Toshiba l850 screen goes crazy

[unimer]

Hello,

Few days ago I turned on my laptop, and when it booted it just freezed and there were lines of all colors across the whole screen. I restarted it but then screen didn't came up, it was black. Not even a backlight.

After two days I turned it on again, and it booted properly, screen was doing good, and then after about 10 minutes of work, screen became colored again with those lines.

Now it puts black and white noise on a screen shortly after displaying Toshiba logo while booting, and then it goes black.

Did anybody experienced similar problem?
What it could be, and from where I should start debugging?


Thanks in advance.

[mcplslg123]

Re: Toshiba l850 screen goes crazy

Does it have discrete graphics like nvidea or ati??

[piernov]

Re: Toshiba l850 screen goes crazy

Should have an AMD GPU, something like 216-0833000 and it does go bad pretty often so could be the issue.

[unimer]

Re: Toshiba l850 screen goes crazy

Exactly, it is AMD GPU, 216-0833000.

Since I'm not in business with hardware repair, but I'm interested to learn it and do it as a hobbyist, please, inform me what is the best option for me to fix this problem.
I saw those GPUs on ebay for very cheap.
How hard is it to replace this chip without BGA rework station?
Also, please recommend me some suppliers you trust, if you think that ebay might be a bad choice.

[mosfetratus]

Re: Toshiba l850 screen goes crazy

Exactly, it is AMD GPU, 216-0833000.

Since I'm not in business with hardware repair, but I'm interested to learn it and do it as a hobbyist, please, inform me what is the best option for me to fix this problem.
I saw those GPUs on ebay for very cheap.
How hard is it to replace this chip without BGA rework station?
Also, please recommend me some suppliers you trust, if you think that ebay might be a bad choice.

It would be cheaper to buy a new or used laptop, than trying to fix it.

+ you have to find working GPU chip.

+ You have to have proper training, it's not simple soldering.

There is no way to change it without rework station.

Just buy a new laptop. Sending it for repair is not cost effective, depends on laptop specs.

[bachir2004]

Re: Toshiba l850 screen goes crazy

before doing anything try another ram stick.

[unimer]

Re: Toshiba l850 screen goes crazy

I didn't touch anything. And it is working all day long with no crashes.
Strange...


Thank you guys for response.

[ktmmotocross]

Re: Toshiba l850 screen goes crazy

give it a hour furmark. if it is gpu it will sho up again

[unimer]

Re: Toshiba l850 screen goes crazy

Oh.. It fails after 30 seconds of furmark.
I found used motherboard for 15€ on local e-commerce. Guy claims that it's working. I will give it a try.
However, since I'm beginner I will use my old board to practice on it.

What is possibility that there is some power issue?Maybe there exists cap that is failing? Since it works for hours until stressed.

[ktmmotocross]

Re: Toshiba l850 screen goes crazy

no just reball, but if it fail again u must replace it

[mosfetratus]

Re: Toshiba l850 screen goes crazy

no just reball, but if it fail again u must replace it

reballing dead gpu? What difference does it make.

[piernov]

Re: Toshiba l850 screen goes crazy

GPU is dead. 216-0833000 is among the ones that are very unreliable. Bit more reliable than the HD6000 series but still fails way too often.

Also the GPU isn't cheap, what you find for cheap on eBay/Aliexpress is garbage, it's already dead. You can check see-ic on eBay when they'll be back, they're the only one that can somewhat be trusted (they sometimes sell garbage too though) to see what the price of a real new chip is.
Used motherboards often have a dead GPU that was heated to work a couple of days/weeks/months.

Even after replacing the GPU, it may fail again eventually (but should usually last at least 2 years) as they're just garbage.

Sometimes you can convert from dGPU to iGPU only. Dunno if it's possible here.

Reballing is bullshit.

[ktmmotocross]

Re: Toshiba l850 screen goes crazy

reballing dead gpu? What difference does it make.

u dont know if its under die or under substrate./even if 99% of time it is under die/
reballing and hour of benchmark gives u exact answer

if it is not worth it to replace u can give reflow and test if it last something, but i prefer reball, i did not make reflows

[piernov]

Re: Toshiba l850 screen goes crazy

Reballing is pure loss of time, not an answer to anything.
Most of the times the chip will react to heat and work again for a couple days/weeks/months, but it's not reliable at all.

[ktmmotocross]

Re: Toshiba l850 screen goes crazy

if months than it is worth

[mcplslg123]

Re: Toshiba l850 screen goes crazy

if months than it is worth

I too dont agree with you. Its total loss of time as far as gpu is concerned. for intel PCH, reballing does work for a longer time.

[unimer]

Re: Toshiba l850 screen goes crazy

We can conclude if the problem is with balls by pressing a chip maybe? If we get some good signal then it's worth reballing.
It's somehow logical to me, if there is a physical damage on balls.
But in my case, everything is working fine until stress.
In this case reballing would be actually reflow with extra feature (new balls).