[SOLVED] GPU Suddenly Not Working When 8 Pins Plugged In

Farid Djebara

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Jul 23, 2013
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So recently I've been using more rendering type software like Blender and Vegas Pro. Earlier today after rendering a video, both of my screens suddenly turned a dark brown colour, and then off after a few seconds.

When I tried to turn my computer back on it made the POST beep as usual but none of the monitors turned on. The PC would also not even go into the BIOS screen it would just be blank. I could tell it wasn't going past because it would immediately turn off after I pressed the power button again no matter how long i left it on (usually it would require me to hold it down to force turn off).

I opened the PC up and individually tried out each component, finally finding that the issue came from having the 2x8-pin connectors plugged into my GPU. The moment I take a single pin out the PC turns on again, the GPU fans are still running, but the GPU HDMI connections don't work, only Integrated Graphics do. The GPU also does not get picked up by device manager.

Problem
PC suddenly displays "No Signal" black screen only when all 2x8 PCI pins are connected to it. When unplugging any single one of these pins the PC starts up as usual but the GPU inputs do not work and it does not show up on Device Manager, but the fans and lights on it still turns on.

I have had this PC for almost 9 years now and haven't fiddled with the cables in the past 2 years so this is very random. Anyone got an idea of what the issue might be? Hoping it's a faulty power supply to avoid having to buy a new Graphics Card, so going to test out a new power supply this weekend.

Specs
Motherboard - Sabertooth Z87
CPU - Intel core i7-4770k
GPU - Sapphire Radeon HD 7970 Vapor-X 6GB
PCU - Smart SE 730w power supply
RAM - 4x4GB (16GB) DDR3
 
Solution
Mostly the quality of the components used.
Thermaltake is mostly avoided in power supplies because of cheap components. They have a couple good units. The smart series was not one of them.
The MWE V2 is a good unit While the MWE V1 is to be avoided.

Farid Djebara

Distinguished
Jul 23, 2013
14
1
18,515
The power supply is suspect no 1.
It was not a very good unit to begin with. Not garbage but not good.
But without known good parts to swap out it is a guess.
Any recommendations?? I’ve ordered this one since it can come today as a test, but if there’s any you think are better please share.

Cooler Master MWE 750 Gold V2 Fully Modular PSU (UK Plug) - 80 PLUS Gold 750W Power Supply Unit, Flat Black Cabling, 120mm HDB Fan, High-Temperature Threshold - 5 Year Warranty https://www.amazon.co.uk/dp/B08NHW9TJ8/ref=cm_sw_r_cp_api_glt_i_7ZB69DDE80EVQG7MH69B

Also what makes the unit not good?
 
Last edited:
Mostly the quality of the components used.
Thermaltake is mostly avoided in power supplies because of cheap components. They have a couple good units. The smart series was not one of them.
The MWE V2 is a good unit While the MWE V1 is to be avoided.
 
Solution