2009 Mac Pro Suddenly Won't Power Up Anymore

[Frank DiMaulo]

Great thread!!! Very helpful as I have a very similar problem. At the moment my MP 4,1 turns on, fans spin... and nothing else. My question is if I replace the backplane board and i've already flashed my 4,1 to a 5,1, will I have a problem with my upgraded 6 core cpu's?

 

[NCMcClure]

Great thread!!! Very helpful as I have a very similar problem. At the moment my MP 4,1 turns on, fans spin... and nothing else. My question is if I replace the backplane board and i've already flashed my 4,1 to a 5,1, will I have a problem with my upgraded 6 core cpu's?

Yeah, sadly your 6 core CPUs won't work with a non-flashed 4,1 backplane. Luckily the backplane that I ordered from dncomputers.ws came pre-flashed to a 5,1. If you can a find a backplane that's been flashed already then I would just go that route and it will be pretty hassle free.

If for whatever reason you can't seem to find a pre-flashed one or can't find any pre-flashed ones within a decent price range ($120-$200) you could always buy a couple X5550 CPUs for super cheap on eBay, use those to get everything running, and then flash the new 4,1 board to 5,1.

 

[Frank DiMaulo]

Well... I got a pre-flashed backplane board (5.1), installed it and nothing has changed. LED lights up on the front, fans spin up, hard drive spins up, fan on my original GT120 video card spins up but no boot up. The drive does not seem to be making the usual boot up sounds, it just spins. I tried different system drives... nothing. Could it be the power supply with all that activity? The LED status lights on the backplane board show that the PSU is "OK". Any insights are welcome.

Update: Ordered PSU, fingers crossed.