what have I done?

O

omicron

Weaksauce
Joined
Mar 7, 2004
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My girlfriend's PC had an insanely loud stock CPU fan on her old p4 2.8ghz. So I bought a Zalman heatsink+fan (CNPS7700) and installed it on her mobo. The installation was ridiculously difficult and the product just did not sit well on the CPU due to design flaws. The screws that screwed it into the bracket seemed like they were too long and touched the mobo (they aren't supposed to).

Well after the heatsink install, the computer power LED displayed blinking red, and the computer shut off instantly. BUT, there was still the boot up picture on the monitor, it would just cut out everytime I tried to power it on. I tried powering it up 3 more times, nothing. I then looked inside the computer to see the HSF had dislodged off the CPU.

Worried, I properly installed it yet again, and this time when I powered it on, I get a green light from the power LED. However, now there is no picture on the monitor, no signal sent to the monitor, the computer won't post at all.

I tried to reproduce the red light scenario by unscrewing the HSF from the cpu brackets and letting it just sit on top and I can't get it to do that again. Also, I've noticed that one green light is on on the mobo, and another is on at the back of the power supply.

My question is, what have I done, what needs to be replaced or troubleshooted? It's honestly Zalman's poor design that caused this, and I'm never buying their products again, but that doesn't really matter.

It is possible that a foreign piece of metal that held the HSF into place touched the mobo while it was on. Would this permanently damage / short the mobo? I've tried resetting the CMOS.
 
I've used numerous zalman products and have never had an issue. Ever.
You sure you got a model that was compatible with your socket type?
I don't see how it's zalman's fault that you didn't put it on right the first time and ended up frying something b/c you kept turning it on repeatedly.
 
The 7700's weren't that hard to put on. If memory serves me correct, there should be only 2 screws into the backplate. You screw the first one in a little tiny little bit so it holds, and then the other one in which takes a little bit more downward force. Then you take turns tightening each side a little at a time. Under no circumstances do you over tighten it.

So what happens when you put the stock heatsink back on with thermal paste? This should be the first thing you do.

Man, your girlfriend is probably pissed you broke her myspace. No facebooking for awhile.
 
omicron said:
It is possible that a foreign piece of metal that held the HSF into place touched the mobo while it was on. Would this permanently damage / short the mobo? I've tried resetting the CMOS.
Click to expand...

Did you see anything touching before you re-mounted it? Did you use to much thermal compound? If the screws were touching the mobo, did you keep screwing them into the motherboard cracking it or a trace?

I would start by putting the stock cooler back on with the proper amount of thermal compound. If this does not work, i would say that the screws or some part of your install damaged the motherboard. Start by looking in your motherboard manual and see what the 1 red light code is...

gl and always Quadruple check before plugging the power supply back in!!
 
This is why i try never to work on my girlfriends PC unless they insist. :) Hope you get it sorted out.
 
omicron said:
The screws that screwed it into the bracket seemed like they were too long and touched the mobo (they aren't supposed to).
Click to expand...

this could be your problem... did you see or smell the magical white smoke? you know the computer needs it to run don't you? when you let it out it can't work anymore.
 
Sounds like you may have damaged something. How long did you leave the CMOS battery out? Did you reseat all the components (RAM, GPU, etc...)?
 
1) I used the old thermal paste. Would this really prevent POST? It doesn't get that hot that quickly. Even if I go buy arctic silver now, why would putting paste make the PC post?
2) Upon first powerup, the monitor displayed the bootup "HP" picture, and fans had power, but it would cut out instantly.

-I then turned the computer around to see why it was cutting out, and there is the heatsink, the rails had slipped out of the bracket and one of the (metal) silver rails was touching the mobo. This is on a socket 478 so the 7700 doesn't install through the backplate, it installs through 2 metal rails. What happened was the rails slipped out and were touching the mobo when I was powering it on.

I reseated the HSF - more securely this time. I don't see any marks where the screws may have touched the mobo, I don't see any marks where the rails may have touched the mobo.

After reseating the HSF, the computer powers up but no image on the monitor, it doesn't cut out but doesn't display anything.

Furthermore, I was able to reproduce the original power down error I got by unplugging the 4 pin CPU connector and starting the PC. The red light turns on and the PC instantly powers down. Does this mean I shorted power to the CPU / Mobo, therefore damaging the mobo?

