Wonderful! Thank you for this. I have three of these chargers. One day, I’m going to need this.
Rick Wannall KG5ITH From: BVARC <[email protected]> On Behalf Of John Mechura via BVARC Sent: Friday, December 4, 2020 17:55 To: BRAZOS VALLEY AMATEUR RADIO CLUB <[email protected]> Cc: John Mechura <[email protected]> Subject: [BVARC] Baofeng Charger Greetings, I had noticed that my UV5R was taking too long to charge up the battery. The red light was still on at the base of the charger after charging all night (turns green when charged) and the little battery symbol on the display was showing empty. The wall wart was putting out 10 Volts dc so that was OK. The spring terminals that contact the battery in the base only had 5 Volts so it was determined that the problem was in the charging stand. (5 Volts will not charge an 8 Volt battery regardless of wishful thinking and hoping. --Duh!) Was it possible to dis-assemble the charging base? Yes! It required the application of a #1 Phillips screwdriver to remove all four screws and separate the bottom cover. And what did I observe then? Horrors!! Surface Mount Device (SMD) components, part of the reason that I retired from the repair industry. They are hard to see when your eyes get older. But it is still possible to solder regular discrete components in their place if room permits and there was plenty of room, so my hope endured. Noticing that there appeared to be some through-hole components I removed the circuit board and looked at the other side. There were only three parts on that side, a diode, an LED and an electrolytic capacitor. Looking more closely I noticed that one leg of the diode was slightly greenish in color. Upon touching the diode the leg crumbled from corrosion. Progress! Why would there be corrosion to the extent of crumbling the leg of a component? It came from the electrolytic capacitor close by! And indeed the capacitor was also corroding. To sum up this anecdote, after replacing the diode with a diode rectifier from a junked out VCR power supply that also furnished a replacement capacitor the base was re-assembled and full functionality was restored. The capacitor was a 10 microfarad at 25 Volts. The diode was a 4001 so any regular diode would do. The circuit board was well marked with polarity and identification on both sides. Oh, by the way, of the three spring terminals that contact the battery the center one is electrically unused. The charger will measure 8.02 Volts dc when plugged in when measured at these terminals. Sorry for being so long-winded, but I wanted to furnish enough detail that follow-up questions could be minimized. 73, Forgetful John, KI5HOC
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