Williams joust cpu 131 error

chas010

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I picked up a non-working joust that is displaying the 131 ram/power failure. I have replaced all the 4116 ram and checked the voltages on the ram legs. I then swapped in another cpu board to make sure its not the power supply and or the wiring and the game works great. The seller told me that the game was on during a power outage and when the power came back on the game was dead. What coulda took the brunt of the power surge and cooked on the origional pcb board? I tried swapping out the special chips not sure what next...

Jason
 
What were the voltages on the RAM chips? Were any of them fluctuating?

Next most likely would be the address decode chips on the MPU board.

ken
 
Thanks Ken.

The voltages werent fluctuating, from memory they were -4.91, 4.9x and 11.3. Ill try the address decode chips!

Jason
 
Hey Ken would that be the 4E, 3D, 3E and 4F 74153 chips? sorry for the newb questions.
Jason
 
I replaced the address decode chips and still the same 131 error :) shotgun repairs havent been going good for me lately but hey its still fun.
 
check all the header pins for cold solder joints if you havent already...
the +4.9 volts might be too low for that particular board. i would connect a switcher to the +5V and turn it up to 5.1 or 2 at the most and see if game boots.
 
I picked up a non-working joust that is displaying the 131 ram/power failure. I have replaced all the 4116 ram and checked the voltages on the ram legs. I then swapped in another cpu board to make sure its not the power supply and or the wiring and the game works great. The seller told me that the game was on during a power outage and when the power came back on the game was dead. What coulda took the brunt of the power surge and cooked on the origional pcb board? I tried swapping out the special chips not sure what next...

Jason

Post pic of the rug pattern generated, please?


I have working Joust MPU's....

Saltbreez
 
Check the write enable line for that RAM bank...I don't recall off the top of my head what the reference designator or chip type (or/and..)

It's a 7410 on Joust ic's 4M and4L?
 
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First off, you should start a new thread rather than piggy-backing on someone else's, especially when it's a dead thread.

Secondly, 134 is a RAM error - have you tried replacing that RAM chip?

(Actually, secondly should probably be "Do a search for RAM errors on Joust/Williams games.")
 
Sort of relevant here....

I fixed my 1-3-1 on a robotron/joust by swapping 7410 @ 6I.
 
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