Oscon Polymers - bad ESR?

[-HoNY-]

I unsolder 4 Oscon polymers 1200uF/4V SVP from Sapphire Radeon 9800XT. This card run 6 months with no problems but my friend short circuit by screwdriver - one memory smoke up (card work on 2D fine but in 3D have artefakts)

I test caps on RLC testing bridge (maybe corect translate?), but mine is too old (made in 1970) - available two testing frequency 1KHz and 100Hz.

measure:
1250uF / 43mR
it's correct on 1KHz or bad testing method or bad OS-con cap

[gg1978]

Re: Oscon Polymers - bad ESR?

Sounds about right, 43mOhm isn't that bad at 1Khz.. I believe most VRM's run in the 100 to 250kHz range right now, and Oscon's are much lower at that frequency range..

[-HoNY-]

Re: Oscon Polymers - bad ESR?

I believe most VRM's run in the 100 to 250kHz ....

Yes its true, PII mobo's are 150-200KHz and lastes MB are higher

range right now, and Oscon's are much lower at that frequency range..

It's standart feature on polymers? I meansure 20mR on elyts (used Nichikon 4,7mF HD)

[trodas]

Re: Oscon Polymers - bad ESR?

That is a good question. We need some samples of polymers to determine this, tough

[gg1978]

Re: Oscon Polymers - bad ESR?

Do you know what frequency your ESR meter uses when measuring ESR?? The one we have at work only does 60Hz and 1KHz.. I have to use an impedance analyzer if i want to measure at any other frequency.