PSU Burning smell (Corsair GS700 80+ Bronze Certified)

Achint2000

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SYSTEM SPECS:

Corsair GS 700 +80 Bronze Certified
ASUS P8Z77-V Motherboard
intel core i5 2310 @2.9 GHz; OC @ 3.5 GHz (CPU)
G.Skill SNIPER 8GB (4x2) @1600 MHz (RAM)
ASUS Strix 970 4GB [BIOS MOD] @ 1455 MHz Core, 3.2 GHz Memory (GPU)
Deepcool GAMMAXX400 CPU Cooler + Arctic Silver 5 Thermal Compound (CPU Cooling)

P.S, I'm not a noob to these things, I'm definitely sure it's exactly the PSU which is giving the burning smell.
PSU's warranty ended just a few months ago back in 2016. (3yrs warranty).

I made my first build way back in starting 2013 and had Corsair GS 700 since the start for future proofing. I keep my system switched ON 24x7... Sometimes it's idle, sometimes downloading stuff, sometimes defragging my hard drive. But I hardly turn it off. It's an open-case build, never ever had any problem since past three years. I take care of the dust. Since all those years, I've changed almost every single part of my build except the PSU and CPU, both were great.

Now, yesterday, while studying, I was playing Need for Speed 2015 on maximum graphics. I have my screen resolution forced to higher than Native: (1366 x 768) (19") to (3600 x 2025) Maximum and I had it on to there with full graphics plus ReShade Graphics Mod on quite a heavy preset, for continuous two hours (99% GPU, +80% CPU) and still, everything was "perfectly fine". No overheating anywhere.

No matter what, my CPU temps go hardly above 70 C in the most extreme usage conditions, and GPU never goes above 65 C either.

On a regular basis, once a week, I run an intel CPU Burn test, Heaven and Valley Benchmarks, PhysX Mark and some other benchmarks to make sure everything's fine.

Now, today dad smells something heavily burning from my room while I was watching a TV show online. Just chrome running, CPU idle, GPU idle, everything almost idle, CPU around 35C, GPU 40C. After a short while of smelling around, it was coming directly from the PSU.

After a while I started it again after blowing some air into the PSU using an air blower, to clear the smell (and a bit of dust) and I was on the advanced BIOS screen. After like a minute, same smell started coming again, where there was NO LOAD on the system at all. I logged into Windows when dad suggested I just turn it off or things could go bad. It's fan usually doesn't spin until I'm gaming or it's idle for a long time. This time, after the restart, it's fan was continuously running, giving out even more burning smell but not that much heat.

It all still starts normally, just like usual, except this time, my mobo's CPU Error LED lit up before I powered the whole thing on and off, TWICE. It happened a few times before but never twice.

Comp's off since over six hours now and I'll diagnose it, by clean starting it without all external USB Devices and without my Strix 970 (using internal gpu) and if I get to the BIOS where I can see some voltage readings, I'll update if I catch something wrong on the voltage readings. Resetting BIOS to default would be another good step, would be a no-overclock start.

I'll also need some quick temp solution in about two days as my computer project submission is due and all I programmed is on that comp's internal HDD and I have no other way to access it yet.

Until then, any suggestions or solutions? (except I should get a new PSU...)
- Thanks.
 

engineer5261

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I would not use that PC until I get a new PSU (or send the current one for service) as I would not like to put my components at risk and it seems very obvious that your power supply is failing. I would use your hard drive in a different computer to recover your project files.
 

Achint2000

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What I don't get, is everything's still fine except the smell. I still have to try some basic solution tricks. My wallet won't like another $100 out so easily :\
 
Don't fool around with a suspect psu.
Replace it with a tier 1 or 2 unit from a list such as this:
http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html
Or,if you can, borrow a psu to test with.

Corsair GS probably has sufficient protective circuitry to keep from damaging other parts, but why take a chance?
It is not going to fix itself.

Are you certain the smell is from the psu?
If you have overclocked a monitor, I might also suspect that or even the graphics card.

