PCB instead.. Had not seen this in the past.

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Is it possible to reverse engineer it? 😇
 
Did you liquid tin the acid repair? How did that turn out?

I'm trying to get my green solder mask paint to look decent on repairs like this. If not, I may abandon that and just go liquid tin.
 
Is it possible to reverse engineer it? 😇
I'm sure it can be.. But there is a good workaround for IC25.
There is a 2 ROM set:
176-V3.3L
177-V3.4L

That you can replace the 2 originals and it eliminates the need for IC25.. I'm not sure how to dump the PAL.. etc..
 
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Did you liquid tin the acid repair? How did that turn out?

I'm trying to get my green solder mask paint to look decent on repairs like this. If not, I may abandon that and just go liquid tin.
Blotchy copper colored areas or blotchy silver colored areas.. It is a bit of a tossup.. I've done it with the liquid tin and without. Neither looks great and in this case - not sure anything is really getting protected.. Unlike edge connectors were the copper is used for electrical contact.. I think the tin helps there (well.. in my opinion)
In this case, no tin saved a wash /dry step..
 
Blotchy copper colored areas or blotchy silver colored areas.. It is a bit of a tossup.. I've done it with the liquid tin and without. Neither looks great and in this case - not sure anything is really getting protected.. Unlike edge connectors were the copper is used for electrical contact.. I think the tin helps there (well.. in my opinion)
In this case, no tin saved a wash /dry step..
The tin corrodes resistive much slower than the copper.
 
Pole boards can drive one to drink, that's for sure. lol

I worked on one a few days ago that had white noise in the audio when the sound system was enabled. I must have messed with it for 2-3 hours until I moved on to something else.

Then I remembered, 136014.117 is part of the damn audio circuit. Sure enough, it was bad. lol

My next pile of fun is a Pole II that will randomly start whining about RAM 29 being bad, only it's not. As @lilypad19 described above, random RAM issues are often caused by the 10xx's on the CPU board. NOT THIS TIME. ugh. I need to change the socket to see if that fixes it.

Hey @lilypad19, I find myself in need of a 52xx. I dont suppose you have one that you would be willing to sell do you?
 
I'm not familiar with liquid tin. Why would you use it vs. tinning the copper with solder? In places where you are concerned with lifting a trace?
 
I'm not familiar with liquid tin. Why would you use it vs. tinning the copper with solder? In places where you are concerned with lifting a trace?
It is very thin so it works great on the copper tape for edge finger repairs. You've seen globbed-up solder repaired edge fingers right? Not ideal.

It also doesn't use heat so that could be a plus in some situations.

It is also a bit expensive and hazardous so you need to be careful with it. You can apply it with a cotton swab and only takes a moment or two to adhere.
 
@gamefixer Yea - I just sold my last 51xx, I don't have the others.. There is a guy here starting to repro the Namco's again.. I hope he gets to these..

Liquid Tin - agree with @KazooBR. Coating with solder I didn't care for. It also helps on existing fingers where the copper is starting to show through. It cleans up the edge nicely.. I bottle will last forever if you don't spill it..
 
I've got a lot of parts in my stash in Texass.... Its just a matter of getting there to get them back here.

I probably have 10 of the 52xx's there. lol
 
Any recommendations on brand or price range? I see a bottles for $20 and $37 on Amazon (and much more expensive ones)
Lilypad has a link to lots of useful stuff, see it here …..
 
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