1. Check it with another monitor if you have one around
2. Reseat the ram
3. Reset the cmos by removing the jumper settings pin
4. Remove the Battery
If none of these fix it then check;
1. Power supply
2. Motherboard/cpu

Printable View
1. Check it with another monitor if you have one around
2. Reseat the ram
3. Reset the cmos by removing the jumper settings pin
4. Remove the Battery
If none of these fix it then check;
1. Power supply
2. Motherboard/cpu
I press the turn on button, nothing happen.
I unplug the power cord and wait for a minute, i plug back the power cord, computer turns on for 4-5 seconds and shut down.
I tested the RAM sticks, removed the video card, remove the battery, no chance.
About the processor, what happen if you have some thermal paste at the border?
Faulty power button? are you familiar with jumper settings? look up your motherboards jumper settings and substitute the reset switch with the power button jumper cable, meaning put the power button jumper cable to the reset switch button, hope you have a reset button if you do and you have a faulty power button the reset button will power your pc.
It's getting confusing lol
a faulty power button wouldn't turn the computer on for 4-5 seconds and then turn off lol
Sure it can, see #5 , https://www.lifewire.com/how-to-fix-...en-off-2624444
It can be, and it can be frustrating. Does your power supply happen to have extra conmectors that are loose in your case? Like they are connected to the psu on one end, and not conmected to anything else on the other? Make sure none of these are touching anything else including the case as they could be shorting your pc.
Do you have any more thermal paste? This seems to stem from when you cleaned your pc/ applied the thermal paste. If you have some paste lying around, I would try taking off the cpu, fan, and heat sync, and I would completely reset it onto the board. Clean off the few week old thermal paste, apply new thermal paste, make sure the heat sync and fan are unclogged from dirt, and make sure you set those both right before screwing in. Less thermal paste is generally better as it doesnt take too much.
The power cord thing does make it sound like a psu issue, but I would assume a diagnostics tesst would have them check the psu with a meter, and they did say it was a mobo issue not a psu issue. $450 is a lot as $200 would be more than enough for a decent psu and mobo that you could install yourself lol
You should be able to find a really low cost tech, maybe a student, simply post on your Facebook or find someone on Craigslist. They usually can come to you or you can drop off your computer, just tell them your max budget is like $50-75, they have all sorts of parts laying around if its not a motherboard issue. I can pretty much build a computer in minutes, and swaping out a mother board also takes minutes as does the psu so find someone who will do it for cheap.
I think I might found the culprit of the issue.
The power button cord (power LED cable) that is connected to the mobo. I manage to turn on my computer by unplugging it and plugging it back, then unplugging it. Computer doesn't shut down after a few seconds.
Bastards who diagnosed my computer removed the thermal paste on my cpu T_T
Hopefully it stays on now and does not give you any issues. I think skarj was trying to get you to start up your pc and psu without using the power button earlier to try to rule out the power button as the main issue, but his post may have been buried (or I misread it). It is pretty simple to do.
Diagnosising hardware issues is frustrating, but, if your pc continues to work properly, you may have just saved yourself hundreds of dollars by not giving it to a tech or just buying a whole new mobo or psu. Nice job!