Wacky on/off issues w/ Asus P5W DH Deluxe...

[wahnula]

Howdy folks,

My P5W DH has been serving me well the past 18 months or so...with an annoying quirk. It will turn itself on at the slightest provocation, like a mouse move, or unplugging USB cables or devices from it while it's turned off. No biggie, I know...just turn off the PSU when the machine is shut off.

I've been through every corner of the BIOS to make sure all "Wake On" features are disabled with extreme prejudice, even cleared the CMOS and double-checked the settings.

PSU: Nexus 450 Watt
CPU: E6600
OS: XP Pro, Vista, & Ubuntu
GFX: ATI PCIe 9750 XTX


This wouldn't be so much of a problem except recently I got a new case and in the process of moving in I've discovered more power on/off quirks. When first assembled, it powered up first time.

Since this case has a mainboard tray, it's super-easy to work on. I decided the HSF was pointed in the wrong direction from my previous case, so I removed the m/b, re-oriented the HSF, re-connected everything, hit the power button and...nothing. No fans, no beeps, nada. The little LED was lit on the m/b. I removed the switch connector and shorted across the power pins...still nothing. On the verge of a breadboard build, I tried a last gasp, pulling the plug on the PSU and holding the power button for 30 sec. or so...and the PC came alive!

Last night, I needed to replace the AS5 paste on the HSF (ran out previous day, temps were warm) the whole operation took 15 minutes. This time, started right up. I was greeted with a beep every second or so, and realized I had neglected to connect the six-pin PSU connector to the gfx card. I reconnected the cable, now it will power up but no POST, no BIOS splash screen, no reduction of fan speed after a few seconds, no beeps, just all fans working. The 30-second trick did not work. I thought I might have damaged the PSU or GFX cards, or scrambled the CMOS. I cleared CMOS and tried again...same, fans come on, no POST.

Sensing PSU or GPU failure, I tried a breadboard build with a know good PSU, no HDDs, no GFX, no nothing except CPU, RAM & m/b. When I went to hit the I/O on the PSU (remember there is no case switch connected) the PC came to life with the same symptoms. I re-connected the GFX Card and the old PSU and it was the same.

Thinking I might have damaged the CPU when I re-seated the HSF, I removed the CPU, gave it a good blow-off, wiped down the top and re-seated. This tine it worked. So, I replaced everything in the case, no power up. I shorted across the pins with a screwdriver, now it starts, boots, runs fine. I replaced the power switch plug and all is currently well.

I can't help but think the weird on/off situation was somehow at the root of all of this. It did the same thing in the last case too. Any ideas! Thanks folks.

Tony

Users helping Users...

 

[BadBigBen]

could be a wacky mainboard or a loose connection...

and frankly Tony, you did all the homework I would have done...



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[G0AOZ]

Tony, since you're still suffering from the same symptoms in this new case as you were in the old one, itemise the components you have moved across. I am unsure from your description as to whether or not you now have a completely different PSU in the new case. If you're using the same one as before, then that could also be a prime candidate along with Ben's suggestion of the motherboard itself.

ROGER - G0AOZ.

 

[wahnula]

Yes, the PSU is the same. I've been thinking about swapping it out as the case's layout is such that the PSU is sitting sideways, and a bottom-fan PSU has the fan about 1/2" from the case's side panel.

The components I moved across were the MB/CPU/HSF, PSU, HDDs, optical drives, floppy drive, card reader and fans. I have some new mobile racks for the HDDs, with blue LED displays (cool!) and a new fan controller that I have not connected yet.

While a PSU could be responsible for the power-up issue, it doesn't fit the symptoms of the auto turn-on, which I experienced with a different PSU as well. Which leaves the mainboard. I guess I can live with it, but I would sure like to know why?

It's not a good feeling to wonder if the system will turn on after maintenance. Of the dozens of PCs I've built, this is the only one where I hit the button and nothing. I pride myself on getting the MB headers right the first time, or at least by the second time .

Was there any chance I did some damage by powering up without the graphics card power connector? I would think not, I know it's a common mistake. And, it's an X1950, not 9750.

Tony

Users helping Users...