Joust cocktail displaying ram error 31.

you really want to know?

it can be about 70 different things. I require more information. are you using the original linear power supply? are fuses blown on it? are you using a switcher? do you have broken wires? what are you seeing on the screen?

coming in asking about a 1-3-1 error on a Williams game and just asking what could be wrong with no other information or photographs will yield limited results.

the 4116 ram that these games use are tri-voltage, they require +5V, +12V, and -5V to operate. if you had no +5V, you wouldn't be seeing the 1-3-1 error, but if the other lines aren't making it to the MPU, the entire ram section of the game won't operate and the power on self test will just say the first ram (ram 31) is bad. if you have a 1-3-1 error and you're seeing a janky rug pattern, then it's probably a bad 74153 multiplexer.

if you're not adept in working on these sort of things then you may require outside help. but let's figure out what the root cause of the problem is first before spitballing. I wasn't exaggerating about the 70 different things. (ask me how I know)
 
It is giving a good rug pattern and going into test mode where it is giving ram error 31. It has a switching power supply installed by a previous owner and the fuses are good. I am getting a clean 4.9 volts out of the power supply. the linear power supply is unplugged as it needs to be rebuilt, so I'm not getting any general illumination at the moment.
 
you really want to know?

it can be about 70 different things. I require more information. are you using the original linear power supply? are fuses blown on it? are you using a switcher? do you have broken wires? what are you seeing on the screen?

coming in asking about a 1-3-1 error on a Williams game and just asking what could be wrong with no other information or photographs will yield limited results.

the 4116 ram that these games use are tri-voltage, they require +5V, +12V, and -5V to operate. if you had no +5V, you wouldn't be seeing the 1-3-1 error, but if the other lines aren't making it to the MPU, the entire ram section of the game won't operate and the power on self test will just say the first ram (ram 31) is bad. if you have a 1-3-1 error and you're seeing a janky rug pattern, then it's probably a bad 74153 multiplexer.

if you're not adept in working on these sort of things then you may require outside help. but let's figure out what the root cause of the problem is first before spitballing. I wasn't exaggerating about the 70 different things. (ask me how I know)
well, now it is giving ram error 32.
 
the actual ram 31 was bad? you should play the lottery LOL

there's nothing wrong with 4116 ram, contrary to what the 4164 pushers say. 4164 ram isn't even that good for these, 41256 is better. both require board modifications to run.
 
Arbitrarily replacing your RAM chips probably won't help. Whenever I'm debugging a random ram error issue on a customers Williams board, if the voltage at the ICs is good, the next step is usually to replace the three data latches (ls373s) for the ram banks, as these have been failing more often, and can be intermittent as well.
 
Arbitrarily replacing your RAM chips probably won't help. Whenever I'm debugging a random ram error issue on a customers Williams board, if the voltage at the ICs is good, the next step is usually to replace the three data latches (ls373s) for the ram banks, as these have been failing more often, and can be intermittent as well.
I think my process with those was probing the data in/outs at the parallel buffers, then go back to the ram they're supposed to go to. if something is getting lost at the buffers then they're assuredly bad. I've had battery leak boards where those got demolished from the outgassing and it leaks up from the legs into the chip. maybe 2 times total the 74245 CPU data buffer was at fault. I should have a picture somewhere from where the chip broke in half when I taking it out after desoldering. good times
 
I think my process with those was probing the data in/outs at the parallel buffers, then go back to the ram they're supposed to go to. if something is getting lost at the buffers then they're assuredly bad. I've had battery leak boards where those got demolished from the outgassing and it leaks up from the legs into the chip. maybe 2 times total the 74245 CPU data buffer was at fault. I should have a picture somewhere from where the chip broke in half when I taking it out after desoldering. good times
I had a shop Williams board I was using earlier this week to debug a customer's Sinistar sound board. Stupid thing booted up to 1-3-1 or 1-2-1, then within a few seconds the RAM error would clear. Did this every time I powered up. Got tired of seeing the error, so I swapped the three LS373s and haven't had a RAM error since. Yes, the corrosion can do some weird things sometimes especially when the corrosion creeps up inside on the IC.
 
I had a shop Williams board I was using earlier this week to debug a customer's Sinistar sound board. Stupid thing booted up to 1-3-1 or 1-2-1, then within a few seconds the RAM error would clear. Did this every time I powered up. Got tired of seeing the error, so I swapped the three LS373s and haven't had a RAM error since. Yes, the corrosion can do some weird things sometimes especially when the corrosion creeps up inside on the IC.
I bought a Defender MPU from Bill Burger back in 2015 and it would boot to ram error 11... after observing said 74374 buffer for bank 1 it appeared some traces just dissolved? fix that, then ram error 21... same thing on the bank 2 buffer. then it worked. I didn't know the POST order then or really much of anything of what I was doing, but it worked then. LOL bizarre part was it had no battery leak.

74373s being "transparent" data latches I think they probe differently, but if you find any opens at the data pins of the rams and they have continuity back to the buffers, then the buffers are bad.
 
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