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PC Wont Boot - No Fan, No POST 5

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Jeff1994

MIS
May 18, 2004
33
US
Here's a problem that has me stumped. I've asked everyone I know, with no help. Whenever I shut down my computer, it shuts down and powers off fine. When I go to start it again, it does nothing. No fan turning, no POST beep, nothing. It's like it's not even plugged in. (IT IS!) Sometimes if I unplug for a while and then try again, it works, sometimes not. It's not a temperature issue, I've been monitoring that when the computer is running. I am getting power to the MB - even when it won't boot, I do get the green power LED on the MB. I thought maybe a bad power switch or bad connection to the MB. Any way to test a switch besides putting it in another computer? Here's what I'm running:

Antec Sonata case w/380 watt P/S
Asus A7V333 M/B
AMD Athlon XP 3000+ CPU
512 MB RAM (Kingston)
80GB Western Digital Caviar HD
ATI Radeon 7000 AGP
Plextor 708A DVD/CD
On-board (M/B) audio
 
you can test the switch with a VOM. You can test the motherboard by shorting the pins that the switch connects to.
 
This will be new territory for me. How (and with what) do I short the pins? I don't have a VOM, but I think I can get one.

Jeff
 
Jeff1994
This type of fault is typically either a bad switching power supply or something plugged into the motherboard ie: like an addon card, firewire/USB/modem etc remove all the addon cards and replace one at a time.
Martin

Start by questioning and soon you will be anwering.
So please take but remember to return and give when you can.
 
you can use any metal conductor such as a paperclip to short the pins you could even use a jumper, and it sounds liek either the switch or the powersuply. if its an ATX ps than just touch the 2 or 3 pins together for a sec, the reason being is becase the powerbutton is a momentery switch and you might shutdown your computer if you leave them shorted.. think of it as a "jumper switch". hope that helps!
 
OK, here's an update...

I tried shorting the pins to boot with no luck. The M/B has several headers for 1394 and USB ports, which I have unplugged with still no luck. The only cards I have are a Linksys network card in a PCI slot and a Radeon 6000 in an AGP slot. I was about to take out the Linksys as well as my optical and floppy drive, but there's a thunderstorm rolling in, so I will pick this up later this afternoon. Thanks for all your help.
 
Take everything but the video out and try that. Also try a different PSU if you can.
 
Still nothing with everything out but the graphics card. Here's something I'm wondering...

While I had my computer open, I happened to notice the P/S label that said "AC Input 115V/10A". I went and looked at my electrical panel, and they are all 10 Amp circuits. Is it possible that in my poorly built townhouse I'm just not getting a consistent 10 amps and that's keeping the P/S from having enough power to boot? It seems that if I keep pressing the start switch, eventually it starts - perhaps when I happen to press it at a time when I'm gettting a full 10 amps?

Just curious - I'm by no means an electrician!


Jeff C.

If all else fails, read the directions.
If that fails, REBOOT!
 
Remove and refit the graphics card
Remove and refit the main power plug to motherboard
Change the power cord if you can (swop it for the monitor lead)
Check you havn't fitted too many brass standoff mounting posts on the motherboard

I still think the Number 1 suspect is the power supply

Martin

Start by questioning and soon you will be anwering.
So please take but remember to return and give when you can.
 
Where do you live? I thought 15 amps was the minimum. That's a new one on me, though I doubt if you are pulling a full 10 amps. Try the PC in another room or make sure it is by itself on a single circuit. If you have a lot of things plugged in on the same circuit it could cause a problem. I'd suspect a bad power supply as has been suggested.

Jim

 
ANFPS26,

I'm in Richmond, VA, and every circuit in my panel is 10 amp. Luckily I'm moving over Memorial Day weekend, to a much more well-built house. I think the wiring in this townhouse is suspect, b/c we go through light bulbs like mad. Nonetheless, I'm suspecting the PSU as well. I'm going to pick one up and try it, hopefully I can return it if it's not the solution.


Jeff C.

If all else fails, read the directions.
If that fails, REBOOT!
 
OK scratch the idea about the wiring in my house - I'm an idiot. I finally broke down and took the computer to a local shop. They seem to think that it's NOT the PSU or the ATX power switch. He seems to think it's the CPU but is going to do more testing. Luckily I bought a retail processor that has a 3-year warranty. Has any one dealt with AMD on warranty issues?

Jeff C.

If all else fails, read the directions.
If that fails, REBOOT!
 
Why would it be the processor instead of the motherboard? The reason I am particularly interested is that I am about to send in my motherboard, which is failing to boot and only shows any power (fans spin, but no video or booting up process apparent) when I unplug the 4-pin power connector and the 12-pin and plug only the 12-pin back in. I would assume that the 4-pin is necessary, and I'm using a MSI K8T-Neo mobo with an AMD 64 bit 3200 processor. I tried a different power supply and got exactly the same behavior. I've got an RMA number from MSI and am about to send the motherboard in, but now I'm worried that it could be the processor.
 
I was skeptical when they said it was the CPU as well, but now they say it was the PSU after all. I think they kind of had a bad mindset against AMD - said they had only had bad luck. Anyway, I think the M/B or PSU is a more likely cause. My M/B is an older A7V333 and has only the 12-pin 12V not the extra 4-pin. Have you tried another PSU with your M/B?


Jeff C.

If all else fails, read the directions.
If that fails, REBOOT!
 
I've been using an antec 500 watt, tried a (working) antec 350 watt and got the same result
 
Sounds like the m/b to me - especially since it "sort of" works when you unplug the 4-pin plug, which is necessary for normal operation.

Jeff C.
A+, Net+, MCP, MCSA

If all else fails, read the directions.
 
Just an update to close this thread out. I got a new TruePower 380 from Antec (under warranty) and the problem disappeared. Thanks to everyone for the tips and suggestions!

Jeff C.
A+, Net+, MCP, MCSA

If all else fails, read the directions.
 
Good to here it's fixed, as I suspected the PSU was to blame, as usual other people get the stars lol.
Martin

Start by questioning and soon you will be anwering.
So please take but remember to return and give when you can.
 
I am having the same problems with a SOYO P4 MOBO. I get power and lights and fan spin but nothing else.
I replaced the MOBO the video card and the Memory and still I get nothing. Not even beeping. I also placed it on a bench and tried to power it up and I get lights on the MOBO and Fan spin but no splash/bio page. I thought maybe a shorted MOBO. I also tried a whole new case and power Supply nothing same thing.Could it be the CPU is bad? If I remove the CPU Should I still be able to boot to the BIO/splash screen??
Thanks,

Http:\\"It's the 21st Century I was promised a flying car! Where is my flying car?"
[afro]
 
JerryUSA
Have you cleared the cmos? removed the battery for 10 minutes?
As you have already swopped out all the obvious a new CPU seems the last resort and one which certainly could give you these fault symptoms.
Martin

Start by questioning and soon you will be answering.
So please take but remember to return and give when you can.
 
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