Hello everyone,
I have a LC575 logic board that plays startup chime but shows black screen and immediately plays crash chime.
I have washed the board twice, there is no visible trace damages. I also desoldered MEMCjr and cleaned underneath it and soldered it back. Re-flowed all other chips pins.
Checked continuity between CLUT and MEMCjr with no issues.
To rule out DRAM, I removed all DRAM from board and used a RAM stick same issue.
To rule out Cuda/Egret issues, I pressed command+power on keyboard and it plays the crash chime again.
I am thinking of checking underneath the DFAC-II or its pins, also checking if ROMs are ok; I might have TL866 adapters for SOJ ROM chips.
I appreciate any hints or advice for next steps. I wish there was some diagnostic software or ROM that could tell us at what stage of boot up the computer crashes, maybe it helps narrowing down the culprit.
I have a LC575 logic board that plays startup chime but shows black screen and immediately plays crash chime.
I have washed the board twice, there is no visible trace damages. I also desoldered MEMCjr and cleaned underneath it and soldered it back. Re-flowed all other chips pins.
Checked continuity between CLUT and MEMCjr with no issues.
To rule out DRAM, I removed all DRAM from board and used a RAM stick same issue.
To rule out Cuda/Egret issues, I pressed command+power on keyboard and it plays the crash chime again.
I am thinking of checking underneath the DFAC-II or its pins, also checking if ROMs are ok; I might have TL866 adapters for SOJ ROM chips.
I appreciate any hints or advice for next steps. I wish there was some diagnostic software or ROM that could tell us at what stage of boot up the computer crashes, maybe it helps narrowing down the culprit.