the xt guy
Experienced Member
I've got this 5150 motherboard that when booted up, gives me this POST error code:
1051 201
I know that 201 signifies a memory error. I pulled all the socketed RAM chips in memory banks 1, 2 and 3 and reset the switch blocks to tell the MB that there is only 64K of RAM onboard, in bank 0.
Unfortunately, I still get the same error code.
As you probably know, in the 5150 MB, the first bank of RAM (bank 0) is soldered directly to the MB, the other 3 banks (1, 2 and 3) are socketed.
I have also read that the first 4 numbers of the error code tell the bank number and also the location (in hex?) of the bad chip. Apparently, 0 is the bank number, 51 is a code for the location of the bad chip. A few months ago, I stumbled across a website that detailed some of this info. Of course, I did not bookmark it and now cannot find the webpage.
Even before attempting to unsolder the defective RAM chip, I would have to know which chip it was, as unsoldering the chip would not be easy and there is always the possibility of damaging something. I wouldn't want to unsolder the wrong chip and discover all my effort was for nothing.
If it were a 16-64kb model, it definitely would be worth attempting to save but it is the more common 64-256kb. model.
My 'Upgrading and Repairing PC's' book by Meuller says that IBM, back in the days when they repaired these systems, would recommend replacing the 5150 MB instead of repairing it.
On the other hand, I really do hate to toss out this MB because of one defective generic RAM chip.
1051 201
I know that 201 signifies a memory error. I pulled all the socketed RAM chips in memory banks 1, 2 and 3 and reset the switch blocks to tell the MB that there is only 64K of RAM onboard, in bank 0.
Unfortunately, I still get the same error code.
As you probably know, in the 5150 MB, the first bank of RAM (bank 0) is soldered directly to the MB, the other 3 banks (1, 2 and 3) are socketed.
I have also read that the first 4 numbers of the error code tell the bank number and also the location (in hex?) of the bad chip. Apparently, 0 is the bank number, 51 is a code for the location of the bad chip. A few months ago, I stumbled across a website that detailed some of this info. Of course, I did not bookmark it and now cannot find the webpage.
Even before attempting to unsolder the defective RAM chip, I would have to know which chip it was, as unsoldering the chip would not be easy and there is always the possibility of damaging something. I wouldn't want to unsolder the wrong chip and discover all my effort was for nothing.
If it were a 16-64kb model, it definitely would be worth attempting to save but it is the more common 64-256kb. model.
My 'Upgrading and Repairing PC's' book by Meuller says that IBM, back in the days when they repaired these systems, would recommend replacing the 5150 MB instead of repairing it.
On the other hand, I really do hate to toss out this MB because of one defective generic RAM chip.