Other things I have tried:
1) Removal of all memory. PC starts but no beeps. Fans have power.
2) Reseating of all connectors.
3) Installing stock HSF again.
4) Removing CMOS battery for 30 seconds.
5) Inserting a different socket 478 CPU.
6) Unplugging HDD. PC produces no beeps.


So pretty much have we narrowed down that I either shorted my Mobo or PSU? How do I more accurately find out what the culprit is to replace?

I know for sure that the HSF slipped off and was touching the mobo the first time I powered on.
 
she's annoyed and pissed but we're long term so it's not a catasrophe. i have an extra laptop to lend her, im just gonna have to troubleshoot this which is gonna take a lot of time.

also i'm gonna have to back up her SATA hard drive somehow, and i don't have a desktop to do this =/
 
CanesVenetici said:
I've used numerous zalman products and have never had an issue. Ever.
You sure you got a model that was compatible with your socket type?
I don't see how it's zalman's fault that you didn't put it on right the first time and ended up frying something b/c you kept turning it on repeatedly.
Click to expand...

see that's the problem. this heat sink should not be advertised by zalman as compatible with socket 478, but they did it to increase market share. when i found the manual online, socket 478 isn't even listed, because they probably had their translators create the manual before they added socket 478 "compatibility" and by compatibility i mean two shitty little metal rails that very loosely sit in the stock HSF mounting bracket.
 
It could have cut a trace on the mobo, broken a resistor, knocked a cap or inductor loose, etc...
Shorting is possiblity.
Do you have another PSU to try?
 
To eliminate the possibility of shorts, take EVERYTHING out of the case, blast it with compressed air. Power the system on outside of the case. You want to eliminate the possibility of a short the screws from the heatsink are creating with the case. I've had this issue before and it causes all sorts of weirdness.

Btw, did you happen to have the screwdriver slip and fall onto the mobo? Happens to the best of us.
 
omicron said:
she's annoyed and pissed but we're long term so it's not a catasrophe. i have an extra laptop to lend her, im just gonna have to troubleshoot this which is gonna take a lot of time.

also i'm gonna have to back up her SATA hard drive somehow, and i don't have a desktop to do this =/
Click to expand...

Don't know if you have the cash but you can buy cables to connect the sata hard drive to the laptop via usb,
 
after school today, i am taking the mobo out of the case. is there a specific way that i can find out whether this is 100% a mobo issue, or 100% a psu issue? i don't have a second psu laying around to use, since i always ebay my excess tech stuff.

also, if i take the memory out or HDD out and the PC won't beep, does that pretty much indicate 100% mobo / psu issue?
 
Your computer will need RAM to POST, so make sure to leave that in. There's no 100% way to find out which part is bad without access to excess hardware to test each part individually.
 
thanks, appreciate all of the advice. i'll do further troubleshooting tonight and fill you guys in. my hunch is that when the HSF touched the mobo, upon power on the mobo kept shorting (and thats why it shut off 3 times). after the 3rd power up the short probably damaged the mobo.

i can reproduce this exact event by unplugging the 4 pin cpu power cord. i'm not exactly sure the significance of this but basically what it tells me is that something (the metal piece) was shorting power to the mobo / cpu when i powered it on.

i should've inspected upon the 1st power up. oh well, live and learn.
 
yeah, the main thing is if you do a hardware change and it doesn't boot. immediatly stop and inspect everything, because you missed something.
 
sup guys.

so i looked at the mobo closely in the daylight, and where one of the screws connected the HSF to the mobo, there is a scour mark on the mobo exposing gold underneath the green.

since i'm assuming this cannot be soldered or humanly fixed, i ordered the identical mobo off ebay so as not to have to reformat. $50.00 down the toilet :(

so it didn't happen because the first time i didn't screw it in tight enough and it fell off, it happened because the 2nd time i screwed it in too tight. never buying zalman again in my life, this is why i have always stuck with thermaltake. no shitty jury-rigged installs of 500 LB copper flowers.
 
You may have shorted something on the MOBO when the screws touched it. I have used Zalman coolers for many builds and have never had a problem but there can be no shortcuts, it must be done correctly. And, what is this about using the old thermal paste? You did clean off the old thermal material completly and then use new material right????
You may have not had contact between the heatsink and the CPU heat spreader. In fact you may have fried the CPU is there was no contact.
 
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