Computer shuts off with no warning

[nitecrawler0919]

so just got a new setup... new MOBO, CPU, RAM and i set it all up and got it running and then i ran into an issue with the computer shutting completely off while in the process of installing a clean copy of windows 7. well i got through that by setting the CPU into power saver mode and booted into the windows 7 disc under safe mode, so now the O/S is installed and evrything is running and then...BAM! turns off. does not restart, when pressing the power button it does nothing until i flip the switch on the PSU to off then on and then it boots up and shuts off again at random different times.

so im not a complete GURU with computers but i have been building new PC's for about 8 years now and ive learned alot but there are alot of things that i still need help with.

but please i know for a fact that this is not an overheating issue because as soon as it shuts off i turn it back on and go into the BIOS and check the temps and granted the time between boots will have given it time to cool down but if it was at the point where it would shut off due to overheating it should not have cooled down all the way to 28C in a matter of seconds. so please no suggestions on the overheating aspects of it.

but what i am asking is for a few opinions from other techs on whether my suspicions, of the PSU being the main issue, are correct.

this is my setup:
ASUS Sabertooth 990FX,
AMD FX8120,
16GB Corsair DDR3 PC1600,
3 SATA II HDD's(160gb,250gb,500gb),
ATI Radeon HD 5750,
CoolerMaster N212 CPU cooler,
Rocketfish 700W PSU,
Super writemaster DVD/RW SATA drive,
UEFI BIOS v 1208,
ANTEC 900 case.

any help would be greatly appreciated

[ShyguyXPC]

Its a Rocketfish... Best Buy's brand... what do you think?


I know some Rocketfish PSU's in past have been built by FSP or Seasonic, or at least I remember reading that, but some aren't as well. Its like Rosewill, newegg's brand, and Ultra, Tigerdirects brand.

not sure if its the same company, but in years past, Huntkey was the builder of their Rocketfish and Dynex PSU's, and Huntkey is not known for top quality products, some of their PSU's have been ok, but most i hear of are rubbish.

No idea who makes this particular unit you have, as this was back in 2008. But if you could post the actual model number or part number for the PSU, that might make searching a little easier.

Otherwise, if you can afford a new PSU, to test out, I'd consider getting one from a reputable brand like Corsair, Antec, Seasonic,etc,

based on your hardware specs listed above, you certainly don't need a 700W PSU, unless you plan on running Dual 5750's or something, even then, you wouldn't need 700W.

your lucky if your pulling 400W on your current system.



just the fact you listed you put the CPU in power saving mode to boot windows install disc, tells me its a power or heat issue.

Did you connect the 4+4 pin or 8 pin EPS/ATX 12V Supplementary power connector to the board as well? (Besides the 20+4 pin ATX)

as to the heat issues, I know you said no suggestions, but is the heatsink on secure and evenly?

[nitecrawler0919]

Its a Rocketfish... Best Buy's brand... what do you think?


I know some Rocketfish PSU's in past have been built by FSP or Seasonic, or at least I remember reading that, but some aren't as well. Its like Rosewill, newegg's brand, and Ultra, Tigerdirects brand.

not sure if its the same company, but in years past, Huntkey was the builder of their Rocketfish and Dynex PSU's, and Huntkey is not known for top quality products, some of their PSU's have been ok, but most i hear of are rubbish.

No idea who makes this particular unit you have, as this was back in 2008. But if you could post the actual model number or part number for the PSU, that might make searching a little easier.

Otherwise, if you can afford a new PSU, to test out, I'd consider getting one from a reputable brand like Corsair, Antec, Seasonic,etc,

based on your hardware specs listed above, you certainly don't need a 700W PSU, unless you plan on running Dual 5750's or something, even then, you wouldn't need 700W.

your lucky if your pulling 400W on your current system.



just the fact you listed you put the CPU in power saving mode to boot windows install disc, tells me its a power or heat issue.

