MP 1,1-5,1 Mac Pro 5,1 fans ramping up after chime

[realLucaR]

Hello everyone! So I got a Mac Pro 5,1 (not 4,1) and it gives me nothing but problems so far.

At first, I used a 5,1 backplane with a 4,1 CPU tray, which obviously makes the fans spin at 100%. Now, I got a 5,1 CPU tray and it still does the same thing, just different now. Now, the fans don't immediately ramp up, no, they ramp up after the Apple 'gong", and they ramp up slower until they reach full blast.

Also, I cannot get into Mac OS X at all. At first, I still had Snow Leopard installed, when the 4,1 mainboard was in, now I have a 5,1 backplane and CPU tray.

I reinstalled Lion with the official Mac OS X Lion USB that was supplied with the MacBook Air. Installation went through fine no problem. As soon as I try to set up the time zone, boom, no signal.

I reboot the Mac, enter my account password, boom no signal. The signal immediately drops on lock screen, and it starts to REALLY piss me off.

So, I have a machine that shows me now input after entering the password and blasts the fans at full speed. It is so frustrating.

Specs:
Some Quad Core Xeon
32GB DDR3 ECC
1TB Samsung SSD
Nvidia GeForce GT120

Can anyone help? I tried PRAM, SMC and so on, all the resets. I also triple checked; it is a 5,1 mainboard and a 5,1 CPU tray.

Also, the mainboard I use is brand new as well. It is an old stock 5,1 mainboard and it has never been used before, brand new.

 

[tsialex]

Recommissioning a Mac Pro that was not working for some time is not a simple task. You probably have more than one issue at the same time.

I'd start measuring the BR2032 RTC battery voltage (this is the first thing I do, even before installing the backplane to the Mac Pro), verifying all fans + temperature sensors and then double check if the GPU really works with a working Mac Pro.

Inspect each one of the fans connectors, if one is not sending back the rotation signal, the SMC is going to enter failure mode and all fans go full RPM.

Inspect the northbridge push-pins and the heatsink temperature sensor, if the sensor is disconnected or damaged, the SMC will ramp up the fans. Btw, this was the failure that took several days for another user here to find.

Apply contact cleaner before reconnecting everything, oxidation happens even with sealed boards.

If you can make it stay working enough to boot, then you should run AHT or ASD EFI and post the error code here. This will most certainly give a clue about the real problem(s).