Dell XPS m1730 powers up only when it wants to

[Th3_uN1Qu3]

I've got this really intriguing piece of hardware here. A Dell XPS M1730 with dual 8700M GT SLi. There was a label from 2010 underside the keyboard, and the video card PCB (what's visible of it, didn't take it apart) looks like it's been heated - it's likely been reballed back then.

The trouble is that it doesn't power up. Or, to be specific, it doesn't power up fully. All voltages come up, but the red lights don't turn on the touchpad, speakers and screen frame, i only get the power light. Every once in a blue moon all the lights will come on and the machine will work fine. When the red LEDs don't come on, it doesn't give off any codes either. It will, however, give the right codes if i remove GPU or RAM, so those seem to be okay.

I was able to force a BIOS update by holding the End key and inserting an USB drive with the appropriate file. Seen it boot in the updated BIOS, it even made it into diagnostics and ran that for a while, so we can rule that out. One thing i think is worth mentioning is that if i slap the palmrest, it has more chances of powering up fully. I can also make it hang (when it does start) if i slap it harder. So it appears to be a cold joint somewhere, but i'll be damned if i can figure out where it is.

[heavymachines]

Re: Dell XPS m1730 powers up only when it wants to

continuity test should help point out breaks in connections due to cold joints...just fixed a asus republic of gamers 2 days ago, had a micro crack you could not see at the dc jack....

[Th3_uN1Qu3]

Re: Dell XPS m1730 powers up only when it wants to

It's not any of the simple connections, that's for sure. But anyway, i think i've gotten to the bottom of this. Discovered it by accident, of course. I plugged the GPU in with the machine turned on, and the lights went on, but no video of course, as the GPU should have been initialized earlier. Power off then back on and the lights stayed off again.

Pressed hard on the GPU around the connector area, where it even says "PUSH HERE". Ta-da, we got lights and video. And starts every time now. So what's bad is the stupid proprietary connector between mobo and GPU. Gonna give it a good clean, and if it still acts up, i'll resolder it on both sides.

What's worrying me is that it doesn't get into diagnostics anymore when i press F5, it gives a sequence of trills, beeps and keyboard LEDs that indicate that both mobo and GPU are bad, but i find that hard to believe, and it could very well be some dodgy contact in that same connector. I don't have a spare HDD so i'll go get one, install Windows on it and run some tests.

[Th3_uN1Qu3]

Re: Dell XPS m1730 powers up only when it wants to

Got the diagnostics figured out. The internal LCD is not in my possession right now, and it gets stuck at the LCD/inverter test unless i start it without the external monitor plugged in and press Y (for yes) every time i hear the trills/beeps sequence. After that, i can plug in the external monitor and get video, and run the remaining tests.

I've also resoldered the GPU side of the connector. Seems to be working great now. It boots Win7 setup off USB just fine. Time to go get the rest of the parts, assemble everything and install Windows.