Gateway 2K 386SX Will not post

[bakemono]

Well as expected/feared replacing the P82C206 chip did not resolve the issue. The system still reports "CMOS inoperational. System Halted"

When I disassembled the AMI 286 BIOS I found code that triggers this condition. It writes $AA to the CMOS RAM shutdown status byte (index $0F) and then reads it back to make sure that the data matches. If the data doesn't match it sets bit 14 in BP which causes the error to be displayed later in the diagnostic process.

Not sure how you'd go about troubleshooting this further without a logic analyzer or something. But the message hints at the second chip being faulty or the motherboard has some problem with port I/O

 

[Shadow Lord]

Thanks. I had seen a reference to that issue when I was researching a cause but could not figure out what is exactly going on. I am going ro have to declare this board dead beyond repair by me at this point.

 

[gatewayrepairs1985]

Well as expected/feared replacing the P82C206 chip did not resolve the issue. The system still reports "CMOS inoperational. System Halted"

Hi! Just curious - any more luck on repairing this machine or have you moved on?

 

[Shadow Lord]

I moved on. Got a replacement motherboard that was close followed by an actual retail version of the OEM board used by G2K.

 

[gatewayrepairs1985]

I moved on. Got a replacement motherboard that was close followed by an actual retail version of the OEM board used by G2K.

Ah, I see - glad you were able to find a workaround. Do you still have the Gateway or did you get rid of it?

 

[twolazy]

Having dealt and fixed a ton of corroded motherboards, always follow the ground plane. Some reason it loves to spread across it to rest the motherboard. If you ever get bored and wanna resurrect the old board that is.

 

[Shadow Lord]

Having dealt and fixed a ton of corroded motherboards, always follow the ground plane. Some reason it loves to spread across it to rest the motherboard. If you ever get bored and wanna resurrect the old board that is.

Can you expand on that? I did not find any obvious ground shorts but admittedly electronics is not my area of expertise. Is there be something specific I need to look for? Thank you.

 

[twolazy]

Follow the ground plane under the keyboard connector and/or ram, usually whats closest to the battery, also the first or first couple isa slots... Its spreads fast on those thicker traces. If the bios is near that area, going to have to most likely remove the bios sockets and do some cleaning up traces. All depends whats close and how bad it was. Follow the ground of the battery outward.

 

[Shadow Lord]

Follow the ground plane under the keyboard connector and/or ram, usually whats closest to the battery, also the first or first couple isa slots... Its spreads fast on those thicker traces. If the bios is near that area, going to have to most likely remove the bios sockets and do some cleaning up traces. All depends whats close and how bad it was. Follow the ground of the battery outward.

Thanks. I have the MB around here somewhere. I will take a look at it and post what I find.

 

[gatewayrepairs1985]

Thanks. I have the MB around here somewhere. I will take a look at it and post what I find.

Looking forward to your results! Learning about how to deal with corroded boards is a valuable skill I have to learn!

 

[twolazy]

Its something I'm still learning... First board I ever did I screwed up badly. Took a year or 2 for me to try again, nowdays I'm pretty decent at it. I too would love to hear your results. Maybe next board ill document. I always forget to take pictures on stuff I restore or fix.

Biggest advice I can give is its never going to be perfect again. Dont strive for perfection. Strive for something thats solid and works well. Dont obsess over the board color, or perfect solder joints. Chances are you are not restoring anything super important or that rare. Focus on just making it work. And know when to walk away and take a few mins to clear frustration.

 

[gatewayrepairs1985]

Its something I'm still learning... First board I ever did I screwed up badly. Took a year or 2 for me to try again, nowdays I'm pretty decent at it. I too would love to hear your results. Maybe next board ill document. I always forget to take pictures on stuff I restore or fix.

Biggest advice I can give is its never going to be perfect again. Dont strive for perfection. Strive for something thats solid and works well. Dont obsess over the board color, or perfect solder joints. Chances are you are not restoring anything super important or that rare. Focus on just making it work. And know when to walk away and take a few mins to clear frustration.

That is very wise advice - accepting the fact that perfection isn’t necessary on these boards is a big part of it for me. Like you said, as long as it’s solid and functional that’s what counts!