P4P800 Won't Power On

[greg20]

Hello,

I'm having a problem with my PC. It's not responding to the power button on the front of the case at all.

P4P800 (non-deluxe)
Antec PLUS660AMG case
Nexus NX-3500 quiet PSU

My PC was working fine yesterday. I'm posting this from my laptop. I went to turn on my PC this morning and - nothing. The AC outlet is ok. PC isn't turning on from other outlets in my house either. I opened the case - the green LED on the P4P800 is lit. All connections appear secure. I unplugged and replugged the 4-pin motherboard power connector, as well as the power and reset button connectors on the mobo (not that they would have magically jumped pins by themselves anyway...)

I didn't see any obvious evidence of a short. I had this problem a few weeks ago - I removed the front bezel and put it back on, moved some wires around in the case, and it started working again. Tried the same thing today, no results.

Is it possible the case switch is dead? I can't quite get all the way to it, but the green/white wire appears contiguous from the switch to the mobo pins.

I haven't made any hardware changes or really moved the PC since I installed an XFX 6600GT almost a year ago.

I do still have the original Antec PSU that came with the case, it was working when I swapped it out for the Nexus PSU (over a year ago). Any other possible solutions before I go through the hassle of switching out the PSU?

Thanks.

[glc]

Unplug the lead from the case switch and momentarily short the 2 pins on the motherboard with a screwdriver. If it powers up, your switch is bad. You can move the reset switch lead over and use the reset button as the power button. NOTE - it's possible a stuck reset switch could do this too, so the next step is remove the reset lead and try it again.

If it doesn't power up with a screwdriver, refer to this thread:

http://forum.pcmech.com/showthread.php?t=132409

In my experience, when you remove and replace the front cover, it's easy to knock something loose or jam the power and reset switches. They are momentary contact microswitches, depressed by tabs on the buttons.

[greg20]

Ok, thanks for the help.

Unplugged the power switch from the mobo, shorted the leads with a small screwdriver, and didn't get anything.

Moved the reset lead over, tried to use the reset button as the power button, and still nothing.

I'll see what I can find by using that thread. I was thinking of a new case but I'm not really sure that's the problem anymore.

[Cricket]

Swap out the Nexus power supply for the original Antec to see if you can at least get the system to POST with the Antec. That will tell you if the Nexus died or not.

Cricket

[greg20]

Ok, I gave that a try. I didn't physically remove the Nexus. But I removed all its wires, plugged in my old Antec to everything, turned it (the Antec) on, and I got the same result. LED turns green, power switch/boot switch/swapped power/boot leads/shorting the power leads all do nothing.

I guess something is shorting and preventing the motherboard from allowing itself to power on, or else there's something wrong with the case switch(es) and shorting it isn't working for some reason (hard to imagine why - I'm using a small metal screwdriver to short the appropriate posts. Checked the P4P800 manual to make sure they were the right ones).

I don't see how something could have moved and shorted when my PC was just sitting there all night. Looks like I may be pulling it apart to try it outside of the case, and possibly getting another case to try.

Thanks for the help, appreciate anything further.

[Cricket]

The system isn't starting up with a different power supply connected? Have you tried stripping it down to the bare minimum parts? Motherboard, CPU, heatsink, video card, RAM, power supply, keyboard and monitor? Maybe one of the drives died and is preventing the system from booting. I've seen bad optical drives do this.

Cricket

[greg20]

No, it's not starting with the known-good Antec supply connected either. BTW everything I've tried so far is with everything still in the case. When I tried it, I disconnected everything from the Nexus PSU, and connected the Antec PSU using only the AC cord, the large and 4-pin mobo connectors, and the connector to my XFX 6600GT. I didn't connect any of the drives or anything else to the PSU. They're still connected to the mobo via their IDE cables etc. The soundcard & wireless NIC are still plugged into their PCI slots. I didn't have a monitor or keyboard or anything external hooked up to it. I just wanted to see if it'd at least power on with the Antec, and then if it did I would know it was the Nexus, turn it off, and start adding things back to the Antec PSU.

Just curious, have you seen optical drives prevent anything at all from happening when you go to power a system on? You said they may prevent it from booting - I'm not near booting yet. It's just acting like it's not plugged in (except that it is, of course. And the green LED is on on the mobo).

Thanks.

I may need to try it next out of the case or in another case.

[Cricket]

Oh, I thought you had everything out of the case already. You should try that next.

If you still can't get any response from the computer with the motherboard out of the case then you may be looking at a dead motherboard.

