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

 

[paparazi]

Surely it didn't just do this on it's own?
Did you trap a wire or something?
The fact that the speaker wire burned must mean it was grounded in someway.
OK! first suspect has got to be the PSU but you have to find out what happened first, no point in connecting another supply when you have a dead short somewhere.
After that I'm afraid the motherboard is shot.
CPU/ram/HDD's are likely OK but this sort of spike can take out anything.
Check for burn marks to the hard drive circuit boards (controller chip) a small burn pit.
Martin


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

 

[garebo]

I am wondering why you suspect the power switch as it only provides momentary power?
I believe the power supply could be gone even though it lights up the green light on the mobo.
Im sure you disabled the pc speaker from the mobo.
Can you try another power supply to rule out your power supply as the culprit?


Good advice + great people = tek-tips

 

[micker377]

Is this an ATA power supply (large mechanical switch), or an ATX power supply (small soft touch switch)? The question is because the ATA supply does have a green wire (plus the black/white/blue/brown) and the green wire is a ground. The ATX is just 2 thin wires that go to the motherboard, no ground. I can't see how the speaker lead could be involved unless you had the front panel off for cleaning.

 

[djeddiej]

Wow. quick reponse. thanks so far.

Here is a little more details about what was happening prior to the situation described in my original post.

-The computer was on, in Windows XP, actually doing a drive recovery (sadly, that was probably screwed up too), so the 4 hard drives in the system were humming.
-the side of the ATX case was facing me. It was on top of my desk. Monitor to my right. The reason I talk about the power switch is because it was lying in front of me, between me and the case, lying loose on the desk. It was connected to the standard Power Pins on the Asus mobo. The remaining wires in that area (wire from the onboard speaker, reset switch, HD LED light) were all connected and located <i>inside</i> the tower.
-I believe there is, of course, power coursing through the switch.
-The tower has an Aerogate II fan/thermometer controller..I was turning down one of the fans (had to stand up and lean in a bit to do so), the power switch moved a little bit and (I suspect) may have touched the tower or something may have moved internally as I touched the tower (a molex power cable?)...would this cause a short?
-Anyway I briefly heard a high pitch sound (perhaps the fan), smoke started to appear, I immediately looked in the tower, saw a spark (or small flame)...all may have not been in that order (this process lasted maybe a second).
-The PC shut down.

Then I did the inspection of the damage (back to first post).

The tower is a tall Acer Open Tower (I cannot recall the term to describe an extremely tall ATX tower, but it has 5 bays...). The Hard drives themselves are in removeable trays (I am hoping this reduced the chances of electronic damage) and all drives are relatively distance from the apparant "source" of the spark.

I am more concerned about the mobo and particularly, the CPU. I can replace the mobo, the PSU - they can be gotten relatively cheaply (the mobo itself was about 65$ CAN) but the CPU is well, an expensive CPU. That would hurt... :<

Anyway thanks for your advice, any additional information would be appreciated. I will be opening up the tower and taking it all apartm leaving only the PSU and mobo to start testing...



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

 

[garebo]

Has to be ATX, hes running a P4 3.2 ghz with 1 gig of ram.
But it may have ruined your motherboard as well.
With 4 hdds and all you have that is a large burden so if its a cheaper, light power supply, its likely cooked.


Good advice + great people = tek-tips

 

[djeddiej]

To answer Micker's statements -

Is this an ATA power supply (large mechanical switch), or an ATX power supply (small soft touch switch)?
-It is an ATX Power Supply. (Two thin wires).

I can't see how the speaker lead could be involved unless you had the front panel off for cleaning.
-The side panel was off so everything was exposed. The front side is a metal face with a removable plastic molding in front.

To answer Garebo's statements

I am wondering why you suspect the power switch as it only provides momentary power?
-With the power switch lying loosely (I grounded it initially when I turn it on by placing it on the tower, but then it moved around a bit) - you can "feel" the slight current in the switch if you touch the screws on the switch (of course, again I was grounded with my little wrist thingy). Of course, this may be pure halucination...

I believe the power supply could be gone even though it lights up the green light on the mobo.
-I think so as well, and if its just the PSU I am thankful (although now I have the pain of taking the PC apart...again)

Im sure you disabled the pc speaker from the mobo.
Can you try another power supply to rule out your power supply as the culprit?
-I am going to see if the other Power Supply in my my old Pentium is compatible. If so, I will just test with it and the mobo only.

To answer Paparazi's statements...
Surely it didn't just do this on it's own?
Did you trap a wire or something?
The fact that the speaker wire burned must mean it was grounded in someway.

