"ROOT RAM ERROR" on Taito Continental Circuit

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"ROOT RAM ERROR" on Taito Continental Circuit

Hi, I have a continental circuit that boots to a "root ram error" I cleaned the board and re-seated the socketed chips and connectors but no change.

I assume I need to replace some ram chips. Does anyone know which ones??

Thanks!
 

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Hi, I have a continental circuit that boots to a "root ram error" I cleaned the board and re-seated the socketed chips and connectors but no change.

I assume I need to replace some ram chips. Does anyone know which ones??

Thanks!

it is my understanding that with ram, you can determine the bad one by just snapping a god one over top of one piggy back style, and it will start working. Weird huh!
 
it is my understanding that with ram, you can determine the bad one by just snapping a god one over top of one piggy back style, and it will start working. Weird huh!
Not really... The good one simply replaces the missing or bad signal(s). Of course this is only to be used as a troubleshooting method and not as a permanent repair.
 
Thanks for the tips guys. I did order another untested board, in hopes of making one good boardset from the 2.

I'd still like to try to troubleshoot the bad ram chip, but I'm still unsure of where to start on the board or what chips are the " root ram"..,
 
I dont know what ram would point the message, but you´ll find 4 TMM2064 of working ram, as it has 2 68000 cpu´s, 2 rams near of each cpu. Though the best would be to swap cpu bd with the good one and see if the problem is there or in video bd.
 
Got the untested board today and it boots to a scrambled text & symbols :/ I narrowed the problems to the CPU board on both sets. I tried swapping around all of the socketed chips between the boards but they both act the same.

I may attempt to troubleshoot the CPU board that throws the RAM error with the scrambled board.
 
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Not really... The good one simply replaces the missing or bad signal(s). Of course this is only to be used as a troubleshooting method and not as a permanent repair.

When you say "not really," it is confusing people.
 
When you say "not really," it is confusing people.
Sorry, I meant it's not really weird.

necroscope said:
I've come across some boards with this method of repair before..lol..
Yes, so have I. I guess if you're not able to desolder an IC it is preferable to having a non working board, but it's certainly not a very professional repair.
 
Got the untested board today and it boots to a scrambled text & symbols :/ I narrowed the problems to the CPU board on both sets. I tried swapping around all of the socketed chips between the boards but they both act the same.

I may attempt to troubleshoot the CPU board that throws the RAM error with the scrambled board.

Did you try to plug on the RAM ERROR CPU board with video bd of the scrambled bd? I would do that to see if ROOT RAM ERROR comes from video bd..
If you already tried and still showing the same error, you should start replacing rams one by one...
 
Before you do anything..

Is your power supply original? Does it produce the correct voltages? Ram errors can easily pop up when a game is under powered.. Learned that the hard way with Zookeeper and Qix.. Wasted hours changing ram, sockets, etc and all I needed was a good ps..
 
I measured 5.2 V at the switcher...other than that not sure what else to test, still new at these machines.

Also, not sure if the power supply/switcher is original. Someone re-organized where everything goes in the cab, so I wouldn't be surprised if parts were not original. I'll take a picture.
 
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I checked the 5V at the jamma connector, it was around 4.9V. Just for the hell of it I adjusted the 5V pot on the switcher and upped it to 5.1V per my crappy voltmeter. No change in the behavior of the machine.

Attached is a picture of the switcher setup.
 

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