[SOLVED] Used the modular cables from a Corsair PSU on a Thermaltake PSU; now I can't reach POST

Oct 27, 2020
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I'm going to try and make this long story as short as possible. Initial problem was that my PC froze and I could not restart, either from the keyboard or the power switch on the case.

I powered down the PC by flipping the I/O switch on the back of the PSU. However when I flipped the PSU back on, all I got was the MB lights turning on and the fans spinning for a second or two before powering back down and then repeating.

Hoping it was the PSU and not the MB, I got a new Thermaltake Toughpower GF1 650W PSU. But like an idiot I used the same modular cables from my Corsair RM650x PSU. When I flipped the I/O switch on the new PSU nothing happened.

Realizing that using the old modular cables was a mistake, I next connected the Thermaltake PSU with the correct cables. But when I then flipped the I/O switch on the new PSU, the computer turned on without having to even press the power switch on the case! And it didn't really turn on; only the MB "Phase LED" lights, CPU fan, and fan at the back of the case turned on. There was no beep, no POST, nothing. I am getting the same result even with the power switch cable unplugged from the header on the MB! So all of this happens just by flipping the I/O switch on the PSU.

I have since cleared the CMOS by shorting the pins and have also replaced the CMOS battery. I have also removed all of the components except for the CPU, CPU fan, and a single stick of RAM. The Power/Reset/Speaker/HD LED's also remain plugged in to the MB header. The only cables from the PSU currently connected are the CPU and 24pin MB cables. Now when I flip the I/O switch to the on position, the CPU fan turns on and the MB "Phase LED" lights turn on, but no beep on POST. Again all of this without having to press the case power button.

What are the next steps that I can take to find out what components I have fired and which are salvageable? Luckily I am able to mount my HD's via a USB enclosure, so my data is safe. The CD rom drive was also operational when the computer turned on, or at least the open/close tray button worked, so I'm guessing that the Sata modular cable was interchangeable. Finally the fan at the back of the case did turn on, and that fan was attached to the Molex modular cable, so it looks like that cable was interchangeable as well.

My system is as follows:

MB - GA-P55M-UD2
CPU - Core i7-860
RAM - 2 x 8GB DDR3 - 1600
GPU - Sapphire PULSE Radeon RX 570 4GB GDDR5
PSU - Thermaltake Toughpower GF1 650W (was a Corsair RM650x)

I realize that this is an old system, but I have been successfully able to dual boot into Windows and macOS for over 10 years and I would prefer to salvage whatever I can of the MB/CPU/RAM. Any information would be greatly appreciated.

Thanks,

Bruno
 
Solution
"got a new Thermaltake Toughpower GF1 650W PSU "
"I used the same modular cables from my Corsair RM650x PSU "

You released the magic smoke.
I would suspect the motherboard.
Oct 27, 2020
3
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"got a new Thermaltake Toughpower GF1 650W PSU "
"I used the same modular cables from my Corsair RM650x PSU "

You released the magic smoke.
I would suspect the motherboard.

Thanks for the reply. Short of putting the CPU in a working MB, is there any way I can find out if the CPU was also fired? Also how can I test if the RAM/GPU still works? Trying to see if there is anything from this computer that I can salvage.

Also, is it possible that I also shorted Thermaltake Toughpower GF1 650W by using the wrong modular cables?

I've tested the Thermaltake Toughpower GF1 650W on a Dr. Power II and all of those connections seem to be ok. But when I first tested my Corsair RM650x PSU on the Dr. Power II, the Sata and Molex connectors flashed "red" or not working, but when I tried it again today, the Dr. Power II now says that all of the Corsair connections are ok! Some Dr... One of the reasons I replaced the PSU was because of those results.

But the spinning CPU fan and Phase LED lights only turn on with the Corsair RM650x PSU plugged in; when I plug in the Thermaltake Toughpower GF1 650W, only the Phase LED lights turn on; the CPU fan does not. In both cases the only connections to the MB from the PSU are the CPU and 24 pin MB cables. So did I short the new PSU? Is my original PSU ok? Can I trust anything if the MOBO is compromised?

Thanks again for the quick reply,

Bruno
 
based on what you said in OP i would assume (to be safe) that all (CPU, MB and PSU) parts are compromised including the but hopefully not the GPU. you will want to isolate each of the parts and test in a working system which may not even be worth it for you.
 

USAFRet

Titan
Moderator
Thanks for the reply. Short of putting the CPU in a working MB, is there any way I can find out if the CPU was also fired? Also how can I test if the RAM/GPU still works? Trying to see if there is anything from this computer that I can salvage.

Also, is it possible that I also shorted Thermaltake Toughpower GF1 650W by using the wrong modular cables?

I've tested the Thermaltake Toughpower GF1 650W on a Dr. Power II and all of those connections seem to be ok. But when I first tested my Corsair RM650x PSU on the Dr. Power II, the Sata and Molex connectors flashed "red" or not working, but when I tried it again today, the Dr. Power II now says that all of the Corsair connections are ok! Some Dr... One of the reasons I replaced the PSU was because of those results.

But the spinning CPU fan and Phase LED lights only turn on with the Corsair RM650x PSU plugged in; when I plug in the Thermaltake Toughpower GF1 650W, only the Phase LED lights turn on; the CPU fan does not. In both cases the only connections to the MB from the PSU are the CPU and 24 pin MB cables. So did I short the new PSU? Is my original PSU ok? Can I trust anything if the MOBO is compromised?

Thanks again for the quick reply,

Bruno
Until verified working in another system, all parts are suspect from an episode like this.

Spinning CPU fan means little.
 
Oct 27, 2020
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Copy, thank you all for the replies. Definitely a lesson learned. At the very least my data is safe, which is the most important thing to me, the rest can all be replaced.