-I may have tripped a wire. As I mentioned in my second post, the power switch was lying loose. There was a loosely hanging power cable(molex? sorry if its the wrong term) within the tower that was not connected to anything on the inside.

-The speaker wire was completely within the tower...is it possible that it may have caught on a cable tie that may have been on the power cable, caught on the onboard speaker connector as I brushed the side of the tower to test change the fan speed???

I keep on running through the situation in my head...


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

 

[micker377]

The power switch on an ATX just shorts two wires on the main Mobo power plug (of course through traces on the Mobo). If his actions did cause this (as opposed to dropping a screw into a "live" board), he might as well get a new power supply and give it a try (he probably needs one anyway). Any serious damage to the mobo probably burnt some traces, and the system won't power up.

 

[Frank4d]

Doesn't look good...

If the power supply is ATX, it has a 20-pin connector plugged into the MOBO. As a test, you can short the green wire on the 20-pin connector to one of the black wires on the 20-pin connector. A bent paper clip works well for this. If it does work, you have to leave the jumper in place or the PC will pwer off.

If it doesn't power up - your power supply is fried. That is relatively cheap to replace.

If it does power up - something on your MOBO is keeping the power switch from turning the PC on. Usually a fried MOBO or CPU.

 

[djeddiej]

Hi -

Thanks again to all who have been responding. There should be a "thank all in this thread for this valuable post" link.

In response to Frank4ds msg-

The power supply is ATX. There is a 20 pin connector to the mobo, as well as an additional 4 pin connector (mind is rusty, not sure what it is called, but plugs next to the CPU, and is not the fan connector). I am trying to understand what you mentioned about the paper clip test. Is there a link to a page with an image the demonstrates this? (I just don't want to place a paperclip in the wrong place).

In the meantime, I am going to get another power supply as my older one is an ATA power supp...not sure if that will work anyway (have to pull it out of the tower find out). Will have to do that tomorrow (unfortunately no 24 hour computer supply depot here...would be nice for us variable hour workers)



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

 

[garebo]

As a test, you can short the green wire on the 20-pin connector to one of the black wires on the 20-pin connector. A bent paper clip works well for this. If it does work, you have to leave the jumper in place or the PC will pwer off.

What he is saying is to take a paper clip and unfold it and place one end of the clip inside of where any black wire goes and the other end inside of where the green wire is. This is on the top side of the large white 20 pin main power connector that goes from the power supply to the motherboard. this takes the place of the power on\off button and does it there instead of at the on\off button.
You can use any wire that you have as well to do this, instead of a paper clip, just take plastic off both ends of a short piece of wire and place on end in top where green wire is and one end in top where any of the black wires go, that being on the top of the long white power connector. See if your power supply comes on and if your mobo will boot.



Good advice + great people = tek-tips

 

[garebo]

,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,

These are the pins in your power connector from power supply to motherboard.

There are about 7 black wires there, along with one green wire, orange, few red, blue, yellow, 20 in all.
You put the wire or paper clip in the top and push it down on any black and the green wire.

The 4 pin is only for intel motherboards and not needed for your athlon setup.

Good advice + great people = tek-tips

 

[Frank4d]

Shorting the green wire to a black wire (doesn't matter which one) on the 20-pin connector just establishes whether your PSU is good or whether you have a MOBO problem instead. If the PSU turns on, your fans should spin... and listen for beep codes that might indicate the real problem. If the PSU doesn't turn on with this test, your PSU is dead.

 

[djeddiej]

Hi everyone -

This has been a great experience in the response from this particular forum on tek-tips. I would have not known about the paper clip test.

After ensuring that no devices were plugged to the PSU, I rigged up the "paper clip", one end into the green wired connector, and the other end to a black connector.

Good news is the PSU fan(s) (there are two) came on. A little relief at that.

The not so good news is that its probably not the PSU, which leaves...the mobo, the CPU (and I hope) the switch; and perhaps anything else I have missed.

No beep codes whatsover. However, was I supposed to connect the paperclip/PSU connection to the mobo as well?

I suppose the next step is to reconnect the mobo and the PSU (with or without the paperclip? I suppose with the clip...)

I had a problem connecting the paper clip from the top side (I think the clip is too big) so when I tested it I poked it through the "pins" (the pins have holes in them).

Anything else I should look for before I try this step?


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

 

[djeddiej]

Update -

Since my previous post, I just confirmed the following:

-The PSU appears to work (paper clip test)
-Power appears to be coursing through the MOBO.

I believe power is coursing through the MOBO because
1) the Standby Power LED on the mobo is on and green
2) plugging in the CPU Heatsink Fan direct to the MOBO (it was previously connected to a fan controller) cause the fan to start spinning.

