PSU or motherboard gone?



I have gaming PC.

i7 processor
AMD Radeon Vapor-X R9 290 4G GDDR5 (I believe) blacking out my PC constantly - (NO blackouts when card is removed to onboard graphics)
16 Gb RAM
128 SSD
3 TB HDD (replaced once already)

Maximus VII Ranger Motherboard (Asus)
PSU Corsair RM 750X (replaced once alredy)

Tower fans (3 replacements at least)


my PC just died. I was shutting down the pc as normal. It however, actually tripped the fuse box and that turned off the router, plug and monitor and probably other things. On turning the fuse back on, the router, Switch and even monitor came back on but the PC was dead, no lights anyway, no fans, no sounds, nothing.


I had this PC built in 2015, it failed from day 2 and a catalogue of problems. Many fans broke down and had to be replaced, the 3 TB broke as well and was replaced and as I recall the PSU failed about a year ago and had to be sent back to be replaced.

I have been getting black screens and this seems to be the video card, which the manufacturers gave me a bit of run around on this.

I emailed them and they have said the same thing for the first time and want me to send it back - the whole machine. When I did that a year ago, they took 3 weeks and didn't even look at the machine until I chased them up and I had to pay for the priviege of sending it to them and it was under warranty.

What have I tried to solve this issue?

Following this guide I tried most if not all this things:

1) Tested all the switches. Back, Start up button on the front

2) Checked the fuse in the power cable (as it did trip the fuse box) and THEN tested another cable.

3) checked the cable was seated correctly, lamp test.

4) Removed the Graphics card - have done this before when the black screens started over 2 years ago and as per instruction from the manufacturer where the internal graphics would kick in to ALSO see the CMOS battery and replace it. Still dead.

4b) And I tried the start buttons on the motherboard, still nothing. (Usually lights on the motherboard and graphics are lit up which can be seen through one clear side panel of the tower).

5) I then cleaned my PC. I try to do this regularly and though there was quite a lot of dust, most of it was
caught in the external filters and the PSU seemed to not have much at all.

I then got the reply from the makers (see above), but as I am confident I can replace the the PSU at least, I just need to know how likely is it to be the PSU or could it be the motherboard? They did not answer my question on the warranty and as I paid for it once and they didn't even bother looking at it till I chased them, if its something I can do, I would rather do or go local as it will be out of warranty.

Am I missing something or could I try something else?

I think the PSU has just overheated and if I did buy another and it was say the motherboard, I would still have a spare PSU as they did replace the last one.

I can't believe this newest PC has had more problems in less than 3 years, than all the many PCs and laptops I have had in the last 20 years combined!

Thanks for any advice and thanks for reading.


Okay, after contacting my PC makers who didn't answer my question, I went ahead and purchased a replacement power supply unit. A very good company and all packed up nicely and delivered fast. Installing it was easier than expected, just putting the same cables into the new power supple unit - connecting and cleaning everything and switching on. Of course I loosened a cable (as they were tightly packed) on the SSD, but once that was solved, back in business. Job done.

I will be getting a cheap air blower to clean out the dust (in my garden outside) to make cleaning this easier and save on buying loads of expensive compressed air cans in future. Dust is pain for desktops and I do not want to go watercooled.

Thanks for reading