2006/2007 Mac Pro PSU temp sensor connections

[fastpat]

I'm having an issue with the PSU cooling fans running at their max rpm, 2800. Hardware Monitor shows that the PSU temp sensors are disconnected.

Last Monday I changed the CPUs from dual to quad core units, from 5160s to 5365s, so it's possible that I caused a connector to pop off, if they're under the main dual cooling fans. I can't seem to locate that info, though, and before I disassemble things again, I'd like to know if those connectors are in the area where the PSU connects with the mother board.

Does anyone know of a photo of diagram illustrating where the PSU temp sensors connect to the mobo?

This is a September 2007 Mac Pro build, with the ROM upgraded to 2,1 status, running Lion 10.7.2, and plenty of RAM. smcFanControl is installed, but won't control the speed of the PSU fan now.

 

[nambuccaheadsau]

There is a heat sink connector under the processors. Installing X5355's, left mine from the motherboard and was like a jumbo taking off.

 

[666sheep]

^^^Not in this case. PSU not CPU fan went crazy.

OP: check connection of PSU #4 cable (control PSU). IIRC it's on the bottom of LB, under lower memory riser connector.

 

[fastpat]

Thanks, Mr. 666sheep, I'll have a look this evening.

 

[fastpat]

Well, I just had one of those "it can not have been that easy" moments, but it was that easy.

Opened the Mac up, took out both memory risers, pushed all of the connectors together, did NOT notice any movement, put it all back, plugged it all in, and fired it up.

Problem solved. PSU temp sensors are now outputting the PSU temps and the fans are back to normal rpm.

Love the quiet.

Thanks, 666sheep, for your fast response and help.