VINTAGE TRANSISTOR RADIO REPAIR PORTABLE

Occasionally it’s obvious where a wire belongs, other times not so much. Reconnecting these mystery wires can be easy or a nightmare. Always, always take pictures and make notes if you disconnect wires for any reason!

Sometimes we intentionally disconnect wires in the disassembly and repair process. They can be ripped off of the circuit board when we replace batteries, take the radio apart for cleaning or repair, and so forth. Battery, headphone jack and speaker wires are all common issues. Disconnected or Broken Wiresĭisconnected wires are often another trouble source. Radios that cover AM, FM and Shortwave bands typically have band switches used to select the frequency range & electronics necessary to receive the various signal types. Other times you will need to disassemble the switch (risky), or replace it with one from a parts donor. Sometimes these can be fixed with contact cleaner. For instance, I have seen perhaps a half-dozen Zenith Royal 500H sets with defective power switches. Less frequently, power or tone control switches fail as well. Unfortunately, some switches are often difficult to reach for cleaning, and are a nightmare to replace, even if you can find a useable donor part. If a radio doesn’t play it is very likely that one or more switches will need cleaning.Īgain, a squirt or a dribble of contact cleaner might be all that is needed if toggling the switch multiple times does not cure the issue. Switches collect corrosion and dirt over time, especially if a radio has spent lots of time near salt water. This will disable the earphone feature, but sound will play through the speaker. As a last resort, you can wire around the broken connection.

You might need to replace, rather than repair these. Occasionally, bending the contacts with needle nose pliers might be necessary, but it’s easy to do more harm than good. If this fails, resort to contact cleaner. Start by inserting and removing a plug repeatedly. Use the same techniques described for cleaning volume controls and switches. If the earphone works, but the speaker doesn’t, then dirty speaker contacts in the jack might be the issue. Plugging in an earphone can help you diagnose this problem. For this to work properly the contacts need to be clean. When the plug is inserted it disconnects the speaker. When the earphone plug is removed both contact points touch, sending the sound to the speaker rather than to the earphones. Dirty/faulty Earphone JacksĪ surprising number of dead radios can be brought back to life by cleaning the small metal contacts in earphone jacks. Put some of it in a “pin oiler” bottle and apply it that way.

You can even use liquid rubbing alcohol in a pinch. I like DeoxIT brand spray, but there are many other good ones. If this fails you should try squirting contact cleaner into the volume control. Sometimes simply moving the volume control rapidly back-and-forth ten or twenty times can clean up the two surfaces. Over time dirt and corrosion build up making the connection between the wiper and the coating unreliable. Volume controls are “variable resistors,” which consist of a circular resistive coating (the gray part in the illustration) and a wiper that slides over this material. Sometimes this problem is so bad that you will hear no, or only the scratching noises, making you think that the radio is not receiving signals, and is dead. When you move a volume control knob and hear scratchy, static-filled sounds it is likely due to dirty volume control innards. Dirty or damaged terminals will silence a radio. Old batteries were prone to leaking corrosive goo that forms an insulating insulator on the metal parts, preventing contact between the battery and terminals.

VINTAGE TRANSISTOR RADIO REPAIR PORTABLE

Batteries, Holders and Terminalsīattery holders are probably the main enemy of old portable radios. As always, practice on less valuable radios until you feel confident. If you have never done these things, they are fun and easy to learn.Īppendix Two shows you the skills you’ll need. You might need to do some soldering and desoldering. You don’t need to understand much radio theory or any engineering formulas to do many common AM transistor radio repairs.

Vintage transistor radio repair