HP Touch Smart, possibly with a dead mobo

[Skymountcs]

Hi everyone, I'm at work trying to fix an HP TouchSmart 300-100 and it was originally diagnosed with a dead HDD. The customer approved us installing a new HDD and a Windows installation, after installing Windows I came back to find it on a black screen with the fans spinning, ODD access light blinking, and the power button flickering. It does this when rebooting.

I reseated the CPU, tested RAM, checked all connections, ran HP diagnostics, and everything seems to be fine. I don't have a PSU of this type to test with but the voltages seem to correct.

Now after calling the customer, I cleared the CMOS and the thing booted right up and let me continue installing windows, finished installing updates and rebooted. Same problem again. No POST.

This is definitely a MOBO problem right?


EDIT: This just in... The PSU light on the back is blinking, I need to find a better way to test it.

 

[Romaniac]

Multimeter; though I think those small, portable PSU testers are definitely useful as well.

 

[Skymountcs]

I used a multimeter when I tested it the first time and I was getting readings that seemed correct, but I'm no professional at it. Especially because it is a smaller 19 pin ATX connector, so I couldn't use our PSU testers anyway. Sometimes the PSU light is on and sometimes it is running off. Is this always an indicator that something isn't right with the PSU?

 

[Romaniac]

Hmm, I wonder if the power plug can still fit into that PSU tester.

Are you sure it's a 300-100? Not 300-1000? Need exact model.

If you have access to the PSU, you may try looking at these steps -BE SURE YOU click the "Power Supply turns on or flashes" at the very top of the page. Don't start with "Find the Max power rating".
http://h10025.www1.hp.com/ewfrf/wc/...g=da&lc=en&product=4007375#bph06788_section_2

 

[Skymountcs]

Hey sorry it is model#100-1120 actually.

 

[Romaniac]

Then the "light turns on or flashes' section I posted above, still applies according to HP.

 

[ShinyTech]

Have you checked the capacitors on the motherboard? Also check the BIOS and change the hard drive setting to compatibilty mode or AHCI (change it to whatever one it is not at the moment) and do a reinstall again. I found some computers are picky with this especially if its a factory reinstall from manufacturers media.

 

[chrisappleby]

Touchsmart 300 no boot, fans on loud

I have a similar problem to this one. Did you ever get a resolution?
Mine was brought in by a customer 2 months ago. It is a Touchsmart 300-1015uk with an integrated AMD GPU (i.e. no PCI GPU installed).
It will not boot to BIOS, nothing on screen, the fans come on loudly after a few seconds and stay on. No faint inverter image on screen. PSU light stays on. Only other sign of life is a blinking light on the small USB board above the mobo.
So far I've tried BIOS reset by removing CMOS battery, hard power reset, disconnecting various/all mobo cables. Capacitors look ok.
From reading various repair reports, these systems seem rather trouble prone and parts are hard to source. Parts reliability is therefore a possible issue.
I've so far tried 2 replacement mobos, a replacement PSU and 2 replacement CPUs. In whatever combination I try them I get the same symptoms.
The customer is understandably getting impatient and unless I can resell the parts I've tried so far my profit ill be near zero!
It's turning into the repair job from hell!
Any ideas anyone?