old school enhance 300w bad rubycons

[kc8adu]

yes you heard right!and a series i dont recall seeing.
+5stby low and would not start.both rubys were about 40 ohms esr!
the jamicons on the output were done too but not blown/leaking.
unit came with a cheap case in 2002.now its back in its case and in use in a mamebox.the owner wanted to keep the system all original as it was his first real computer that he paid for as a teen.the board is coming for a preemptive strike when he goes on vacation.

[c_hegge]

Re: old school enhance 300w bad rubycons

Interesting. I wonder what killed them. I take it those were NOS Chemi-con KZEs you used on the outputs.

[Wester547]

Re: old school enhance 300w bad rubycons

That MH looks like it's 7mm tall. To my knowledge, 7mm tall capacitors don't have anywhere near good enough ripple or ESR ratings for SMPS use except for the lightest of tasks (decoupling, coupling, bypassing, timing, etc)... not surprised it failed on +5VSB. Not surprised the Jamicons on the output failed either. The Jamicons usually seen in PSUs are general purpose. KZE was a good choice.

[ben7]

Re: old school enhance 300w bad rubycons

Looks like a strange one, could that be a real rubycon, or a fake?!
I don't recall rubycon putting the series code by the date and temp markings!

[kc8adu]

Re: old school enhance 300w bad rubycons

nos kze on +3.3 +5
fm on +12
1200@16 zl on +5stby.
doubt it will fail again unless it gets hit by lightning.

[momaka]

Re: old school enhance 300w bad rubycons

Did anyone seem to have recapped this PSU before? First thing that popped up when I searched for Rubycon MH was an eBay link to fake Rubycon MH caps. Perhaps the PSU had Jamicon originally, and then someone recapped it with these fake craps?
Then again, the bung of the cap in the picture you attached doesn't look like the cheap stuff on fake caps.

[MaXwELL]

Re: old school enhance 300w bad rubycons

capacitor is not original