Did you connect the 4+4 pin or 8 pin EPS/ATX 12V Supplementary power connector to the board as well? (Besides the 20+4 pin ATX)

as to the heat issues, I know you said no suggestions, but is the heatsink on secure and evenly?

thanks for your input

so as for the question about the heatsink, yes its secure and even, the back plate for it holds four nuts that screw in directly onto the heatsink frame and they are tightened to 120 in lbs ( yes i used a torque wrench lol ) and the four holes in the actual motherboard ensure proper alignment.

yes i made sure that i plugged in the 4+4 connector onto the MOBO which is meant for the CPU and it is seated properly lol i was really careful to triple check everything i plugged in when i built the system lol

so im not too familiar with voltages and power pulling, but when i purchased the 700W PSU i figured that it would be suitable for anything that i put in the system and it was until i upgraded my system and now this issue happenned and now i need to plug this PSU into another system i have and testing it.

i will be looking for the S/N as soon as i am back at my rig and start searching for the specs for it but yes i can say that i did purchase it at BEST BUY because i had an employee discount on it so yah its best buy made i believe.

so thanks for your input again and i will be running more tests to see if i can get this rig to work for more than 3 min lol

so what PSU do you recomend for this setup? i used the newegg PSU calculator and it said that i need 455W to run this setup so i was thinking a 500 or 550 just in case i try to update my vid card anytime soon

[ShyguyXPC]

Neweggs PSU Calculator is a joke, its really really basic.

Use this one instead.

Much more accurate.

eXtreme Power Supply Calculator

When I made the statement above about your lucky if your pulling 400W, that was the calculator I used, it was actually under 400W, but I just rounded it up for discussions sake.




Do you plan on stuffing a 2nd Radeon 5750 in that rig, or upgrade to a single better GPU?



It may not be the PSU, but out of the list of parts, and what you described, that would be my first suspect.



as to a good unit that would power your current system as is...

Newegg.com - SeaSonic M12II 520 Bronze 520W ATX12V v2.3 / EPS 12V v2.91 SLI Ready 80 PLUS BRONZE Certified Modular Active PFC Power Supply

Newegg.com - Antec NEO ECO 520C 520W Continuous Power ATX12V v2.3 / EPS12V 80 PLUS Certified Active PFC Power Supply

Newegg.com - COOLER MASTER GX 450W RS450-ACAAD3-US 450W ATX12V v2.31 80 PLUS BRONZE Certified Active PFC Power Supply

Newegg.com - CORSAIR Builder Series CX500 V2 500W ATX12V v2.3 80 PLUS Certified Active PFC Power Supply

The Antec and Seasonic are the same internals, just the Seasonic is Modular. The Corsair is good too, also internals made by Seasonic.

the Coolermaster is a good one as well, but the other 3 have a higher rated +12V Rail.

all of these have enough power, with some to spare.



if you were to run Dual Video cards, this Unit would be more than enough for a couple 5700/6700 cards with your current system, and would actually be able to run a couple 6850's together as well.

Newegg.com - Antec NEO ECO 620C 620W Continuous Power ATX12V v2.3 / EPS12V 80 PLUS Certified Active PFC Power Supply

Or Dual 7770's (which are almost as powerful as the 6850, with exception in some areas, like Antialiasing and shadow effects at higher resolutions, but the 7770's only pull about 80-90W of power, versus the 6850's which use closer to 120-130W from what I remember).

Actually looks like Dual 5750's with your setup would pull around 400W or a bit over that, so even the 520W Antec/Seasonic would be enough for that.

But in case you planned to upgrade to a much more powerful card, for example a 200W range card, then I'd certainly consider the 620W Antec or something similar.


Newegg.com - CORSAIR Builder Series CX600 V2 600W ATX12V v2.3 80 PLUS Certified Active PFC Power Supply

[nitecrawler0919]

thanks for all your help i really appreciate it, the issue was the PSU apparently it was faulty and i just purchased a new better one ( the SeaSonic 520W you suggested) so again i appreciate all the help and i guess i should have tested the PSU straight from the begining but there were alot of coincidences, that made the PSU being bad the culprit, not seem likely but i guess it was so thanks again.