I should have added that you can get a pretty good idea of whick branch on a PCB is drawing current by probing along the trace. This is especially useful if the rail has a bunch of branch distribution lines.
Also, if the three-terminal regulator is overheating, disconnect it and power just that rail from an external, current limited supply of a volt or two. That way you don't risk trace damage. Best, -John ================ > My SRS SR-620 counter died last weekend. After superficial > troubleshooting, it looks like there's probably a short on one of the > power supply rails. Symptom is that nothing lights up when power is > turned on, but one or more of the three terminal regulators gets very, > very hot (can't tell which one since they're all bolted to the side rail > as heat sink). The unit had been running continuously for several weeks > when the failure occurred. > > I just learned from SRS that they charge a flat rate 25% of the current > list price for repairs! (To be fair, if you're the original purchaser, > it's only 20%.) The SR620 currently lists for about $5K, so we're > talking about a mighty expensive shorted cap (if that's what it is)! > > Anyway, has anyone here troubleshot an SR-620 with a problem like this, > or have any general insights about working on one of these beasts? > > Thanks, > > John > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
