TR4/4A Stock Triumph Radio Troubleshooting?

[karls59tr]

Anyone on here knowledgeable about the transistor radios these cars came with? I hooked up the battery,antenna and hooked up the speaker. The radio turns on and lights up the dial and if I take one speaker wire off and touch it to it's connector I get a snapping sound from the speaker but sound no volume. I'm not that electrically inclined but was hoping for an easy fix. This radio looks like the stock Triumph ones I've seen in pictures but does not have the "Triumph" lettering on the dial! Anyone know of a link to a schematic for the stock radio?
I could put a modern radio in but I just want to fix the old one for occasional use.

 

[TR3driver]

If you can give the model number, I probably have the schematic and troubleshooting information. (There were several different models used, with different internals obviously.) Here is what I have already posted (but there is a lot more on the shelf)
https://s258.photobucket.com/user/TR3driver/library/Radios

However, if it is not working now, I'd say the chances of an easy fix are slim. Electrolytic capacitors have a limited lifetime, and it's especially hard on them to leave them unused (discharged) for long periods of time and then suddenly apply full voltage to them. It's certainly possible to replace them, but there are some (moderately) special skills and tools involved. Then after you find and replace the defective components, you'll probably need to do the alignment as well.

 

[karls59tr]

Thanks for the info Randall. I'll probably take it to a specialist to locate the problem.

 

[TR3TR6]

A number of those radios back then were switchable from negative to positive ground, depending on the car. If the switch was not in the correct position when fired up, it usually knocked out one or more of the transistors. Just another issue to deal with.

 

[karls59tr]

A number of those radios back then were switchable from negative to positive ground, depending on the car. If the switch was not in the correct position when fired up, it usually knocked out one or more of the transistors. Just another issue to deal with.

Thanks for the info.