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Very peculiar problem...need some input please

  • Homebuilt
  • Systems
Last response: in Systems
October 29, 2011 10:22:29 PM

I just recently bought all new components for a new pc and before diving into the issue here are the specs:
Biostar|TZ68A+ Z68 LGA1155 Mobo
Intel core i5 2500k
Asus gtx560 DCII
8G corsair ram 1600
1TB 7200rpm WD HDD
Rosewill Hive series 650W

Once I got everything put together and hooked up, I tried booting the system but there was no power getting to the system. I tried many different things including:
1. running mobo in cardboard box to check for a short-still no power

2. Using a different PSU-yet again no power. I then determined the mobo was DOA

3. New PSU in old system to make sure it wasnt a bad PSU-it turned on but was still unable to boot

4. Got yet another computer from the office(which works fine) and used my new PSU with it-it booted up like normal which makes me think that either my old computer(which was working fine before i tried the new PSU in it) randomly stopped working or whatever happened to my new computer happened to it as well

5. New GPU in pc from office-everything powers on, but motherboard fails to boot BIOS and turns itself off

6. Old GPU from old pc(9800GT) in pc from office-same exact thing as new GPU

The only thing I can think of is the GPU isnt getting enough power, but how can a 650W PSU not be enough? especially for a 9800GT...I also thought maybe the PCIe6+2pin to PCIe6pin was somehow losing power between the conversion(asus requires 2xPCIe6pin power, PSU supplies 2xPCIe6+2pin cables)
I'm really at a loss with this...any help or suggestions would be appreciated. Thanks

More about : peculiar problem input

a b B Homebuilt system
October 29, 2011 10:58:22 PM

1. New motherboard is DOA ==RMA
2. Old computer now no good==trash
3. New gpu defective and old gpu gone bad ==RMA new gpu , trash old gpu
4. New psu maybe defective as well ==RMA just to make sure.
Whatever you end up doing you better do it before the 30 days is expired , and this is what I got from all your testing (as best as I can figure)
a b B Homebuilt system
October 29, 2011 11:18:09 PM

tough to diagnose. Did you try a different wall socket ? the heat sink is mounted properly ? never used rosewood power supplies. it says it has enough power for what you have. but I use more name brand stuff. you have the 20/24 pin and the 4/8 pin up by the processor plugged in ? all connections tight ?
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a b B Homebuilt system
October 29, 2011 11:30:14 PM

It would be very rare for a new mobo or PSU to be DOA as these are checked before shipment. You might want to slowly work thru the "no book checklist" below to see if you can find the real issue. It's often something simple.
a c 78 B Homebuilt system
October 30, 2011 12:10:47 AM

I don't know the problem any more than anyone else here, but I just wanted to say that you should not look at the number of watts on the PSU and try to draw any conclusions from that.

The only thing you can draw conclusions from are actual tests by reputable websites that employ special hardware. See the link below.

In the top stats box the bottom row should all say "pass" and in those charts at the bottom ideally the top to bottom lines should be much less wide than these are. This device looks like it is barely passing on the 12vs which is where you really need the best performance.

- Edit - I wanted to point out, if you look at the text in that review, the reviewer had the nearly the exact same problem you are having. When there is heavy load on the device (like that spike that occurs right when you start the PC when each item tries to draw its maximum amount at the same time very quickly during POST) then the device wouldn't turn on. They only got it to turn on by starting the load low and then moving it up high later.

They can do that with special equipment. With computers, its much harder to tell them NOT to draw max power as part of POST.

The website gave the PSU an overall OK rating, but I wouldn't rule out the PSU as the source of *your* problem. I would hazard a guess that as long as you are using the spacers between the motherboard and the case that 66% - 75% of the time if a PC won't power on it is a PSU problem.

Even if the devices are new, it doesn't make any difference. The difference between a name brand PSU and a no name PSU is night and day. Antec Earthwatts 430w can put out more power than most no name 800w power supplies.

- Edit 2 - Try taking everything possible out of the case. Make it so that the only devices connected to anything are the power connectors (a 20 or 24 plus a 4 or 8) that go to the motherboard and the power button to the motherboard and try to turn it on. If the PSU and the motherboard are even remotely functional, the CPU fan should turn on and spin continuously.