I resolved an issue that I discovered. There was a short in the power switch, where the wire connects to the switch itself. I stripped a half inch of the wire and re-connected it to the fork/terminal part of the switch where it was connected previously and wrapped it in electric tape...the power to the mobo was restored!

So on my list is to get a new switch.

Also note that I attempted to connect a new onboard Case speaker (I cannot confirm that it works, although all the connections on the speaker are there) and still not beeps.

I have a problem turning it off now (the switch does not seem to turn it off) but I can turn it off via the PSU for now as I keep testing.

I am now going to plug in a video card to see if I get a display and the BIOS.



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

 

[paparazi]

It should turn off if you hold the button in continuosly for 5+ seconds.
I think it might help to approach this with the bare minimum connected.
pull out everything (IDE cables, addon cards etc front panel header wires) just leave the motherboard with CPU/heatsink/fan, 1 stick of ram, video card and power supply.
This way you have fewer parts to think about.
Get a post first
Then onto a boot

But let's not get ahead of ourselves. clear the cmos, use a small flat screwdriver to momentarily bridge the power header pins, does it post?
The described power supply test doesn't really tell you for certain that it is OK, indeed one of the power rails could have failed and it would still pass this simple test.
I would still try a replacement PSU, your lower wattage unit should be OK with this bare configuration.
If it won't post with the new PSU and a bare config I really do suspect terminal motherboard damage.
I still maintain the CPU/graphics and ram normally are less effected by this type of failure.
Martin

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

 

[djeddiej]

Hi Paparazi -

Thanks for your assistance. Here is a (somewhat pleasant) update.

I had as you suggested, set up a mimimum system.
-1 CPU/heatsink/fan
-1 stick of RAM
-AGP vid card
-power supply.

Result: Power to mobo is on. Holding button for 5 seconds DOES NOT turn it off however. I had to turn it off via the PSU switch.

THEN - a thought occured to me. I took out the AGP card, and plugged in a PCI video card. (ATI, 16 Meg All in Wonder 128)

Powered up.

I see Post! The speaker beeped once (its alive) and with the keyboard pluged in, I went into BIOS.

The BIOS sees the processor (3.2 Ghz). Settings in BIOS appear to be OK.

I continued testing just the PCI video card in each PCI slot. Each time I got the card to run.

I then installed a IDE RAID controller card in the second PCI slot, and 16 Meg in the first...Booted successfully

I then added an older Adaptec SCSI 2940AU controller in the third slot. vid card and raid card in. success.

I then added a firewire card. screen does not detect it (it never did) but at least can still see POST

I then added the proprietary ASUS wireless Network card which fits in its funny slot. Still posted.

So does this mean my AGP slot is fried? Is it just not grounded or something?

I tested the AGP slot again, this time with an older 64 Meg ATI AGP card in the slot (I didn't change jumpers for this, I may have to), but all I got was the mobo powering up, no POST, just black screen.

I am soooo close. I am hoping that I am missing something with the AGP connection...

So in summary, so far

PSU works
Mobo has power coursing through it
Inserted both RAM slots, both active (2 x 512 Megs)
All PCI and proprietary wireless slot active
screen active using PCI video card
Able to get to POST. speaker beeps on power up (once).
Able to get into BIOS. CPU detected at 3.2 gHz

Now the assistance I need is looking at the AGP issue.
If I can get that fixed, I can hook up the floppy and run a RAM test.

Advice is appreciated, thanks again.


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

 

[Frank4d]

In the BIOS "chip configuration" menu there are options for AGP aperture size (you want 64MB), AGP capability (8X). On the "PCI Configuration" menu there is an option there is an option for Primary VGA BIOS (choose AGP video card).

If these options don't work for you, you may need to set your PCI video card display driver to "Standard VGA" before you remove the PCI card and before you install the AGP card, then install the AGP drivers when Windows starts up.

 

[paparazi]

You need an AGP4X graphics card or higher to work in your AGP2.0 slot, I doubht this older card is AGP2.0

Old AGP1.0 standard was 3.3volts
New AGP2.0 is 1.5volts

Usually you cannot get it wrong because the keyways in the cards don't normally allow physical insertion.

I would continue as you are with the PCI card, adding hardware bit by bit.

Sort out the AGP card later.
Martin

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

 

[djeddiej]

Hi again-

The video card I am using is an ATI 9200 SE 128 Meg AGP 8x card.

The specs are at

http://www.atitech.com/products/radeon9200/radeon9200/specs.html

I did run this AGP card on this same system prior to the incident, and it worked fine - it plugged in without a hitch.

I just tested the same card on another machine, and it ran fine.

I am suspecting the AGP slot itself...but not sure what to look for?

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