[SOLVED] What causes PSUs to pop

[bbjsjs]

So I had 2 PSUs in a span of a month to make it short,
1 exploded with sparks when i was ingame playing r6

the other made a LOUD pop everytime I switch on my power regulator

Was it a coincidence or not? the 1st and 2nd PSU only started to act when i decided to clean out PC and played around with the molexes from my fans daisy chaining it and such. I finally had the money to buy a much better PSU with an 80+ but I’m afraid of plugging my fans because it might repeat. reason for thinking it’s my fans is I saw thread claiming a bad molex can cause a short circuit

TLDR 2 power supplies popped and im suspecting it might be the molex connectors from my fans(?)

 

[sizzling]

Fans are unlikely to cause a problem, they don’t take enough current. Only if they were wired incorrectly would I expect an issue.

However 80+ is a rating of efficiency and not quality. There are some terrible 80+ psu’s available.

Please can you provide full pc spec and make and model of both PSU’s.

 

[bbjsjs]

Oh I see, but what could’ve caused the 2 to pop? They weren’t branded PSUs but the other lasted a few years not that it would matter tho

The build was
GTX 970 Strix
Ryzen 3 2200g
2x 8gb 2400 RAM
and the current PSU is Zalman ZM700-TX

 

[sizzling]

I can’t say what killed them but unbranded psu’s nearly always lie about their wattage and it’s not uncommon for them to die at under 1/2 their rated power when tested, sometimes with sparks and/or fire. It could be just a coincidence and the low quality.

Never cheap out on the psu, a poor quality psu can damage or reduce the life of other components.

 

[bbjsjs]

how would you identify if it’s a wiring problem tho?

 

[AllanGH]

If the connectors are properly seated, it's not a wiring problem, and "molex" connectors rarely "go bad". What usually happens is that people either overload a single PSU cable, or use adapter harnesses--which also overload the distribution cable--which will cause all sorts of not fun issues.

 

[bbjsjs]

hmm would that mean stacking them would be a bad idea? or just stay clear from badly made molexes?

 

[AllanGH]

Let's clear-up connector brands, real quick...

https://imgur.com/a/azIy4Kb

View: https://imgur.com/a/azIy4Kb

AMP on the left, and Molex on the right

https://imgur.com/a/dbeDWX4

View: https://imgur.com/a/dbeDWX4

Molex SATA

Now, what are you talking about?

 

[DSzymborski]

The solution would be to stop buying junk PSUs over and over again and simply buy one good one. The Zalman isn't good either. Wondering why junk PSUs pop is a bit like pondering why drunk drivers crash their cars.

 

[jonnyguru]

Let's clear-up connector brands, real quick...

https://imgur.com/a/azIy4Kb

View: https://imgur.com/a/azIy4Kb

AMP on the left, and Molex on the right

https://imgur.com/a/dbeDWX4

View: https://imgur.com/a/dbeDWX4

Molex SATA

Now, what are you talking about?

To be fair, Molex, AMP, etc. make ALL of these connectors. Nobody actually "owns" the design. On a side note: No manufacturer of PSUs actually USE Molex or AMP. They're too expensive.

They should just be called "peripheral" (for the 4-pin) and "SATA" (for the 15-pin).

 

[jonnyguru]

So I had 2 PSUs in a span of a month to make it short,
1 exploded with sparks when i was ingame playing r6

the other made a LOUD pop everytime I switch on my power regulator

The one that exploded in game was probably overloaded. A lot of cheap brands will slap "500W" on a PSU that is only 250W because there's no governing body to prevent them from committing fraud. It would take a class action law suit.

The second one blew up because you're switching it on and off through a surge strip, AVR, etc. whatever you mean by "power regulator". Pro tip: STOP DOING THAT.

ATX PSUs are meant to be always on with a live standby. If you unplug them, switch them off, etc., the bulk cap will eventually drain. When you re-apply power, that bulk cap has to charge back up again and it will do so with a large rush of current.

Now, a good PSU should have in-rush limiters, strong bulk caps that can handle a large rush of current, etc., but there's still a lot of variables at play.

For example: When you have a cap sit on a shelf for a long time, you have to "reform" it to get it to perform as it was design. To do this, you sloooooowly increase the charge to the cap over time. If the bulk caps were poorly stored or sat around a factory for a long time, they may not be able to hold a charge they did when they were new. And just because the cap gets installed into a PSU doesn't make it less susceptible to this type of failure. If the BUILT PSU is poorly stored or stored for a long time without a charge on the bulk cap, it can degrade and you end up with a PSU with a bulk cap that can pop at any moment.