Sign in with
Sign up | Sign in
Your question

CPU Won't power

Tags:
  • CPUs
  • Power
Last response: in CPUs
Share
March 28, 2011 6:32:11 PM

Hi!
My current rig is

Athlon X2 4400 (untouched, no OC)
HD3850 256MB
2GB RAM
Got 2 WD HDD's, 160GB + 500GB.
GIGABYTE M55S-S3 Rev 2.0, BIOS updated to latest version (supports the 555).
A crappy Thermaltake 400W PP (350AR-PTZ model) - It's a horrible one, i know. 25A total on 2 +12V rails if i'm reading this right, it's basically a generic 350W PSU it seems.

I bought a new CPU and video card today, a Sapphire HD5770 and a Phenom II X2 555 BE.
Replaced my old crap, but hey-ho, now it doesn't run. The PC itself is on, but the CPU isn't - The monitor didn't power as a result of course.
Video card works fine.

I immediately thought of the PSU because i suspected this might happen.
Did some tweaking, installed my old HD3850 back and kept the new CPU on, same problem, it didn't power.
Put my old CPU back on, violix, everything works fine, though i have yet to test it in stress, just idle.

I want to make absolutely sure what's the problem before i go out and buy a new PSU because i'm short on cash right now.
I'm pretty sure i installed the new CPU just fine, everything seemed to fit nicely.
Then, maybe it's the BIOS not having been updated properly? I actually flashed it using GIGABYTE's @BIOS program from Windows easily, the software says i have the newest version now, is there anyway to confirm it in the actual BIOS when booting into it?

If you're sure PSU is the problem, i'd appreciate some help on that front, would a Corsair CX500W be enough to power my new rig (will definitely add 2GB in the near future as well)?Or will i absolutely have to get the CX600W? I've got both available in my nearby store and have read good reviews.
Also got a SeaSonic M12II 520W available, if that's any better.
Thanks.

More about : cpu power

a c 81 à CPUs
March 28, 2011 7:46:32 PM

Check which version of the BIOS you are running.. Version FJI is needed for the Phenom II 555..
m
0
l
March 28, 2011 9:17:01 PM

Like i said both @BIOS (GB's flashing software) and CPU-Z identify BIOS having the latest version, that would be FJI yes.
I've no idea how to confirm it otherwise, i haven't found anything in my BIOS that points to the current version.

I need help on this guys, i don't want to do something incredibly stupid like buying a new PSU (i know i need one anyway but that's not the point) just to find out that my mobo is actually at fault.

Just to clarify, everything else in my PC seems to work when i turn the power on. The video card's cooler is working, my DVD-ROM works fine etc. It's just the CPU apparently not turning on.
Does that point towards a faulty PSU, or mobo? Or maybe the CPU itself is screwed up even thought it's brand new?
m
0
l
Related resources
a c 157 à CPUs
March 28, 2011 10:07:32 PM

Gigabyte shows its supported on 2 different listings I checked. Try resetting the bios back to its default settings then save and power down and swap processors. Perhaps it is a custom setting that is not allowing the cpu to be autodetected.
m
0
l
a c 172 à CPUs
March 29, 2011 1:33:25 AM

The 5770 requires only a little more power (10 - 15 watts) than the 3850, so that is probably not your problem.

First rule of upgrades - make sure that the parts are compatible.

Second rule - if possible, upgrade one component at a time. Does the system work if you only upgrade the video card?

If not, check out the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

If the system works with the new video card, then replace the CPU and repeat the above steps.
m
0
l
March 29, 2011 10:11:49 AM

popatim said:
Gigabyte shows its supported on 2 different listings I checked. Try resetting the bios back to its default settings then save and power down and swap processors. Perhaps it is a custom setting that is not allowing the cpu to be autodetected.


If i do that, wouldn't that revert the BIOS back to the original version, which doesn't support Phenom II's?
I'm still trying to find a way to check my version in BIOS itself but no joy so far.

jsc - i don't have a DMM handy and even if i did that sounds a bit too over my head.
Unfortunately i don't have a good PSU handy either. My brother's PC has another 400W generic one if i recall correctly.

Any help is appreciated, i might be able to buy a new PSU today but need to make sure that's the problem.

The real question is, can it be a BIOS issue if the CPU won't even power up? I'm not talking about not booting into Windows or something, it just doesn't power, at least the cooler doesn't so i assume the CPU doesn't either. The PC feels like it powers on and off and like there's insufficient power.
From what i've read if the BIOS doesn't support the CPU you at least get some message on the screen?
And it can't really be a dead mobo either if the PC runs fine with my old CPU, right?
m
0
l
March 29, 2011 11:28:29 AM

Alright, quick update, did what popatim suggested, went into BIOS and loaded optimized default settings, put my new CPU in and the computer wouldn't turn on at all this time.

Yesterday the rest of the hardware seemed to power like i said, just not the CPU, now the entire machine won't power, just hitting the power button and getting no response.

Still works perfectly fine with my old CPU in place (i'm writing from the same PC).
What's going on? Is the CPU fried or dead? I just bought it yesterday, brand new.
m
0
l
!