faulty Quadra 650 Mainboard ...

[franklyn]

I buy a faulty Q650 Mainboard and Test it ...

The error occurs in almost 90% of all programs started, including a Mac OS installer. There must be a hardware defect on the motherboard. The board is clean and looks flawless.

 

[zigzagjoe]

Looks to me like you've got a LC CPU on a Quadra 650 (not Centris) board. Quadra 650 configuration assumes a FPU will always be present and thus any SANE traps will catastrophically fail because they use the FPU which causes just about everything to throw a trap like that. Ran into that with the 68060 project.

If you set the resistors to the Centris 650 configuration it should resolve that. Or just install a full 040.

 

[franklyn]

Yes I install a LC CPU from my Performa 475 I have left over.

I install a full 040 and see ...

 

[franklyn]

It works better but Mac OS 7.6 and 8.0 Installer terminates with an error, and upon rebooting, a "sad mac" message appears. The computer only boots up fine with a CD image.

TattleTech start up with the "error 3" ...

... System Bootup
0000000F
00000028

 

[franklyn]

I initially thought it was due to the RAM, which consisted of two EDO SIMM modules. However, the memory test showed no problems. I also tried two 8MB FPM SIMM modules, but without any improvement.

The system installers, whether for 7.5.3 or 7.6, all hang after two-thirds of the installation without any error message ...

I run the Norton Disk Doctor to check the BlueSCSI HDD with no errors.

 

[franklyn]

Suddenly the Mainboard works, which is annoying when it doesn't work and then suddenly does, and you can't find any error to fix. I installed System 7.1 and System 7.6 for testing purposes without any problems. I'm using two 32MB SIMM modules and two 16MB SIMM modules, all EDO, without any issues. I heard that EDO can also do FPM mode? I'm also using two 256KB VRAM SIMM modules from an LC with a 100ns printed speed, and they work without any problems.

 

[franklyn]

I put the Mainboard in my Quadra 700 case ...