Mac Pro 5.1 Won't Start! Please help :((

sok777

macrumors newbie
Original poster
Nov 29, 2018
5
2
I replaced my mac's gtx 680 with rx 580, and installation went well.
Before installing I cleaned all the fans with compressed air and when this ran out, I used a toothbrush to move dust and eventually carefully vacuumed it or took it out by paper.
It might have been slightly moist, but I don't believe this is the issue.
Now, when I plugged my mac pro I saw two red lights quickly blinking (ovtmp cpua and ovtmp cpub) I believe this is normal behaviour..
But Mac won't start! I press the power button and NOTHING happens. not a sound. I did take the cpu tray out so my only way forward is maybe the cpu moved or something? Is that possible?
Otherwise, I have tried the following: re-installing gtx 680 again. didn't work. reinstalling battery (3v) on board - didn't work. checked everything is connected properly, like SSD etc. Didn't work. Even tried pressing power on without the GPU or CPU tray - it didn't work.
I am really lost. Please help!
 

Alex Sanders74

macrumors 6502
Nov 26, 2013
272
59
Toronto, Canada
Sounds like the thermal sensors on the CPUs are not pleased. Maybe they got bumped in the cleaning process? I know you've checked over everything. Maybe try reseating the cpu tray again?
 

sok777

macrumors newbie
Original poster
Nov 29, 2018
5
2
Sounds like the thermal sensors on the CPUs are not pleased. Maybe they got bumped in the cleaning process? I know you've checked over everything. Maybe try reseating the cpu tray again?
Thanks so much for the reply. I have tried reseating the CPU tray several times to no avail .I don't have the tool to open the actual box in which the CPU did seats. Is it possible CPU moved? I did blow into it when I ran out of compressed air but can't imagine that'd do damage..?
 

Alex Sanders74

macrumors 6502
Nov 26, 2013
272
59
Toronto, Canada
There is some dialog on this post that might help you.

https://forums.macrumors.com/threads/2006-mac-pro-cpu-a-and-cpu-overtemp-led-on-plug-in.2119061/

What model of Mac Pro do you have?

Using a toothbrush is never a good idea on sensitive electronics, so I'm hoping that hasn't caused a hardware failure....

Try swapping the RAM trays and maybe put the gtx680 back in and see if that helps.
[doublepost=1543517949][/doublepost]Here's another post regarding a similar problem. I hope your logic board hasn't gone south....

https://forums.macrumors.com/threads/mid-2010-mac-pro-5-1-major-power-issue.2003237/#post-23642566
 

sok777

macrumors newbie
Original poster
Nov 29, 2018
5
2
OK for anyone interested, I solved it!
I had to replace the 3V PRAM battery! works like a treat. Not sure why it stopped working, but I guess the AC power disconnection did something to it.
By the way, the toothbrush was used only for cleaning the fan. The rest was with compressed air!
 

sok777

macrumors newbie
Original poster
Nov 29, 2018
5
2
Great news. Glad you got it working... also glad the toothbrush wasn't used for everything! lol
Lol yeah. I was careful and when the compressed air got finish I was too excited to clean it all :)
Thanks for your help!
 

howiest

macrumors 6502
Aug 16, 2015
295
115
Left Coast
When I saw this post I thought, oh no, not another one. Because let's face it, these machines are getting pretty old, and many of us are hanging on with fingers crossed.
So, glad to see all is well in this case. :)
 

sok777

macrumors newbie
Original poster
Nov 29, 2018
5
2
When I saw this post I thought, oh no, not another one. Because let's face it, these machines are getting pretty old, and many of us are hanging on with fingers crossed.
So, glad to see all is well in this case. :)
Thanks so much. I love this machine.
When I plugged it again to the usual plug, after it worked, it didn't power up! I was really shocked but when I removed and re inserted the power cable it worked again... might be that the power cable isn't great anymore too.
 

Alex Sanders74

macrumors 6502
Nov 26, 2013
272
59
Toronto, Canada
Lol yeah. I was careful and when the compressed air got finish I was too excited to clean it all :)
Thanks for your help!
Happy to help. Glad it was just a battery. My first thought was something got disconnected or damaged during cleaning. That's always a pain to diagnose and/or fix. I know I'd have a heart attack in that situation.