does a faulty motherboard cause a screen to go blank?

hi all ive made an error and that was taking my laptop to a supposedly technician to see if he could fix the problem my motherboard was having. ive got my laptop back since he couldn't do a thing, but now when it boots it shows a blank screen only. so i thought it was a damaged gpu and reclaimed it to the technician. he bought it and tested the new gpu and the problem persist. he told me that it is the motherboard(maybe its true cuz it was damaged before) but he didnt showed me evidence of a new gpu or swapping it so i dont wanna buy a new mobo without knowing if its true. can someone tell me if this is a symptom of a damaged mobo?

 

This can be the case, if a vital part of the motherboard is damaged the laptop won't boot. When you turn the machine on, does the fan work at all, do any lights flash, or beeps come from the machine.

Have you tested a different CPU, RAM to rule these out, also try plugging an external monitor to see if anything show's up.

 

could be a number of reasons

 

Yes, could be the LCD or cable.

What is your laptop model?
The motherboard could be only 60$, or you could have some potential for upgrading the motherboard.

 

is an acer aspire 6920g. ive alredy tried connecting with to a monitor and no luck. everthing works but blank screen

 

It sounds like there is still a possibility that the graphics card is bad or incompatible.
Its hard to know unless you test it on another machine yourself and if its not identical to your old card.

CPU & RAM can also go bad. You should basically try it always with an external monitor, 1 ram stick at a time, 1 graphics card, swap everything and then try a new CPU.

I noticed your motherboard is somewhat rare unfortunately. There are a lot of similar models like the 5720g where the motherboard is about 60$, and you can even get a lesser socket-M board for about 40$.

 

ok. i decided to open the laptop and try to fix the problem.... and now it works fine. the lcd cable was improperly put. these technicians are bad and mediocre. i just need to find a new mobo since the laptop only works with battery. If someone here has one please let me know i shuould create a thread. i found one on ebay at 230.

 

That is good news though. Why does it only work on battery?
Maybe you could fix it. Especially if its the jack.

 

i already changed it and still the same problem..... even with battery i have to wait like 3 minutes for the laptop to work. first boot it just turn off again, second boot just shows black screen and have to wait like 3 minutes like for the mobo to heat up or something LOL. with the charger the laptop just turns on and off consecutively
----------------------
i want to update bios but i cant.... with battery its impossible

 

That definitely sounds like a faulty capacitor.

 

yes indeed. but technicians here on Puerto Rico are mediocre.... they only know just how to replace parts...... that i can do myself, theyre just stealing money.

 

Man, I have a similar problem, thread here. Which capacitor are you suggesting is faulty? My screen can be forced on using Fn+F6 then any key, but it generally goes off within seconds. Using an external monitor is the only way I can use this notebook