Zoo Keeper won't boot

MonsterBash

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So this is my first attempt at a Taito repair...in fact the first Taito game I've owned.

I'm getting 10 1000 ram failure at U17 which seem to the the first RAM that gets addressed(?). Someone replaced all the RAM including 17 which was soldered directly to the board (no socket). I found a bunch of lifted traces at 17 and spent about an hour repairing them last night. I socketed U17 and confirmed proper continuity..obviously installed a new 4116.

I still get the 10 1000 error and the pic below

The machine has a arcade shop switcher. I'm getting proper voltage included 5.05 at the ICs

And to make matters worse I was probing around the board and the power lead from the probe snapped off the 5v and hit the 110 AC on the switcher...that was the end of the probe's life. Gonna order a new one today.

Whatcha think?
 

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So this is my first attempt at a Taito repair...in fact the first Taito game I've owned.

I'm getting 10 1000 ram failure at U17 which seem to the the first RAM that gets addressed(?). Someone replaced all the RAM including 17 which was soldered directly to the board (no socket). I found a bunch of lifted traces at 17 and spent about an hour repairing them last night. I socketed U17 and confirmed proper continuity..obviously installed a new 4116.

I still get the 10 1000 error and the pic below

The machine has a arcade shop switcher. I'm getting proper voltage included 5.05 at the ICs

And to make matters worse I was probing around the board and the power lead from the probe snapped off the 5v and hit the 110 AC on the switcher...that was the end of the probe's life. Gonna order a new one today.

Whatcha think?


I don't know that hardware but if you think it is a ram problem you can usually piggy back a good one on top of a suspect one.
 
I'm thinking it's not a RAM issue. u17 is the first RAM in the first column .

All the other RAMs where socketed except u17. Someone replaced all the RAM including an attempt at 17 which that destroyed the solder pads..traces..etc. I jumper wired a bunch of traces and had the same test results...pin to pin..as the all the other RAM with the probe (before I torched the probe). I'm pretty sure I have the trace issue fixed. I don't think I have a bad RAM. I would assume I have something else going on giving me the RAM error.

I've switched RAM on board from other locations to u17 and get the same error.

Following the traces on the board I have confirmed continuity from every pin on u17 to it's corresponding trace at the next IC (and of course..also confirmed traces that don't end at an IC). I checked these before I install the board after the repair, then pulled the board again and rechecked after the same error



I don't know that hardware but if you think it is a ram problem you can usually piggy back a good one on top of a suspect one.
 
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Hey. I'm trying to follow along and keep score at home on this.
I'm looking at the schematics for the "data processor" board, and U17 isn't a RAM, it's a 74LS138. U15 & U16 are 2114 RAMS...

Is this a case of a typo, or are there more versions of the hardware than what I've got schematics for? (I'm looking at... http://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Zoo Keeper.pdf)
 

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...OK. It looks like you're talking about the video board. It does have a 4116 @ U17 :)

Since the other RAMs are socketed, you might try pulling one of the RAMs in the U10-U16 range, to see if that would generate a different test failure. This might help deteremine if it's an issue specific to that location (bad IC, bad socket, bad trace) or more systemic to that whole block of RAM (bad output latch IC, bad select IC).

You also might carefully check the interconnects between PCBs.

When you get another logic probe, you might check the LS32 @ U49, as it drives the R/W line and the enables the output latch... which you might also probe (LS373 @ U77).
 

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Yeah.. the -5 was at about -4.80... 12v was about 12.20 from what I remember

I did switch RAM around with no changes in the LEDs

On time when I was probing u15 I think I shorted 2 pins in the 4116 and the LEDs changed to report u15 was bad.

Rebooting the game and got the u17 error.

The wiring does look unhacked but the same person that changed the RAMs also installed the switcher so anything is possible. The Video out pinouts were wrong..I had to repin that cable...might be worth a look

Ordering a new probe as I type
 
Thanks John...I knew it was FUBAR when I got it. Sucks not having any tests parts laying around...or in another machines.

Will figure it out eventually
 
Bummer

Man, that sucks that someone soldered all the 4116s to the CPU board.. If they were gonna take that much trouble to do that, they should have upgraded the ram to a faster more stable kind.. You've got a tough one there.. As I've never had to deal with soldered chips on a ZK pcb.. The last post is correct, if you don't have -5 going to the 4116s your going to get an error at the first chip..

I've got a few boards that aren't hacked up, but don't work 100%.. if you get sick of dealing with yours.. I do have a few working ones with battery mods too.. But they aren't cheap.

If you need help, I've got a couple machines and plenty of parts, ps adapters, etc.. Send me a pm..

Good luck!
 
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Ahhh

Only one spot and they wrecked the traces and pads.. Damn..
The biggest issue with these pcbs is finding one without or with low battery acid damage.. Out of 30 or more I own, maybe 5 or less are clean..

It's a good idea to replace all the ribbon cables too.. Lost count on the amount of errors I had, just to finally figure out it was a bad connector or ribbon cable.. Annoying :(

Let me know if I can give you a hand.. I'm only 6 hours away!
 
I'm lucky there...this one doesn't have any battery damage..it got a new 3.6v installed.

Do have a know working PCB for sale?. I wouldn't mind having an extra and it would certainly help with troubleshooting

You can even take the 4116s if ya need them

Only one spot and they wrecked the traces and pads.. Damn..
The biggest issue with these pcbs is finding one without or with low battery acid damage.. Out of 30 or more I own, maybe 5 or less are clean..

It's a good idea to replace all the ribbon cables too.. Lost count on the amount of errors I had, just to finally figure out it was a bad connector or ribbon cable.. Annoying :(

Let me know if I can give you a hand.. I'm only 6 hours away!
 
was this ever solved...i have a similar screen...i know its not my ram since its all been upgraded with new sockets...
 
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