notebook dead, probably bad GPU or NB or SB?

Hi,

I bought a notebook recently. It's a toshiba tecra M9.

I bought the notebook on ebay.
The seller said it was dropped, worked for a few days and then died.

So now I have the notebook, I tried to turn it on, there were lights (power, charging and on).

But there is no HDD activity, the backlight doesn't turn on and the screen shows nothing.

The DVD drive works though (not sure if this means anything).

I took it completely apart. I couldn't see any problems visually.
I re-seated every cable/connector. Changed the thermal paste.
Also reseated the CPU.

I tried lots of different ram in both slots, I tried on AC power and on battery.

I left the BIOS battery out for 30mins.

Still when I put it back together it doesn't work. I can't even get into the BIOS.

It has a quadro NVS 130m graphics card. I think it is one of the faulty nvidia cores.


When I turn it on, I can feel the CPU getting warm.
There is no fan activity.

A notebook repair man said it's likely to be the GPU, NB or SB.

The GPU is soldered to the motherboard, so I can't replace it or try the "oven trick".

Also strangly when I plug in the AC adapter, the notebook turns on without me having to press the on button (but it doesn't work).

Anyway, I would like any suggestions for how to fix this without having to buy a new motherboard ($600 AUD for one).

I was thinking of using a soldering iron to heatup the GPUs heatsink, hoping that the solder will melt and fix itself.

I'm really out of ideas, so any help would be really great

 

I got nothing but interesting project you got. Surprised you've done pretty much every step possible.

So you're saying its not displaying anything? but turns on? or it turns on but doesnt display and nothing really happens, like fan whirrin hard at while loading bios and os.

maybe try plug in external monitor if it seems to be doing something

 

Return it to the seller, and/or file a complaint about it. Dropped should not mean 'dead within days.'

 

right

yep, nothing happens.

External monitor shows nothing

I think I explained it badly. The notebook was sold as faulty.
The seller said she dropped it, after that she used it for a few days and it broke. Then she put it on ebay.

I thought it was an easy fix, because the seller said lights came on. And the photos showed pratically no damage so I though it must not have fallen from too high.
Also I was pretty sure toshiba had said that it should survive a fall up to 1m.

Anyway, I got it for only $200 AUD so it's not bad for the price.

I would just like to fix it now.

I was hoping someone could help me diagnose the problem.

Here is more info:
Lights come on even when there is no ram in it.
There is practically no activity, apart from the DVD drive spinning.

The battery is charging. CPU, GPU and NB are getting warm after I leave it on for a while.

 

I just found this info:
http://simonrules.com/?p=15

and this vid:
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You can get a new mobo for $300-$400 or maybe find a working similar model that is otherwise damaged for cheap on Ebay.

 

Yes, that is the best way to do it.

But for now I will try the fix with a couple of heat guns.

 

One other thing... I found out that Toshiba authorized service centers get better pricing on components so for the difference that you pay and they pay for new mobo you can have them install it.

I know you like to tinker and wont consider that as an option as the reason you probably bought a broken lappie in the first place was to have something to tinker with.

 

good points. yeah i'm sure he'd want to try fix himself first. Good luck with that and hope it works. even if not. if u want a spare and dont mind forkin ~$300 for whole new MB (which i'd say pretty much same as getting a brand new laptop - if its That cheap) then yeah

 

I had my desktop do that... electricity flowing to components (and fans on - but desktop fans always run - only laptop fans stop.) It turned out it was a bad motherboard on my desktop.

Since this laptop was dropped, it could be hairline cracks on the motherboard. Once you get flex or a crack on a board, it's pretty much dead.

Does the system beep or show any diagnostic information/light patterns?

 

No beeps, or any noise at all.

There are lights:
The "on" light.
The "AC power plugged in" light.
The "battery charging" light, but the battery doesn't seem to actually be charging

Also the DVD drive light works.

The first time I opened it i saw a screw jammed between the motherboard and a metal part of the chassis. It could have been shorting out the motherboard.

So now I think it's either some components on the motherboard, like resistors and capacitors. Or it's the VGA card or NB or SB.

I'm going to do some tests with a DMM before I try the heat gun method.

 

An update:

I tried just plugging in the AC power to the motherboard.
I got the same results, the two lights come on.

This is with everything disconnected (CPU, HDD, ram, screen, everything).

It's just a motherboard sitting on my table connected to AC power.

The thing that bothers me is that as soon as I connect the AC adapter, the lights come on as if the is turning on.
I don't even have to press the "on" button.

This could mean a problem with the power components, right?
I checked the mosfets, they seem fine.

I checked the CMOS battery and it shows 2.73V. Seems fine to me.

I don't know what exactly is wrong. The CPU and NB get quite hot after a while.

I tried heating up the GPU slightly. No results.

I wonder what it could be?

I will be buying a heat gun soon to get the GPU really hot soon.

Just want to know what else I should try first?

 

I don't think it's the GPU, most Bios based logic boards should POST, without a GPU.

You're not getting to POST.( If it were POSTing, you could use a serial console to get around a BAD GPU, So I'd lay off the rework off the nVidia chip, until you get past POST.)

