RAM slot causing system not to boot after CPU Upgrade, Mac Pro 1,1

hcs-mac

macrumors newbie
Original poster
I am having a weird issue after I updated the CPU's on my Mac 1,1 to the quad core from the dual cores.
If dimm 1 on the lower RAM board is occupied the system does not boot. The system turns on and the fans turn on as normal however there is no video out put and no chime, the white front LED is as normal. I have tested this with both RAM boards and it does not boot if there is any RAM in Dimm 1 on the lower RAM board. I am not sure what is causing this. I have switched the RAM around on the board and it is always the same Dimm 1 causing the issue. The board works fine with all ram in it, if it's in the top slot.
Could I have damaged or broken a chip while installing the CPU's? I don't think I have bent any pins, I checked that thoroughly before installing the new CPU's. I have replaced many CPU's in the past and never had an issues before.

UPDATED: After doing some tests in the system I realized only the TOP slot is working and detected by the system. I have 32GB over 8 sticks and only 16GB shows up with 7 of the sticks in. I have to have dimm 1 stick removed to get the system to boot. I am not sure what is causing this issue. There is no RAM failure LED's on the boards.
 
Last edited:

Macschrauber

macrumors 6502a
Dec 27, 2015
752
297
Germany
Give the slot a good clean with isopropyl alcohol. Also you might search for smc update to that version of 2.1
 
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Macschrauber

macrumors 6502a
Dec 27, 2015
752
297
Germany
There is a Firmware in the flash rom chip and a firmware in the smc chip. A proper upgrade is upgrading both.
 
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hcs-mac

macrumors newbie
Original poster
There is a Firmware in the flash rom chip and a firmware in the smc chip. A proper upgrade is upgrading both.
I will look into that, I went to downgrade the firmware however it said that that 1,1 does not support the X5365. I was sure it was supported however I would like to make sure. I have cleaned the RAM slot out with isopropyl alcohol and there is still not a change, when the RAM is in the lower slow there is a solid white light on the front.
 
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Macschrauber

macrumors 6502a
Dec 27, 2015
752
297
Germany
Next cause could be a bad contact of one CPU. Clean with alcohol and give it a careful polish with e.g. A fibreglass pencil.
 
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