Cricket

[greg20]

Originally Posted by Cricket Oh, I thought you had everything out of the case already. You should try that next. If you still can't get any response from the computer with the motherboard out of the case then you may be looking at a dead motherboard. Cricket

I'm afraid it might be. I've got everything out of the case now. Got the mobo on a non-conductive surface. All I have is the motherboard, PSU, 2 sticks of RAM (not moved out of their original working locations), and the 6600GT in the AGP slot. Removed the other stuff from the PCI slots. Got the motherboard large power supply and the smaller 4-pin connected, the power switch from the case connected, and upon pushing the switch, nothing happens at all. The LED on the board comes on but that's it. Also tried the power switch out of the equation by shorting the power pins again (outside of the case this time), also with no results. No fans in the PSU or the one on the CPU cooler do anything. When I was taking it apart, all the standoffs were in the right place and there wasn't any evidence of the board touching any part of the case besides the standoffs and the I/O shield, which is out of the equation now anyway.

The few times something similar has happened in a past (but never going on this long - the PC came on after 3 or 4 tries of just moving stuff around or taking the front cover off and putting it back on, which may have not been related at all) may have been leading up to its death overnight. I'm not sure it's dead yet, especially with the LED still lighting like it did before. If it is, 2 years seems like a pretty short life for a mobo; although this was my first build everything has gone more or less well until now.

Thanks, appreciate anything else you can suggest.

[Panama Red]

That 6600GT is a relatively new vid card. Did these problems happen before you installed it or only after? You might want to try a different vid card and see if that's it. Also, try just one stick of memory at a time. Lastly, the good news, if it is the mobo you should be able to get it handled under warranty. Asus mobo's carry a 3 year warranty.

[greg20]

AFAIK, these issues have only been occurring since I installed the 6600GT. But, I have to say, that was a year ago, and it wasn't like I started having problems as soon as I installed it (and anyway, it's been VERY sporadic, only occurring a few times, and this is by far the most 'un-easily-fixable' so far). What I mean to say is, no, I don't see any direct correlation between installing the 6600GT and then suddenly having problems. It didn't happen that way at all. I've been happily chugging along with the 6600GT for months prior to this. It could be related, but it seems like a stretch (not to say that I don't appreciate the suggestion, I do!)

I don't have any other AGP cards but I've got a PCI card that was also in there, an old Radeon 7500. I'll try that on its own. I was running a triple monitor setup that way for MS Flight Simulator 2004 - I've got things much more back to basics now as I said before, out of the case.

Thanks for the memory advice, I'll try that in a bit.

Regarding the warranty, yes it is 3 years, and I've only had the board about 2 1/4, so that's very good. However, on the Asus site it says to 'contact retailer' for motherboard returns, and on Newegg's site it won't let me get anywhere with the RMA because I'm outside of their 1 year warranty on the parts I ordered for my system in August '03. If I do have to return it, any suggestions on who to contact regarding that?

Thanks so much for your help.

[Panama Red]

Just contact Asus Tech Support. The "contact retailer" is just for the first 30 days I believe.

[greg20]

Ok, well now I'm just about positive that it's the ASUS. Out of the case, nothing external connected, just mobo/cpu/cooler/memory/vid card/PSU power connectors.

I get the normal green LED and then nothing happens when I push the power switch (when I have it connected) or when I short the pins. This happens on both PSUs, the Antec and the Nexus, and I know positively that the Antec is good and the Nexus seems ok.

I tried removing the 6600GT from the AGP slot and putting my Radeon 7500 in a PCI slot; same results. Also tried just one stick of RAM at a time in each of the one-stick-only config slots and that didn't change anything.

So I think it's time to contact Asus about an RMA.

Thanks.

[Panama Red]

Think you're right. At least now ya know.

[greg20]

Thanks, you guys helped me zero in quickly on the problem. Just became a PC Mech supporter thanks to your assistance.

I called Asus and they also had me remove the processor to make sure that wasn't preventing it from powering on. It wasn't, so I got a case # and an RMA to send out on Monday.

[blue60007]

Well removing the processor would garuantee the system not to power on.

[greg20]

Hmm, could very well be. Relaying what the tech told me to a friend, he told me that a system he had (don't know what) would power on momentarily without the CPU installed, and the fried CPU he had with it would prevent it from even doing that.

[Cricket]

Originally Posted by blue60007 Well removing the processor would garuantee the system not to power on.

Actually that depends on the motherboard. Some will just sit there dead, others will give you some kind of audible warning (wailing tone, long beeps, etc...).

Cricket

[greg20]

I just wanted to follow up on this thread, now that I've resolved the issue. I ended up RMAing the P4P800 to Asus and a component had died, so they replaced it. I got it back today - about 3 1/2 weeks door to door on the RMA. I hope this will help someone else having a similar problem in the future.

[Cricket]

Thanks for the update! Glad you got your computer going again.

Cricket