ESR meter trap
On Thursday, February 1, 2018 at 3:00:29 AM UTC-5, Phil Allison wrote:
few here would disagree that using an ESR meter is the fastest and surest way to find bad electros.
Handy. Yes. Useful. Yes.
Just replaced a surface mount 33uf/25v on an LG sustain EBR31872801 board which had image persistence issues and rash. The board would show improve in operation with heat added to the board. Because of the amount of sm electros on the board, I used my ESR meter with tweezer probes as removal of surface mount electros for testing is not practical. C49 33uf/25v checked about a half ohm in circuit so I moved on. The rest of the sm electros on the board checked fine as well. After I found the problem with the scope, I tested the defective cap for ****s and giggles and it read good value but 300 ohms ESR out of circuit. Before installing the replacement cap, I took an ESR reading of the empty lands and it read half an ohm. The only other cap parallel to it is C43, a 1uf surface mount film cap with an ESR of ........ 0.5 ohms.