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Electronics => Repair => Topic started by: jayjr1105 on July 03, 2020, 11:35:26 pm

Title: Question about these two caps
Post by: jayjr1105 on July 03, 2020, 11:35:26 pm

I have a PSone that needs these two caps replaced to fix video issues.  It's very common on this board.  I ordered replacement SMD aluminum caps 220uf 6.3v and I already removed the old ones.  They are reading normal around 220uf but ESR is well over 3 ohms.  Is this why they are bad? Original's are 220uf 4v btw.

(https://i.imgur.com/7EtqNRG.png)

Title: Re: Question about these two caps
Post by: helius on July 04, 2020, 12:08:37 am

At what test frequency was the ESR measured 3 ohms?
I'm not familiar with that circuit, but as a guess, I'd say that they are coupling the output signal. High ESR in a coupling capacitor can lead to weak signal drive. Other problems could be (electrical) leakage, which would cause DC offset on the signal.

Title: Re: Question about these two caps
Post by: Bud on July 04, 2020, 02:16:55 am

These SMD low profile electrolytic caps have high ESR in my experience, i mean higher than typical radial caps of same value, so 3 Ohm may be normal.