Pole Position Horizontal Lines on Cars and Signs

[TimePiloteer]

Working on another Pole Position 1 set, and stumped with this video pcb issue. There are horizontal lines on all the cars and signs.

I swapped custom 13H, ROM 11N, no dice with known good ones. I piggybacked 74LS161 on all the motion object ones around 9h-10k, with no difference. I did not swap the 2 2149 rams on the video board.

Anyone seen this before?

 

[KaBoom1701]

Run away.... run now.

 

[rmackie6661]

did you ever find the culprit on this i'm having the same issue
on a PP2

 

[TimePiloteer]

Not yet, I plan to give this some more attention this weekend, as some various chips arrived this week.

 

[rmackie6661]

do let us know if you find anything
I have the same thing going on after sanding all the chip legs on the video board

 

[texasmame]

From the manual - this tells you which PROMs, IC or RAM to check for your problem.

 

[rmackie6661]

all cars and signs then it looks like?

 

[texasmame]

all cars and signs then it looks like?

Depends on what they consider "large and small."

I'd clean/reseat the chips associated with the LARGE first then check progress.

 

[TimePiloteer]

I have a different video board with a problem with just the small cars and signs, where they have strange lines through them, but as you approach closer to them and they scale up in size, the lines disappear and look normal. It's pretty strange, but obvious it's a small car/sign issue when you see it.

The pics I posted in this thread always have lines on the cars and signs, no matter if they are far away or close, so it should be related to the All Cars chips. Swapping 13H and 11N though hasn't helped. So now it is desoldering 12H or the 2149 rams, or some buffer chip in the circuit.

 

[texasmame]

I have a different video board with a problem with just the small cars and signs, where they have strange lines through them, but as you approach closer to them and they scale up in size, the lines disappear and look normal. It's pretty strange, but obvious it's a small car/sign issue when you see it.

The pics I posted in this thread always have lines on the cars and signs, no matter if they are far away or close, so it should be related to the All Cars chips. Swapping 13H and 11N though hasn't helped. So now it is desoldering 12H or the 2149 rams, or some buffer chip in the circuit.

Still try cleaning and reseating all the other sign/car associated socketed chips before doing any desoldering. Never know!

 

[TimePiloteer]

This happened to be the 2149 sram at 9F. Replacing this fixed 2 different video boards that had the same issue.

One of my video boards had horizontal blank lines through the entire screen during a game. I cut out and replaced 9F with another one I had, and the lines reduced to just showing on the cars and signs. Suspecting that the replacement was also faulty, I swapped it another 2149, and all the lines went away.

So if you see lines like this, take a look at 9F.

 

[66GTO]

This happened to be the 2149 sram at 9F. Replacing this fixed 2 different video boards that had the same issue.

One of my video boards had horizontal blank lines through the entire screen during a game. I cut out and replaced 9F with another one I had, and the lines reduced to just showing on the cars and signs. Suspecting that the replacement was also faulty, I swapped it another 2149, and all the lines went away.

So if you see lines like this, take a look at 9F.

I had the same issue, and after socketing a new chip at 9F, the problem still existed. What ended up fixing it for me was replacing 10F, same 2149 chip, right next door. @TimePiloteer, thanks for the documentation of the fix, got me to a fix without spending a bunch of time.