just a quick question before I go buy stuff[resolved]

Post by **matsif** » Fri Apr 13, 2007 2:54 pm

ok my current prob is that my computer will not start. when I hit the power button, all the fans spin up, but the BIOS wont boot. am I right in getting a new mobo, or should I check other things first, such as vid card, RAM, CPU, HDD? I really need to get my comp back up and running as this junker I am on now is too old to have a SATA connector for my hard drive, and I need stuff on there for school (and to get back for GC play, but thats beside the point)

thanks a bunch,
matsif

Hashey · Post by **Hashey** » Fri Apr 13, 2007 4:07 pm

Sounded like a problem i had with my old Dell pc. Took it to the PC shop and the guy checked PSU and said it worked and that they had to have it for a day or so to check out what was wrong. Turned out that the PSU was broken so they replaced it. Could be the same problem though, but just to be sure i'd suggest you take it to a pc shop to have them take a look at it.

Post by **matsif** » Fri Apr 13, 2007 4:13 pm

but if the problem was the power supply, how come my fans on my CPU heatsink and the fan on my vid card spin up? they are directly connected to the mobo and they still work fine

Hashey · Post by **Hashey** » Fri Apr 13, 2007 5:01 pm

That's what i couldn't understand either. My fans worked normally but my computer just wouldn't start up. But as i said, take it to a pc shop where you can have it looked at and find out what the problem is.

styphon · Post by **styphon** » Fri Apr 13, 2007 5:30 pm

Could be a number of things. First off I would disconnect the power cable and then take out the BIOS battery. This will reset your BIOS incase there is a problem there.

Next, disconnect absolutely everything except the RAM. Turn it on and see if it will POST (it'll beep if it POST's). If it doesn't post then take the RAM out and try again. If it still doesn't POST then either the PSU, Mother Board or CPU are fraked.

If it POST's with the RAM in first time then start adding things back in, Hard Drives, CD/DVD/Floppy drives, Graphics Card, Fans, in that order. If it fails at any stage before fans then thats probably your problem. Just to be sure, unplug what fails and plug the next thing in on the list. If it passes second time then you know whats fraked. If it fails on both then it's probably a power issue.

Post by **matsif** » Fri Apr 13, 2007 6:53 pm

well, here's what happened:

I plugged the PSU of my pc into the junker, and lo and behold, I heard *twink* and smelled buring plastic, so now my PSU is definately done. hopefully that was the problem, cause a PSU is much less expensive than a motherboard, and I can buy one locally, being my parents hate the internets/computers for some reason.

going to worst buy tonight to pick one up, and possibly guitar hero 2 for the xbox360! woohoo!! maybe I will make the battle tomorrow

do not change this topic to resolved yet though, because I may still have problems. will report with new PSU later

Post by **Ash2Dust** » Fri Apr 13, 2007 8:16 pm

Power supplies have different power rails. The 5v rail must have been decent as it powered the fans. The other voltages may have not been within the 10% specs so the motherboard wouldnt boot. Hopefully nothing was damaged in your computer if any of the voltages were too high (most likely not).

Quality power supplies are heavy and can smash a windshield. Crappy quality power supplies will get their butts kicked by the windshield.

You may or may not want to get a PSU with SATA power connectors. Most SATA drives currently still accept the old school Molex connectors. Plus you can buy power adapter cables if needed.

Titi · Post by **Titi** » Fri Apr 13, 2007 8:40 pm

Re: Ash's response.
When I researched my new system 15 months ago, the Power supply was the most mysterious to quantify. Ash put it in qiuck non-scientific terms.
Brick wins, plastic loses.

Post by **matsif** » Fri Apr 13, 2007 9:28 pm

got new PSU, took out everything cept CPU, still didn't POST. ordering new mobo as it has to be the problem at this point. I did what styphon suggested, and got down to the CPU and vid card as the only things in just to try something, and it still didnt POST. when I had everything in and connected to the new supply, it still didn't work. everything turns on except my disc drives (prolly cause IDE is fried or something) and my wireless internet card/sound card, which is telling me that the PCI slots aren't recieving power, either. my HDD spins up, as I can hear that.

prolly ordering new mobo tomorrow. gl hf

Winter_Lion · Post by **Winter_Lion** » Sat Apr 14, 2007 7:23 am

Power supplies have a voltage sensing wire that checks available voltage on the motherboard at boot up. The fans will run, because they run off a different power bus then the highly conditioned power that feeds the Motherboard.

Anyways, if that sensing wire doesn't sense the proper voltage on the motherboard it won't allow the PC to boot......this is to protect the motherboard for the most part.

The best way to troubleshoot this kind of problem is to substitute a known good psu and or motherboard or as it was posted above......take it in to your local computer repair shop for diagnosis.

Winter

Post by **Ash2Dust** » Sat Apr 14, 2007 1:14 pm

Also make sure you got the 4 prong 12v power cable plugged into the motherboard from the power supply.

Just to clarify, you need PSU, MB, CPU, and 1 stick of RAM to hear signs of Bios boot. Remove/disconnect all else.

The BIOS will beep at you if it starts up and doesnt find a video. But thats a good start and you can then add the video in.

Motherboards are a pain in that I usually do a clean install of Windows rather than have the old motherboard drivers still floating around. Unless its the exact same model and version number.

Good luck, sucks having to guess at the problem. Not like we all have a logic probe and a schematic of mb laying around so it really is a process of elimination. There are PCI cards that can be plugged in to see what stage the BIOS boot is at, but those seemed to get outdated every other year.

Post by **matsif** » Wed Apr 18, 2007 8:56 pm

thanks for the help guys but the problem did end up being my mobo. now I got a new one and everything works fine.

resolved

styphon · Post by **styphon** » Thu Apr 19, 2007 8:01 am

Ash2Dust wrote:Just to clarify, you need PSU, MB, CPU, and 1 stick of RAM to hear signs of Bios boot. Remove/disconnect all else.

You can actualy do it with nothing in but the board and power. It'll fail the POST when it scans and detects nothing, but it will at least attempt it. If it doesn't even atempt POST with nothing in then the board is screwed.

Post by **Ash2Dust** » Thu Apr 19, 2007 12:38 pm

I'll have to try it sometime, its been several years. With onboard speaker and voice, that makes sense.