Blank Screen , Startup Chime but no Boot. Bad CPU or Logic?

Hello everyone,

this is about the same PowerMac G4 MDD I asked about before here .. 867 DP .

I did some diagnosing today. This is what I found.

Power On :

Chime sounds, fans go, harddrive on the ATA100 won't spin up when on all other ATA channels it does spin up. Screen remains black. Graphics card is working, tested in other Powermac. No keyboard recognition (caps lock led does noch light up). CUDA / PMU reset performed couple of times, removed the battery for 24h. No change.

With the CPU removed it wont even get to get the fans moving or chime up.

After some time in this state after chime and fans going CPU heat-sink is warm. As are graphics card, memory, some chips on the board.

Conclusion :

Either CPU and/or LogicBoard are bad.

How can I determine which one to replace?

Best regards Jan.

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Hello again!

It was a CPU issue. I put a new CPU card in and the MDD came back to life!

Thanks for reading and contributing.

Ciao, Jan.


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it sound like the logic board is not working like it should work.. i think isthelogic board, and it migth not be the cpu.but howthsithishappen, did it got hit by ligthing?? or u stop using it, for a while

logic board


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Hello osvaldo,

Thanks for your answer, it came in like this. I ordered a new Logicboard. I'll get back with the results when replaced.

Thanks and best regards,




After receiving and installing a new board (1445-a) the issue persists.

Should be the CPU then. When I get a new CPU I report back with results.

Or are there other possibilities e.g. power supply ?

Regards Jan.


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Jan Bernert crwdns2893898:0crwdne2893898:0

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