How would treat your PSU if you experience this behavior? Not turning on at all when a bad cable is connected?

S

sram

[H]ard|Gawd
Joined
Jul 30, 2007
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Hi to all,

This has to do with a re-build I just did and I want to know if my PSU is still good or if what is a sign of failure. This is the PSU:
https://www.thermaltake.com/smart-pro-rgb-750w-bronze.html

The full story is in this thread:
https://hardforum.com/threads/which...t-for-an-old-asus-maximus-iv-extreme.2030030/

But I'll summarize it here. I wanted to move one of my systems into another case and I did but used a different motherboard. It turned on at the beginning but when I decided to plug in the SSD drives there was no sign of life whatsoever. I bought another power supply thinking the old might have died, but the new one (corsair HX1000) also didn't work. I bought a PSU tester and found that the old one actually works and the new one didn't so I thought it was DOA. I tried again with the old PSU and the pc worked but I had trouble detecting all SSD drives. Anyways, during one of the many experiments the pc didn't want to turn on at all when I added the last drive using a sata data cable and sata power cable. I disconnected the data sata cable but still no go. I disconnected sata power cable but still no go. While everything is unplugged (data and power cables) I turned the PSU off and back on then tried to turn on the pc and it worked. I kept experimenting many times and this is when I discovered that the sata power cable is the culprit. When I connect it to the PSU and disk the pc won't turn on. I tried another cable and everything worked. So it really was the power cable. Could a bad power sata cable cause this when connected to a PSU? Or should I suspect the PSU as well?

I went to return the newly bought corsair HX1000 and they tested it in the computer shop and it worked. I now know what happened. I must have used the bad cable at the very beginning when the pc didn't want to turn on, and I also must have used it with the new PSU when testing with PSU tester (I need to verify this but the problem is that I threw the cable away).

The system is working well now anyways, and it passes stress testing. But I'm little worried because faulty power supplies can do stupid funny problems.
 
Yes, a faulty cable can cause this. If it shorts one of the power rails to ground, it should trigger the overcurrent protection and cut off power. I think most supplies will not turn back on until they are switched off manually or unplugged for a few seconds.

As far as what to do: You could ask the manufacturer if they will RMA the supply or replace the defective cable under warranty, although neither is likely if you used 3rd party cables. The supply is probably okay, but I don't know how much damage could be done to the OCP circuit after tripping a few times.
 
Nobu said:
I think most supplies will not turn back on until they are switched off manually or unplugged for a few seconds.
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This is what happened exactly. The damn cable. It wasted my time. You mentioned tripping.....do you mean it turned on and immediately back off? I think the bad cable didn't allow the PSU to turn on at all. The fan didn't spin. I think if it trips the fan will move a little. Hopefully no damage is done.

Thanks for your input.
 
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sram said:
This is what happened exactly. The damn cable. It wasted my time. You mentioned tripping.....do you mean it turned on and immediately back off? I think the bad cable didn't allow the PSU to turn on at all. The fan didn't spin. I think if it trips the fan will move a little. Hopefully no damage is done.

Thanks for your input.
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I mean it trips an internal safety mechanism (probably some kind of resettable fuse). Usually they don't reset until power is removed from the supply, either by unplugging or by flipping the power switch on the supply (if it has one). While the fuse is tripped, the system will not power on at all -- it would seem as if the PSU is dead.
 
Biggest issue with fully modular supplies early on was they used physically compatible cables that were wired different. Pick one up for the wrong supply especially for CPU power and you were not having a good day!

I have a ton of old, high power stuff but not with a lot of hours. Exception would be the AX1200s from 2011 or so. Those are still going strong today!
I even have a 1600W Ultra X3 which is a BEAST. 77% efficiency at full load is a major ouch though.
 
Yeah, the OCP is faster than your eyes can perceive. As others have stated, always use provided cables or ones that have been vetted for the power supply. The PSU is probably fine now.
 
Thanks guys. I honestly didn't know you have to use the same cables that came with your power supply. One would mix and match cables. Shouldn't they be just standardized ? I'm surprised they are not. If for some reason you lose your power supply cables, where would buy replacements? Same manufacturer?
 
sram said:
Thanks guys. I honestly didn't know you have to use the same cables that came with your power supply. One would mix and match cables. Shouldn't they be just standardized ? I'm surprised they are not. If for some reason you lose your power supply cables, where would buy replacements? Same manufacturer?
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its been that way since you joined the forum.... lol standardized interchangeable cables, no one is going to do that. yes from the same oem, unless said oem points you to their oem...
 
sram said:
I honestly didn't know you have to use the same cables that came with your power supply.
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I'm surprised you didn't know this. Things have been this way for a very long time.

sram said:
Shouldn't they be just standardized ? I'm surprised they are not.
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People have been complaining about the lack of standardization for this for a long time. Would be nice if it happened, but it's never going to happen.

sram said:
If for some reason you lose your power supply cables, where would buy replacements? Same manufacturer?
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Yes. For example, if you need replacement Seasonic cables, their customer service points you to this site: https://btosinte.com/ols/categories/seasonic-modular-cable (Info from: https://hardforum.com/threads/where-to-buy-seasonic-psu-cables.2031863/)
 
DrezKill said:
I'm surprised you didn't know this. Things have been this way for a very long time.


