About six months ago, I asked for some help getting this radio set up:
(
Original thread at this link)
Thanks to the help, I was able to noodle out the pinout, and it's been my workbench radio, and working great. I replaced the burned out dial light with some white LEDs, I added a lithium memory backup battery, with blocking diodes to prevent it from taking a charge when the radio is powered up, and everything worked great!
That is, until tonight, when, like an
idiot I had a "hold muh beer" moment... I read on some website that with some radios, if you hold down the 1 and 6 buttons while turning on the radio, the display will show you the serial number.
Well, gee, that'd be interesting, sez me. So, I did it.
Did I
need to have the serial number displayed on the screen? Nope. I've already got it on the label! And I don't even need
that!
So, to make a long story short, I held 1 and 6, turned on the radio, and that was the end of my display... and my tuner... and
all of the buttons functionality with the exception of the tape reverse button.
The display is blank. Nothing at all displays -- and, the tuner is not working. The radio is stuck on the AM band, at no particular frequency, just sort of randomly meandering around. Every now and then it'll come up on a station, and then a few seconds later it'll meander off. Might come back, might not. (It's not doing a scan, it's just randomly meandering.)
Is there any hope for this thing, or have I destroyed it? Seems like a not-very-bright design if it can self-destruct the tuner if two buttons are pressed while it's turned on. Yeah, not very bright of me to do it -- but as a former programmer, I like to think that a simple "user-error" will
not be the end of the world for an application.
I know... it's an old radio. And it only cost me $2 at the Goodwill. But, dangit, I
liked it. It sounded great! I had some decent speakers hooked up, and a coax to an outside antenna, and I was able to listen to classic rock during the day on FM, talk radio at night on the AM, and every so often some decent folk/celtic/jazz on the PBS FM station.
The cassette player still works (other than the Dolby button now being dead, and the LCD not being functional), so I guess I can consider it a big ugly cassette player, but if there's some way to undo what I did -- if it's not really dead (just sleeping? <g>) -- then I'd like to be able to keep using it.
That's JUST what I was going to say! 
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.