Question dell latitude i7-Intel(R) Core (TM) i7-8650U CPU @ 1.90GHz

[mohan-hardware]

My pc detail: dell latitude laptop i7-Intel(R) Core (TM) i7-8650U CPU @ 1.90GHz, 16 GB RAM, 512 GB SSD

Every weekend I test my pc with Diagnostics & Tools & get the results for the hardware issues as below Image 4 months

https://imgur.com/VWq3kAj

View: https://imgur.com/VWq3kAj

https://imgur.com/Q93Dg6A

View: https://imgur.com/Q93Dg6A
After 4 months one day it continually restarts and work for couple of hrs. the next day when I ON no display, keyboard lights on and then turn off power button only ON, then I hard reset to shutdown.
I take to the service center they took almost 16 days & finally told need to replace your motherboard
[ Half or more of the price is Motherboard & It is not available in my country (Sri Lanka) but available in online very few of them, I show on eBay]
I wanted to know that do I have to change the motherboard, or it is possible to repair the motherboard

Laptop internal view

https://imgur.com/ug780ED

View: https://imgur.com/ug780ED
Can anyone mark in the picture where is the problem (Hardware which part need to replace)

 

[stonecarver]

If the display is not functioning how or where did the Test results get done.

My guess first thing I would check is the motherboards battery " coin size" in the black plastic that is to the left of the system battery where the battery says "Dell".

I would after that IF the battery " coin size " needs replacing get that done than go into bios and set to defaults.

The GPU failure is weird as that's part of your CPU that leads me to check the coin size battery 3.V when new.

It could be a driver issue but I would see where you get with a new battery.

The Adata hard drive might or might be a real issue, again after a new coin size battery is installed and bios is set to correct settings will only tell.

I would also remove the Adata M.2 Hard drive and reinstall to clean off contacts at the very least.

Question does it even semi function after it came back from repair shop. ?

 

[mohan-hardware]

If the display is not functioning how or where did the Test results get done.

I have done all the tests when my display works.

 

[Misgar]

This iFixit guide shows you how to replace your BIOS battery. They last for 5 to 6 years then slowly go flat.

https://www.ifixit.com/Guide/Dell+Latitude+7490+CMOS+Battery+Replacement/162254

Initial symtoms of a low battery include your computer "forgetting" the current data and time. Final symptoms, include failure to boot.

Other things to check include the ribbon cable up to the display and the backlight pcb (in the lid).

I wanted to know that do I have to change the motherboard, or it is possible to repair the motherboard

Doubtful, unless you have the service manual and the appropriate technical knowledge plus spare parts. Even then, it may be easier/cheaper to replace the whole board.

A few more things to check. Observing anti-static (ESD) handling precautions, unplug the DIMM (memory module) and check for dirt on the gold contacts. Avoid touching the contacts or memory chips if possible.

The only other user replaceable components are the WiFi module, the battery and the M.2 SSD.

You could check the four small screws securing the black heatsink/heatpipe to the CPU (above the SODIMM in your picture). If they're loose, the CPU will overheat.

You could try to get a working motherboard on eBay, but a complete second hand laptop might be roughly the same price.