2017-11-19 Royal 510 PCB hairline crack 

For FB group Vintage Transistor Radios 

Speaking of fuzzy garbled audio…  I won another auction for a Zenith “Royal 510” which I’d never heard of.  It turned out to be a Royal 250.  The seller got no bids at all, so with less than a minute left I bid the minimum ten dollars.

I got it this afternoon.  It needed the usual capacitors, but after I got done doing those, it was microphonic, any vibration from the speaker would set it off into a squawk or buzz.  I started poking around to find a loose solder joint, and I finally found one and fixed it.  But it still squawked.  I had to poke around and flex the PC board quite a bit before I narrowed down the point that was causing the problem.  It was a hairline crack in the PCB trace, least where one would expect, in the middle of a trace thickly covered with heavy coat of solder.  I bridged the crack with two heavy wires imbedded in the thick solder.  I don’t think it will break again.  I guess the PC board was flexing when it was being shipped, and finally the trace cracked.  The board itself looks okay.

I put it back together and Humpty Dumpty is working okay.  In the center of this photo is a ‘dogbone’ shaped piece of solder with the almost invisible hairline crack in the middle.

Leave a Reply

Your email address will not be published. Required fields are marked *

© RustyBolt.Info/wordpress