If a psu replacement fixes everything, see if Corsair will RMA the unit anyway.
After all, it must have taken you quite a while to confirm the problem.
 

engineer5261

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I would not use that PC until I get a new PSU (or send the current one for service) as I would not like to put my components at risk and it seems very obvious that your power supply is failing. I would use your hard drive in a different computer to recover your project files.
 

Achint2000

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I'm from India and I don't think it's that easy to "borrow" a PSU here.

Yes, certain that the smell is coming exactly from the PSU. It didn't take that long as I just smelled it quite close, and as I smelled probably every single other electronic thing on my desk like a police dog, and after clearing the smell and restarting, it was the one giving burning smell.

I'm considering all simple possibilities here instead of spending money or spending time on waiting for it to get fixed or replaced, it might be a bad voltage fluctuation while my headphones were on, might be something gone into the PSU Box, might be just something I hope could just get fixed by itself xD

Back in 2013, as a noob and a kid, while fooling around my PSU box with a screwdriver marking scratches, I accidentally flipped the voltage switch on my Cooler Master 350W PSU from 220V to 110V and it went firecrackers, smoked room and bad smell. When I got it checked later, it passed all the tests and was perfectly fine. That was when I changed most parts on my build, including PSU, GPU, Mobo, HDD, CD/DVD RW, CPU Cooler.

I still have that PSU in store room but I don't know if it'll do good after 3-4 years of not-being-used and kept in the dark, or will it do just fine as a temp replacement? I'll remove my Strix 970, run it on iGPU instead, if the old psu can do.

The overclocked monitor must not be an issue because without forced high resolutions from GPU Driver, on the BIOS Screen, it's just the 640x480 BIOS Screen. And anyways Higher resolution = more VRAM and I have 4GB VRAM on my GPU.

So, considering my default diagnosing solutions list,
Start, reset BIOS, Remove GPU + other unnecessary things, run benchmarks if no smell. Just this one basics test tells the exact thing having or causing a problem in the build...

I'll give it a shot and, if things don't work, will the old PSU do fine without the GPU?
 

Achint2000

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Before I tried starting it again, I smelled it again and it doesn't smell like some simple problem. Smells like some cake toasted for hours till it became a rock (my younger brother did that, in an oven xD)

I took a small flashlight and peaked under it's fan and saw a brown coil, with a brown wrapper-like core underneath it, CRACKED, with silver metal under that. I'll post a picture:



where the original one from hardwaresecrets looks like:



Even after 7 hours of shutdown, in like 17 C temperature (its winters), the PSU still smells like burnt, while its turned off.
Now I won't even try to turn that thing on again... :x

Now it's 5:18 AM ... Wasted the entire night searching a solution.
Seems like it's some kinda burnt coil with a risky cracked core... Might be a "torroid coil" as what I found on google.
 

Achint2000

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After about 18 hours of power-off state, I removed every single thing from the machine except the CPU Fan, CPU, RAM and Power Supply. (yes, no HDDs/CD-ROMs/USB Devices/PCI-E Components)

Started it up, just at the BIOS and waited.
Checked every single voltage, it was all fine and normal.
Also restored the default BIOS physically from the BIOS Cap before starting.
So, from the software part, and every other hardware part, it was perfectly OK.
All default mobo checks passed instantly, just as if it's a normal boot without any problems.

After 5 minutes, again, that same burning smell started, even worse than before, and the PSU Fans started running to keep the heat out. Again, it wasn't that hot. I thought I could wait another minute but I heard a small pop (as if someone's knuckle cracked) and I didn't take any more chances.

I've removed the PSU, packed it back in it's box to try for a repair/replacement at the nearest service center tomorrow. Hoping it'll be repaired or replaced... :\
 

Have you checked to see if your three year old power supply is still under warranty?
 

Achint2000

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Yes, just finished checking. I bought it from a website in August 2013. Certainly it's warranty has expired. What now?
 

Achint2000

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Yes, i'm sure warranty is over. I'll still try give it to Corsair service station before I try anything else.

Update - I got that PSU repaired but from a local shop as it was just out of warranty. The PC worked fine for a few months and it suddenly killed the motherboard one night by mid april this year. No smell, nothing. The board just died.

I got a completely new build now. Thanks for all the help.
 

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