Please help tech savy me diagnose laptop

The short story: Nephew gave me his not working laptop.

Press power button, the fan comes on, then turns off, and the LEDs stay lit. Nothing else happens.

If I press fn+esc the laptop stays powerd up, but it makes no attempt to read the USB floppy drive. It does try to read the dvd drive when it's installed and fn+esc is pressed, and I'm pretty sure I made a good cd boot disk with the BIOS and flash program on it.

Ok now the long story, this laptop tried to boot windows, then went black screen. So I tried safe mode and it would stop on the same file every time. So I decided to do a fresh install of windows. But it would go black screen after 5ish minuets.

I put the UBCD in it and the comp would freeze no matter which test I ran.
Finally it you freeze, or black screen in the middle of post.
Then it would start the fan for 2 seconds and shut off.

So I stripped it right down to just the mother board (as per tech manual instructions), nothing else attached. Redid the thermal past with arctic silver. And it would still turn on the fan for 2 seconds then stop.

So, what could be wrong. Like is the board toast, anything else I can try or do?

Thanks for reading.
Ronan.

 

did you try replacing the memory?

 

Iit's an acer 3350 I forgot to say. I have an acer6930 for work. I put the memory in the working laptop and tested it with UBCD. Both sticks were good. And the 6930 boots up with the 3350's memory.

 

It could be a dead HDD since you were able to get to windows. It could also be a dead video card as safe mode usually gets you to non accelerated video.

 

HDD did fail the UBCD test. So I pulled out the HDD.

It should still POST with the HDD pulled out. (right?)

Right now it doesn't seem to POST.

By my understanding a computer, or laptop shold give POST errors, audio or visual with every FRU disconnected.....right? So when I stripped it down to just the motherboard, I hoped that it would post, and then I would add back the components till I added the one that failed to POST.

But that never happened.

I'm applying desktop knowledge to laptops. I'm not sure if all the same knowledge transfers over. At the point I'm at, I'd just replace the motherboard, But golly, laptop MBs are expensive. So I thought I'd ask you pros.

 

Try holding some other buttons while turning it on.
Try ~, TAB, FN, |, and every other button.

There should be a diag mode, and if you had the diag disk you could do some really low level tests.

 

I tried pressing lots of buttons while powering up. no difference. I think it's a hardware problem.

Thanks for the suggestion. What else can I do to narrow down the search?

I need to try to find out why it won't post.

This laptop sputterd out. So it was a slow blow component. So which component. I stripped it right down to the motherboard and it still wouldn't post. What I don't know is, if this unit was working, would I hear the error beeps if it was only the motherbord powering up?

Please help solve this mystery. If I fix this laptop, it'll be the first ever laptop that I exclusively owned. I can't keep personal stuff on a work laptop. You know what I mean? Not to mention it's the fastest computer in the house right now. If it worked.

What I really mean is that I appreciate any help from you guys.

 

check the mosfets.

look for anything that seems odd.

How's the CMOS battery, is it near 3V?

Look for any shorts, any pins bent or touching each other.

 

CMOS battery is stone cold dead.

OK really? A dead CMOS battery will prevent this laptop from POSTing? Dead batteries in desktops will still boot. hmmmmm.....

The battery is soldered on the board. I'm no stranger to soldering, but where do I get a battery with the tabs on it. Any idea the spec of the battery? 3V and what else?

 

Actually I'm not even sure it's 3v.

Doesn't it have something written on the battery?
Try to get a replacement.

Or you can even recharge that old battery.

I think some notebooks dont boot without a good CMOS battery.
Not 100% sure though.

 

CMOS battery is a Sanyo ML1220 3v 15mAh rechargable.

Says so right on the battery, under the cold soldered tab, which I pryed off hopeing to attach a cr2032. But now I'm wondering if it really recharges? If so, then wouldn't a 2032 pop if I used it?

 

Just recharge the original battery by itself.

I have done it before.
Be carefull though.

 

Opps, I had the multimeter set wrong, the cmos battery is at 3V. Not so tech savy after all.

And now that I have the laptop stripped down again, I don't see anything obvious. I wish I could swap with known working parts, that is what they teach the techs to do.

now what? I guess I need a magnifying glass.

