Compaq Portable RAM error

VintageVic

New Member
Jan 16, 2020
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I am working on my first restoration project, a Compaq Portable (not my first choice, but it was a steal!) with 256k total in RAM. I have replaced all the electrolytic capacitors in the power supply, and the CRT, And have replaced the foam pads in the keyboard. However, every time I start it, it gives me the error code 0020 201. It has banks 0-3 filled with 64kx1 RAM chips, so I think it is U45, however I can't for the life of me find it! I have made sure that all the connections are good, and all the ram chips have been socketed. Any help would be great!
 

Grumgi

New Member
Jan 23, 2020
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You've probably done this, but just in case you haven't try replacing the RAM modules and testing each one of them socket by socket and see if you get a differing result.

Sorry I can't offer much advice outside of that, vintage laptops are completely out of my scope of knowledge.
 

VintageVic

New Member
Jan 16, 2020
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Good idea! I should be trying that. It's just such a pain to put the motherboard back in after each test. I may mod a new power supply so I can test outside of the case, just need to find the pinout. I have a Commodore 64 that came in through ebay that I can hopefully use to test the RAM chips. Only problem is that it has no sockets, and only ceramic chips, which I'm not sure I want to mess with
 

VintageVic

New Member
Jan 16, 2020
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I've tried the arduino route, but I've never gotten it to work. I thought the C64 would be my best bet because it uses the same 4164 (also known as 8264) chips