Motherboard appears to recieve power, but not much else 5

[djeddiej]

Hello -

I am dreading the worse case scenario, but for now here is the issue.

I had set up a system running an ASUS P4S800 Motherboard, P4 3.2 gHz 1 Gig RAM. It is attached to an older 425 W Power Supply. It was running fine with 4 HDs, DVD, CD, all PCI slots filled and an ATI AGP 8x card.

I had the case open to monitor the devices and tidy up the connectors. A spark flew (something shorted, I suspect the power switch), and the connector to the onboard PC speaker was hit by the spark, but fortunately (?) the whole PC powered down. The only physical signs of damage are a semi-melted wire connecteor to the onboard PC speaker.

I have removed the onboard speaker, and examined all parts...everything physically appears intact.

When I rettach the power cable to the power supply and turn on the power supply. The StandBy Power LED on the mobo turns green when the power supply is activated, indicating that power appears to be coursing through the motherboard.

However, when I actually turn on the switch. click. nothing. NO post. NO Beeps. No fans. No whir/click of hard drives or DVDS.

So I am wondering what the problem could be, what to troubleshoot, and what to look for.

-bad/shorted power supply switch?
(should the power supply be grounded/attached to the tower?
-bad power supply? (not sure of this one, as I see from the mobo's green light being on that power is going through...)
-(worse case) bad mobo or CPU? How one would be ablt to tell if these were fried :<

I would appreciate any help...been building this system for three odd weekends and would be disappointed if the whole thing went kabloo-ey.





Edward J. Apostol
Web Application Development Programmer
Toronto, ON Canada

 

[garebo]

Look for burn marks around, even under the agp slot, or actually anywhere else on the mobo as well, on or near the north and south bridge chips which are large chips, sometimes with fans and\or heatsinks on them.


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[paparazi]

djeddiej
Yes clearly it's compatible, doh!
Have you used your backup PSU yet? worth a try despite your existing one appearing to be OK.
Martin


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Participate and help others.

 

[djeddiej]

I did not try the backup PSU because it is an ATA one.

I am pretty sure my vid card works (I tested it on two other machines) so it looks like the AGP slot may be foo'd. Upon inspection of the mobo, however, I have found no burn or scorch marks on the mobo or particularly near the AGP slot.

I also tried a (slightly older) ATI 64 Meg AGP card as well to the same effect - I turned on my computer, no beeps, no black screen.

I have ended up returning to the shop (under warranty)...the store clerk informed me that he will follow up in a few days. I suspect that they will do testing as well to confirm the problem is in the AGP slot. We'll see what happens.

A thought occured to me though, should I replace the PSU completely? I know it runs, and it powers the mobo, but...maybe not enough power for 4 drives, DVD, and 5 fans (4 80s and 1 for CPU?) - its a 425 Watt


Edward J. Apostol
Web Application Development Programmer
Toronto, ON Canada

 

[franklin97355]

425 watts is enough (if it is working correctly)

 

[paparazi]

djeddiej
425watts !!! as the actress said to the vicar "quality rather than quantity.
Basically depends on if this is a good unit, 425watts doesn't mean jot if a cheap generic unit.
Look for top brands like:
Antec, Enermax, FSP, CWT, Fortron power, Tagen, Thermaltake, Zalman, Chieftech
Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[garebo]

With all you have running you should have a decent power supply.
Names brands are important, but there is another way to judge the quality of the power supply. If it is real light then its a cheap unit. If its heavy or much heavier than the cheap, light unit, then its likely a better quality power supply. But the power supply that comes with a standard case is always a cheepie.
Suggest you get an antec, enermax, or one of the others paparazi mentioned. When you go to upgrade you can keep your power supply and whatever else you want to keep, sell the rest and get your upgrades. That way you have a good power supply to start with.
You can always take the old power supply apart and take the fan out of it, makes a good case fan.



Good advice + great people = tek-tips

 

[djeddiej]

Hi -

Just to follow up a week later.

My motherboard has been replaced, and after 6 hours of reassembling the inside of the tower (organizing and tying wires, tightening all bolts, placing the CPU/heatsink/fan etc. back on) the system is back online...and the power switch is firmly screwed into the tower and grounded.

I am running a backup now of the system...

All I can say is whew! Don't want to go through that again, but thanks to everyone for their help.


Edward J. Apostol
Web Application Development Programmer
Toronto, ON Canada

 

[garebo]

Can I make one more suggestion now that all is well?
Surely this machine is important so if it isnt perhaps you should consider connecting it to a UPS. I kind of rant about that but all computers should be connected to a UPS.
Power surges and brownouts only last part of a second and can do a ton of damage to a computer and a UPS can help prevent this.
It may or may not have helped in your case but they do work, and with the low cost today, its kinda crazy not to have a UPS on your system.


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[garebo]

Sorry, one more thing.
That power supply, what is the make of it and how old is it?
That would give you an idea of how valuable the claim of 425 watts of power is.
If it turns out to be an older, cheaper power supply then you should replace it and keep the old one as an emergency spare.
Cheap power supplies have only a few molex (white, flat, 4 pin connectors), perhaps 4, while a better power supply has 6,7 or 8 molex. also look for extra sheathing on the main power cable coming from the power supply to the molex connectors, 2 fans instead of one, fan covers that come off instead of built into the power supply, things like that. To me, weight is the biggie, you can always tell a good power supply by its weight. But the visuals help too!
Here is a list of good and bad power supplies that i got from a web site, no guarantees on all of them being listed correctly, but the well-known ones should be in the correct list. I cant remember just where i got this list but I believe it to be a good source.

Good:
Antec Astec AOpen Channel Well I heard Chieftec power supplies are rebadged ChannelWell PSUs
COOLERMASTER Enermax Enlight
Fortron Source (Sparkle) FSP GROUP
HEC HIPER Hi-Power Jeantech NSpire
PC Power & Cooling PowerMan Seasonic
SilenX Tagan Thermaltake TTGI/SuperFlower
Vantec Verax Zalman
CHANNEL WELL AND SKYHAWK ALSO GOOD

Bad:

Achieve Allied Aspire CoolMax
DEER ( some MAY BE OK)
EYE-T KingStar L&C Linkworld PowerMagic
PowerUp Powmax Q-Tec Raidmax Skyhawk
Star Turbolink

Not Enough Info:
AGPB Aerocool Ahanix Codegen Cooler Master
Dynapower USA Kinwin Silverstone Soyo ULTRA









Good advice + great people = tek-tips

 

[djeddiej]

Cheap power supplies have only a few molex (white, flat, 4 pin connectors), perhaps 4, while a better power supply has 6,7 or 8 molex. also look for extra sheathing on the main power cable coming from the power supply to the molex connectors, 2 fans instead of one, fan covers that come off instead of built into the power supply, things like that. To me, weight is the biggie, you can always tell a good power supply by its weight. But the visuals help too!"

It has 8 molex, 2 fan, fan covers do come off...
seems to fit your description, unfortunately I cannot see the brand name at this point (label on top, and is covered by 2 hard drives just above it), I bought the adapter I believe in 2000...I think its ok...

UPS...I have one, but software does not run in Win XP (believe it or not) its some old belkin UPS - software ran in Win 2K/98, but does not seem to work properly in XP...nonetheless (I think) its running, I enabled a generic UPS service inthe services control panel and it appears to be polling...(or something).




Edward J. Apostol
Web Application Development Programmer
Toronto, ON Canada