(shouldn't a tech savy guy have one of those?)
oh shudup..

But hey, I love messing with this stuff. I'm having a blast.

 

ha, I feel stupid for not asking the specs of this thing.

What GPU?

Did you try an external screen, does it beep, any lights?

 

let me guess, 9600M GS ?

I think I found the problem.

That GPU has a known fault. Just google it.

The solder cracks, then it has a bad connection to the motherboard.

Simple fix:

Buy a heatgun from the hardware store (used to strip paint).
Set it to 300C.
Heat up the GPU for a min.
Test it.

There are many youtube videos and sites explaining the details.
Please read and watch them first.

Make sure the motherboard is lead free.

Look up BGA reflow, BGA reball, BGA rework.

I will post some links for you.

EDIT: It's hard for me to find the specs of your notebook.

But these links might be interesting for you:
http://forum.notebookreview.com/showpost.php?p=4792475&postcount=15
http://cegeekbook.blogspot.com/2009/11/dv6000-no-video-no-wireless-issue.html
http://www.hplies.com/viewtopic.php?f=2&t=497


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I know all about GPUs becoming unseated. This is why Xbox 360's RRoD. I fix them for my friends. The one fix you post is exactly the same way to fix a 360 GPU. Take the heat sink off and overheat it. So I know the process all to well.

External screen does not dispaly a thing, the laptop screen flickers for a millisecond when I power it up. The fan starts and stops. the LEDs all stay on, when I press the FN+ESC, the fan stays on, but will not read usb floppy.

The GPU is AMD Radeon IGP (ATI Mobility Radeon™ HD 3200,3470 or 3650?, says 0817 p49352.00 216-0674026 On the chip)
AMD Turion Dual-Core Processor
AMD M780G Chipset
What else?

Ok so do I melt the GPU? Or is the silly putty on the GPU not doing it's job and the GPU overheats in an instant, and the comp shuts right down? Maybe I'll put some paste on and find out.

update: I tried paste, I tried paste and a penny, neither worked. Then I tried letting it cook with heatsink off, no luck. No I will look for my heat gun and read some more

 

wait, dont heat it up.

nvidia chips are bad, ATI is ok.

you probably have a different problem.

 

Too late, I heated the crap out of it.

But I didn't wreck anything. And it's still the same. But now I'm inspired to take the heat gun to this 360 that won't stay fixed.

But get this. When I had the heat sink off, and the CPU in. I turn it on, the fan starts, then stops. Then after a minuet, the fan starts up again and stays running. So it knows the CPU is too hot ( i'm guessing) So there's still life there. Just won't post or beep or video.

It frustrates me like a car that won't start, but it's firing.

P.S. Thaks a tonne for your help so far. I love googling the different leads you come up with. I've learned quite a bit here.

Update;


Ok what the hell? I put back the heat sink, taped up the cmos battery (checked with meter to confirm tape job). Then I pluged it in an started it. Fan starts, then stops, then starts again and stays on. (huh?)

So then I plug in the usb floppy, turn it on again and the light flashes on the floppy.

So I carry it over to the monitor (just the MB with keyboard and memory attched) I plug it in to the monitor and it passes post, says f2 setup, f1 continue. but nothing happens when I hit a key.

Turn it off and try again, it gets halfway through post and freezes. try again and it's back to black screen with no fan. I let it cool right down and same old problem.

RrrRRR cough sputter, rrrrerrrrerrr, cough cough cogh sputter sputter.............

what did I wiggle? what do I wiggle?

 

Funny thing:
I have a tecra M9 that acts the same way. pretty much exactly as you describe.

We might have the same problem.

 

I have a somewhat similar problem with my Dell E1705. It will turn on with blank screen with no POST, fan on/off, etc, but it does give me a RAM error LED code though. I simply swap RAM sticks around and push (pretty hard) on the RAM slot and it fixes the problem for some time. I had to do this operation about 8 times now and finally I took it apart yesterday, re-tightened the screws, etc, and so far it seems the problem is gone. I will do the heatgun method if it starts acting up again
Also, check if CPU/GPU fans are working and properly connected. It may not want to boot (although it did show a fan error message for me) if it detects that fan is faulty/not connected.