Discrete graphics card not detected on laptop

Question

Do it yourself

One fine evening, while playing, the Acer 5755g laptop went out, when it was turned on, the power indicator lit up, the cooler started up, the hard disk indicator blinked a couple of times and the laptop turned off. And how many times I didn’t try to turn it on - the same thing (I checked it just in case), I tried it with and without a battery.
I gave it to the service center - the diagnosis - the video chip burned out, which is nVidia GeForce GT 540M. They soldered a new one, launched it - it works, they returned it to me. I brought it home, I look in the equipment manager, and it shows me only one video chip - Intel, and not a hint of the second (before that there were two). I look in the tray for the utility for managing the NVidia video card, and it answered me with an error - they say there is no such equipment and there is nothing to manage.
I decided to reinstall the drivers, started with the Intel chip, then NVidia, but during the installation of the second one, it swears that there is no equipment. I ran programs like Aida and other things - they see only Intel. On the advice of servicemen, I reinstalled the OS - the result is the same, I updated the BIOS - there is no sense. On the Intel chip, it heats up terribly, I launched an average toy for testing - the temperature of the chip rose to 90+. I took it to the service center for the second time - they decided that maybe the chip that was soldered, defective, soldered, soldered a new one - the result is the same. Now they took a couple of days to think, they said that if they don’t find out the reason, then they will return everything to its original state and give the laptop back. But that doesn't make it any easier for me. Hence a number of questions:

1. Has anyone experienced something similar?
2. Is the reason in the hardware or is it possible that there are troubles with the software?
3. How is it possible that the discrete card is not defined, but the laptop runs on the built-in Intel? Those. before that, Intel was also serviceable, but only NVidia burned out and the laptop did not start at all.
4. What is the probability that when replacing the video chip, any contact was damaged and because of it similar problems.

Of course, I did something stupid myself, apparently, I took it to an unofficial service center, relied on their experience (more than 10 years) and expected that there was nothing difficult to repair there. When I pick up the laptop, I'll contact the officials.

UPD: in general, the whole problem was in defective video chips, which were installed twice, the third time was lucky.
UPD2: the problem did not end there, literally a day later everything died, returning the laptop to its pre-repair state. Only one conclusion suggests itself - the last time they soldered my own chip, which worked for a day and died safely. I gave the laptop to the official SC, I'm waiting for a diagnosis.
UPD3: the northbridge was replaced - everything worked.

Answer 1

could it be a faulty northbridge?

Answer 2

Don't you have a switch in the BIOS that looks like "integrated graphics only" and "hybrid"?

Answer 3

Has the warranty expired? if not, then let them simply replace the vidyukha with a new one in the off-line service, it is also removable. Well, accordingly, if it is over, then let everything be returned in your non-official service (including money for repairs, as I understand it) and buy a new vidyukha.
PS: I realized that the video card is removable according to the bottom table here: note.utinet.ru/notebook/acer/aspire/5755g/
Look for a video card on a gf117 chip, because it is made on 28nm technology and heats up less than yours, which is 40 nm (after all, as it turned out, the cooling system failed)

Answer 4

In an unofficial SC, the video card in your laptop was hardly changed - most likely it was “warmed up”.
The likely cause of the malfunction (I encounter this very often) is overheating of the video card chip, as a result of which it is partially soldered from the motherboard, warming up helps but only until the next soldering, it is necessary to eliminate the root cause - overheating of the chip - clean the cooling system from dust, change (remove the excess) thermopath , change the thermocouple

Answer 5

Regarding the third question, yes, it is possible. Recently there was the same problem on a younger acer (like 3750) - reinstalling the BIOS from a USB flash drive saved me from a black screen.
Regarding the fourth question - Next to the chip, and throughout the motherboard, there are many different SMD components that are very easy to brush off when soldering with a hairdryer.

Answer 6

A BGA chip transplant is a lottery with an 80% chance of winning. There was a reason why the native video chip burned out. What else he took with him to the grave - one textolite knows. In addition, our Chinese chip sellers often sin by relabeling chips. In short, there are a lot of factors and most of them are not in favor of the owner of the laptop. The beech is not cheap and it is a pity to throw it away, but resuscitation can turn out to be financially overhead. Of course, you can show the patient in another service, but you will have to pay for diagnostics again, at least. Ask the masters how much it will cost to replace the entire motherboard with a new / serviceable one. This way is more reliable and will give an idea of ​​the advisability of buying a new one instead of repairing it. Good luck.