People have been complaining about the lack of standardization for this for a long time. Would be nice if it happened, but it's never going to happen.


Yes. For example, if you need replacement Seasonic cables, their customer service points you to this site: https://btosinte.com/ols/categories/seasonic-modular-cable (Info from: https://hardforum.com/threads/where-to-buy-seasonic-psu-cables.2031863/)
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I'm being frank. I didn't know. I mean you buy your computer parts each from a different place and they all work together because of standardization. Plus one end of the PSU cables should be the same in all PSU cables because it will interface with the mobo and video cards...etc. To have it wired differently on the other end in each PSU is beyond me. If it is different, don't make it fit at least. You learn a thing everyday. Thanks to all.
 
djstarfox said:
Yeah, the OCP is faster than your eyes can perceive. As others have stated, always use provided cables or ones that have been vetted for the power supply. The PSU is probably fine now.
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It is fast, yes. If turned on to direct short to ground it will shut down quickly not damaging itself.
However if there is a different type of fault say 12V going where 5V should be, do expect damage to occur. The supply is likely to be fine but the connected device not so much.
 
cpufrost said:
It is fast, yes. If turned on to direct short to ground it will shut down quickly not damaging itself.
However if there is a different type of fault say 12V going where 5V should be, do expect damage to occur. The supply is likely to be fine but the connected device not so much.
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And the connected device can be the motherboard or video card or disks.....Everything is working fine with me now but it could be that one device or more are little faulty and causing funny illogical problems. Some devices when they go bad, they don't die but they cause you problems you would have never thought with your wildest imagination.
 
cpufrost said:
I even have a 1600W Ultra X3 which is a BEAST. 77% efficiency at full load is a major ouch though.
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not really, besides when will you ever be pulling 1600w? plus that's one of the main reasons to buy oversized power supplies, so you don't have to run them at full blast which makes them run hot and shortens the life.
 
d3athf1sh said:
not really, besides when will you ever be pulling 1600w? plus that's one of the main reasons to buy oversized power supplies, so you don't have to run them at full blast which makes them run hot and shortens the life.
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Renderboxes with multiple sockets loaded with GPUs.
The superflower titanium 1600W handily beats it in acoustics, stability and, of course, efficiency.

My SR2 system wasn't stable on it either, two AX1200s worked but the 3.3V was low enough to trip the Areca's alarm so we eventually went with a pair of Antec HCP 1200s that worked flawlessly. Delta was the OEM on those and they ran very quiet and held up well.
 
sram said:
I'm being frank. I didn't know. I mean you buy your computer parts each from a different place and they all work together because of standardization. Plus one end of the PSU cables should be the same in all PSU cables because it will interface with the mobo and video cards...etc. To have it wired differently on the other end in each PSU is beyond me. If it is different, don't make it fit at least. You learn a thing everyday. Thanks to all.
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It's because no one developed or agreed on a standard when modular PSUs were first introduced. Everyone just kinda did their own thing using off the shelf parts, the most common of which were the Molex plugs. It wasn't uncommon for within the same company to have different cable pinouts due to different OEMs, for example, I believe the original Corsair HX cables were not compatible with their AX series. It even happened in the same line; the AX750/850 cables weren't compatible with the AX1200 simply because they had different OEMs if I recall correctly.
 
Tsumi said:
It's because no one developed or agreed on a standard when modular PSUs were first introduced. Everyone just kinda did their own thing using off the shelf parts, the most common of which were the Molex plugs. It wasn't uncommon for within the same company to have different cable pinouts due to different OEMs, for example, I believe the original Corsair HX cables were not compatible with their AX series. It even happened in the same line; the AX750/850 cables weren't compatible with the AX1200 simply because they had different OEMs if I recall correctly.
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Yeah. I see that now. Honestly, if some friend told me this or wanted to correct me I will laugh at him. And now you are telling me it happened in the same line.
 
sram said:
Yeah. I see that now. Honestly, if some friend told me this or wanted to correct me I will laugh at him. And now you are telling me it happened in the same line.
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Yep. The early days of modular PSUs were quite literally the wild west. Better now, but still pretty bad as you found out the hard way.
 
Tsumi said:
Yep. The early days of modular PSUs were quite literally the wild west. Better now, but still pretty bad as you found out the hard way.
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Remember the supply that used these?

71LRNtmSQaL.jpg
 
IIRC it was OCZ.
And the cables were braided with metal and had a plastic outer covering. Stiff AF too!
Those connectors were common with communications equipment, chiefly microphones and were not really designed to carry much current but I suppose they could as I never remember them having issues. Of course the supplies weren't typically that big either.
 
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