Sounds like a Dead CPU to me, could you give the Specs, and some pic's of all the parts?

 

Yes I will upload photos in a few mins.

Too bad you say it's not the GPU, because I just heated it up to 300C, and for a little while at 600C.

The CPU is a T8100.

 

ok, pics:

Base assy:


CPU (t8100 @2.1ghz):


Nvidia quadro NVS 130m and NB:


HSF:


MB:



Ram:


screen:


wifi:

 

Results of heating up the GPU were:
NOTHING

I think you're right about it being the CPU.

I have another notebook, a tecra A9. The two notebooks have the same chipset.

How do you test a CPU?
Should I try the bad CPU in the known good motherboard? Or should I try the known good CPU in the bad motherboard?

Could a bad CPU cause damage to my good motherboard?
And could a bad motherboard cause damage to my good CPU?

Thanks for all the help.

 

Test the "Suspect" CPU in the known good MB, I've never seen a BAD CPU damage a Logic Board.

While you have the CPU off the Suspect Logic Board, see if it's still powering up, when you plug it to AC.

Also, get as good of a close up shot/shots of where the main Power connects to the LoBo, and any DC/DC Power boards.

If it's not the CPU, you want to start probing to find what is tripping the "Power ON", as it should not auto "ON" when plug to AC.

Try and get some shots of the Power circuit as if it were a Diagram, maybe we can trace to the Power On trip.

Hopefully, if it's not the easy fix of the CPU, it's in the Power Circuit.

 

In general, there should be two leads in the cable that run from the "Power ON" Button, mounted on the Chassis. In a Two wire setup, one wire is Grounded, the other is open, when the Power On Button is pressed, the grounding trips the PSU ON.

Power flows to the LoBo's "Start UP IC" some Chip(Low level coprocessor) that loads a Firmware off one of the Smaller EPROM's. This Co=Processor sets up the "system state", before the Main Bios chip is read, and power flows to the Core IC's, CPU NB SB RAM GPU.

After the Main Bios is read, the system checks the NVRam for Users settings in the Bios, etc.

Corrupted NVRam can FIAL a POST, removing the Batt should reset this, but I've seen many Lobo's that it does not. Shorting the Batt connecter or Jumping it with 3v normally clears it Fault State.

It seems to me, that your system is failing to bring the Low Level Coprocessor On Line. The Bios is not read and boot fails.

Check the Power Button, make sure its Open, when it's NOT being Pressed.

Check the Logic Board connector and see if the "Trip Pin" is Grounded. It should not be unless the Power Button IS pressed.( I assume you'll find a fault here, won't tell us what is wrong, but it's a good place to start)

 

If you seriously ran out of ideas do the old fashion way replace each component then test.
IMO I have seen a lot of weird things happen therefore it is not easy to isolate issues due to the increase in complexity.
There was once I had a no boot because the RAM wasn't properly slotted in made me panicked a while.
Anyway first thing I would have done is hard reset press hold power button for 60 secs without any power but I am not sure if this will help.
I had a harddisk failure and it kept showing no boot until I did the hard reset with the harddisk remove then the no operating system prompt appeared and I was sure it was ok.
I don't think the motherboard will get damaged during a fall if the casing is intact.
The most likely damaged equipment should be a mechanical device harddisk.

 

Thanks again for all the help.

I tried my good CPU in the bad motherboard.

This gave the notebook some more life (fan is on). Also it stopped turning on by itself (so it's not a power button problem).


Now here is the strange part:
I put the good CPU in my good notebook, and it behaved just like the bad notebook (no life except fan on + lights on).

Then I held the power button for 60 secs (without battery and power cord) as suggested. It worked after that

So now I know the bad notebook has a bad CPU and something else is wrong with it.

I need a cheap socket P CPU to test with (I don't want to use my good CPU anymore for tests).

Can anyone tell me the worst (cheapest) socket P CPU for the PM965 chipset (santa rosa)?

 

Get a T2370, they should be around 20 USD used. Most people usually upgrade this right away to a T7500 or T7800 so there should be plenty for sale and cheap. It's a decent CPU. You can have it for free if you're in US. You helped me out before.

 

Thanks, I'll probably get one of these:
http://cgi.ebay.com.au/Intel-Celero...aptopMotherboards_CPUs_CA?hash=item2ea69b024f


If I can't fix it after I get the new CPU in there, I guess I will have to find a new motherboard on ebay (or another cheap notebook for parts).

 

More info.

I hold tab while I turn it on:
endless beeps, on light flashing, fan turns on.

I think this is some sort of diag thing, indicating a bad CPU in my case.

Unless someone knows toshiba beep codes?

 

Ok, so I downloaded the latest BIOS.

Then I unpacked the exe file with 7zip.

I copied the important bios files onto a floppy disk.
I connected an external floppy drive to the notebook, put my special floppy in.
Turn on the notebook while holding the ~ key.

There is activity, sounds like the floppy is being read, no beeps but green light flashes for 30 secs, then the notebook restarts.
According to the tecra A7 service manual, I just updated my BIOS.

Notebook still doesn't work.

Currently I'm looking for the diagnostic floppy image, please if anyone has a simmilar floppy give me an image of it