Dead laptop - double check

[MobileTechie]

I'm working on a dead Dell laptop.

On attempting to turn it on, the green power light comes on for 3 or 4 seconds, there is a quiet click sound and that is it. It's the same with the power supply or battery and any combination of the two. The PSU is putting out the right volts as is the battery. I've tried a known good PSU too.

I've stripped it down to the mobo and rebuilt a part at a time - same result.
I've tested the HD and RAM in another laptop and they work find.
I've put known good ram, HD, chip and CMOS battery in and same result.
I've checked the lid switch and it's fine.
There are no marks or blown caps on the mobo.
No power gets to the network adaptor or USB ports
The power coming out of the jack assembly is correct.

I'm obviously assuming it's a dead mobo.

Have I missed anything? I've reported my opinion that it is a dead mobo but I have a few days before it is picked up so if there is ANYTHING left to test I can do it now.

Any ideas?

 

[NickCat11]

I would conclude the same thing with everything you've tried. There really isn't anything left to check.

 

[ComputerClinic]

Yeah it sounds like a dead mobo. I understand the feeling of wanting to be completely sure. Every time I conclude that its a motherboard problem I feel uneasy about spending the money on a new one. But if you've stripped it down to just the motherboard, and a stick of working RAM, then its the motherboard.

 

[MobileTechie]

Yeah it sounds like a dead mobo. I understand the feeling of wanting to be completely sure. Every time I conclude that its a motherboard problem I feel uneasy about spending the money on a new one. But if you've stripped it down to just the motherboard, and a stick of working RAM, then its the motherboard.

I know this really but I always get that uneasy feeling when I have only been able to deduce the problem negatively rather than positively identify it. In my bad dream the customer takes it somewhere else and they immediately get it running because it's something I've missed!

 

[ComputerClinic]

What really bugs me is the SLIGHT chance that it could be the processor and not the motherboard. Apart from replacing one or the other, there's really no way to be completely positively sure its the motherboard, only fairly confident because processors rarely fail. Still, I would love to learn how to repair motherboards. To be able to pinpoint what has failed on the motherboard and then fix it would make me feel like super tech.

 

[studiot]

Can you not check the processor with a laptop post card?

Some post card manufacturers also make socket specific motherboard testers that plug in instead of the processor.

 

[ComputerClinic]

Can you not check the processor with a laptop post card?

Some post card manufacturers also make socket specific motherboard testers that plug in instead of the processor.

This is the second time someones mentioned these to me. Could you possibly post a link to a good one? Do they work with all makes and models?

 

[trapped]

I'd also be interested in pickup a POST card if there are any recommendations. This one looks pretty reasonable, http://www.pc-diagnostics.com/pc_diagnostics_tools/Motherboard_test_card_combo_pack.shtml.

 

[NickCat11]

I'd also be interested in pickup a POST card if there are any recommendations. This one looks pretty reasonable, http://www.pc-diagnostics.com/pc_diagnostics_tools/Motherboard_test_card_combo_pack.shtml.

A couple years ago I bought a diagnostics kit from this company and personally I wish I hadn't. Their customer support was horrible. I also bought their post card for desktops and it's very difficult to read even with the instruction booklet. Maybe someone else here had better success with them but I would stay away.

 

[ComputerClinic]

What about these two? The first one is really cheap which makes me questions its quality. But if anyone's had experience with either of these two I would appreciate your comments.

http://www.sourcingmap.com/usb-test-analyser-post-card-for-desktop-laptop-p-31795.html

http://www.amazon.com/gp/product/B001O7CLM8

 

[MobileTechie]

I could be wrong but AFAIK most of these things just test the POST code. So it needs to be getting to POST to begin with.

With most PCs you get beeps which tell you the POST status anyway.

So other than giving you a numerical alternative to POST beeps - I'm curious as to what benefits they offer. The adverts don't seem to specify exactly what problems they can diagnose.

 

[arrow_runner]

FWIW, I've found 2 bad Intel Celeron CPUs in Dell Inpsiron 1XXX model laptops.