[SOLVED] chirping noise from PSU

[onlinename]

Hello,

I have an optiplex 9010 sff that died on me the other day. It suddenly froze and i pressed the power button for 5 seconds to shut it down. it powered down but it made this high pitched noise that lingered for around 10 seconds as it was shutting down, and a thumping noise coming from my speakers, and the power button displayed a blinking orange/amber light with no noticible pattern - not 3/2 or 4/2 or 7/1 etc that u see in the manual. just constantly blinking at a rapid rate.

I pressed the power button again and it didnt power up. It was late so i decided to look into it first thing in the morning.

By morning the amber light wasn't constantly blinking anymore but was a very quick single amber blink like every 30 seconds or so.

So i unplugged everything but the power and opened her up. When i did opene her i heard this constant, very low chirping noise from the system. Couldnt locate where the noise was coming from but knowing my issue was the power, i pressed the diagnostic button next to the plug on the PSU. THE CHIRPING NOISE STOPPED when i pushed the diagnostic button and the light turned green, and i could hear my fans turning on.

when i stopped pressing the diagnostic button, the chriping returned and the green light went away. pressed the power button , and still the system wouldnt turn on.

Then, I unplugged the motherboard from my psu, and the chirping noise stopped. i Had my HD's and other stuff connected to the PSU.

took out my gpu and memory and connected the motherboard to the PSU again, and the chirping noise came back. so im thinking it's not my memory or the gpu.

as far as i can tell the chirping noise only comes when the motherboard is connected to the PSU. cus the system wont turn on still.



so the question is , is it my motherboard that's gone bad or my PSU? or could it be something else?



thanks in advance.

 

[Karadjgne]

Dells use a couple different OEMs for the psu, Seasonic and Delta are about as good as it gets for those and they have decent protective circuitry for all that they are cheap. But Dell also uses Sirtec, FSP, SuperFlower and I believe HEC/Compucase which for those OEM psu's are on the bottom of the barrel. Some are so bad quality they shouldn't and usually don't, meet atx standards for anything. This is common practice in pre-built pc's, designed to be cheap, so the absolute cheapest gets the contract. Dell gets many of its psu's for about $8 a unit.

That said, I think you got one of the crappy psus, but it's the motherboard that's bunk and instead of good protective circuitry kicking in and preventing further issue, that crappy psu is still trying to start, no matter how bad the damage to the motherboard is.

I'd be looking for blown/leaking caps, possibly scorch marks from a short circuit, check both sides of the motherboard for discoloration or bubbling, check every wire for melted or burnt spots and 'weld' marks from a short to frame where wires might have been pinched etc.

Personally I'd toss both. If it's the psu, there's no telling the damage to the motherboard it's caused, and you won't know until a new psu is applied. If it's the motherboard, there's no telling if the psu caused the fault, and using the psu on a new motherboard won't repeat the damage and fry it too. Unless it's an obvious thing, like a short in a wire to the frame (most interiors from Dell have a ton of plastic) both are suspect and neither can be fixed or diagnosed to the damage extent without running the risk of further damage to new components.

It sucks, but better to be safe than waste money on maybe's that turn out bad.

 

[onlinename]

Thanks for the reply.

I got another PSU from ebay and swapped it.
seemed to have done the trick. no chirping noise. so i reconnected everything to the system and lastly the powercord. This time it did what it was supposed to do. the psu light on the back turned green for about 3 seconds made some noise ( thats' what dell's website says SHOULD happen with a good psu when you plug it in)

windows couldnt boot for some reason initially, but after windows diagnosed the HD under safe mode it seems to be ok now.

 

[Karadjgne]

Wow, you got lucky. That's great that it was contained to just the psu with a data error to the hdd.

Good job, good luck 👍