MP 1,1-5,1 MacPro 3,1 (2008) won't turn on after Thermal Paste replacement

[midniter]

Hello,

I was experimenting with my old MacPro 2008. The taskmgr would show the CPU rev up on simple things like opening a new tab in Chrome for example. So upon doing some research I came to the conclusion that if I can replace the thermal paste I can get a better performance out of it.

I decided to replace the thermal paste on it and placed the CPU back. Reseated the RAM.
Now the MacPro won't boot up. It would do these power cycles over and over but no POST.

Upon reading some forums I have come to the understanding that the PRAM has to be reset ? I am not sure about this.

Any suggestions will be great.
Thanks.

 

[garrettstech]

How to Reset PRAM or NVRAM

1. Power off your Mac.
2. Press your Mac's power button and then hold these four keys at the same time: ⌘ + option + P + R.
3. Continue holding the keys until your Mac restarts for the second time. On older Macs, the chime will sound upon restart.

Even try switching the ram around that sometimes helps.

 

[Macschrauber]

After repasting you should not need to zap the nvram.

if you dont messed up something the clock battery is worth a meassure. Below 3 Volts it should be replaced.

Or the power supply is weak. Bet you plugged off from mains (you really should) and now the psu acts badly after replug. Common behavior of aged smps.

 

[midniter]

Thanks guys

Resetting the PRAM did not work.

The MacPro does exactly two power cycles, as indicated by the revving of the fans and then its quiet.

Next I will try to replace the clock battery.
I suspect its the PSU also. Replace it entirely ?

 

[Macschrauber]

Have you double checked all the steps? Especially if you plugged in the thermo sensors living in the heatsinks correctly?

 

[midniter]

I will recheck all the sensors and cables to make sure they are seated properly.

I remember that I had booted this MacPro from a Windows 7 x64 cd drive, with NO Bootcamp at all. For some reason it had worked. It was an experiment.

Is it possible that the MacPro has no concept of a boot loader as that information got wiped when I tried to make it into a Windows computer for gaming purposes ?

 

[Macschrauber]

If that was an uefi Windows you may have certificates in you nvram part of the firmware.

Hope you made a firmware backup.

You can try a deep nvram reset. You need an Apple USB Keyboard or another USB 1 Keyboard.

Hold alt-cmd-p-r while cold starting, keep holding all those 4 keys until the box chimes 3 times. Could take some time, hold it for 3 minutes or alike.

If the box comes back check the bootrom. Either with binwalk, hexedit (search for microsoft) or use the dumper I made.

 

[midniter]

It was win 7 x64. Not sure how to go about retrieving the certificates from NVRAM.

I believe I had not saved the Firmware backup. Is there a way to get that from the internet ?

Few things I tried:-

1. I changed the clock battery., produced no result.

2. I did try to reset the PRAM as advised above, but it looks like it failed. I tried it with a Windows Keyboard holding
Win + Alt + P + R

3. I also tried to boot from Win USB boot drive, didn't work.
I tried to eject the cd rom tray so I can insert a Win 7 x64 cd, but can't open tray.

4. The next step I was thinking about was to get bootcamp USB from my macbook and try to boot with that ? Does that even make sense ?

 

[Macschrauber]

if you use win usb installers you will get certificates, this can botch your nvram in the long run.

You can't get your firmware backup from the internet as it contains several machine IDs from your machine. Every firmware dump is different.

Check out the firmware thread from tsialex. It is for the 5.1 but many things are same. My dumper covers the 3.1 also.

A Windows keyboard may is not working for a nvram reset. Try to lend an old Apple keyboard for nvram reset.

 

[Madhatter32]

I have repasted my MBP twice. I think the older the machine the more benefit you will get. Just opening it up and cleaning out the accumulated dust in the fans wth compressed air (after taking precautions) should help performance. I repasted the first time after 6 years -- and the benefits were noticeable. I again repasted after 8 years and detected no real benefit. My conclusion is that a quality paste should give you 3 to 5 years at minimum before needing any attention.