PCFreek
Experienced Member
Oh boy do I feel like a noob asking a question about such a well documented error... I just want to make sure that I am not missing something obvious.
I have another early 16-64kb MB from an IBM 5150 that was dead. The Supersoft Diagnostic ROM diagnosed a faulty 8237 which I replaced. It now powers up. It will run for a minute or 2 before it gets a Parity Check 1 Error (the fact that it runs a couple of minutes indicates a thermal failure?). The Supersoft ROM gives the RAM error address as 5040. I have replaced socketed RAM until I am blue in the face and it did not help. I have since removed all socketed RAM and have only Bank 0 populated. I have set SW1 and SW2 accordingly (SW1: 3,4 on... SW2: 1,2,3,4 all on) and I still get the Parity Check 1 error with a 57000671 ROM installed. Using SuperSoft Diagnostics to locate RAM issues is useless without all 4 banks populated, so I have not gone back to that. The 5150 gives no error code prior to Parity Check 1 as the error occurs while it is running. I can even boot to DOS before the error pops up.
Any ideas? I now have a Pace soldering/desoldering station and can switch out chips with ease. I honestly don't know how I ever lived without it! I will sooner or later be revisiting some of my other threads that I never finished now that I can desolder like a pro. I pulled the 8237 chip in less than 5 minutes and it popped right out without sticking when I was done. Amazing!
I have plenty of RAM chips and can swap out Bank 0 if necessary. Unfortunately, my replacement RAM is not a proper date code for this board so I would like to avoid that if the error may lie somewhere else. I have piggy-backed all bank 0 RAM with no success. I understand that piggy-backing will not correct all RAM failures. I have replacements for all RAM related chips (LS245, LS280N, etc...) if it could likely be a problem elsewhere.
thanks!
I have another early 16-64kb MB from an IBM 5150 that was dead. The Supersoft Diagnostic ROM diagnosed a faulty 8237 which I replaced. It now powers up. It will run for a minute or 2 before it gets a Parity Check 1 Error (the fact that it runs a couple of minutes indicates a thermal failure?). The Supersoft ROM gives the RAM error address as 5040. I have replaced socketed RAM until I am blue in the face and it did not help. I have since removed all socketed RAM and have only Bank 0 populated. I have set SW1 and SW2 accordingly (SW1: 3,4 on... SW2: 1,2,3,4 all on) and I still get the Parity Check 1 error with a 57000671 ROM installed. Using SuperSoft Diagnostics to locate RAM issues is useless without all 4 banks populated, so I have not gone back to that. The 5150 gives no error code prior to Parity Check 1 as the error occurs while it is running. I can even boot to DOS before the error pops up.
Any ideas? I now have a Pace soldering/desoldering station and can switch out chips with ease. I honestly don't know how I ever lived without it! I will sooner or later be revisiting some of my other threads that I never finished now that I can desolder like a pro. I pulled the 8237 chip in less than 5 minutes and it popped right out without sticking when I was done. Amazing!
I have plenty of RAM chips and can swap out Bank 0 if necessary. Unfortunately, my replacement RAM is not a proper date code for this board so I would like to avoid that if the error may lie somewhere else. I have piggy-backed all bank 0 RAM with no success. I understand that piggy-backing will not correct all RAM failures. I have replacements for all RAM related chips (LS245, LS280N, etc...) if it could likely be a problem elsewhere.
thanks!