Friday, January 20, 2023

Kenwood TH-215A TH-225A HT Repair - Low / No Audio Output

I figured that I may as well post this as it could probably help others. The Kenwood TH-215A and TH-225A are my favorite 2M HT's. There are others in this family as well (TH-315A, 415A, etc which have different bands). Inside they are all basically identical. These radios are rugged, reliable, and inexpensive on the used market. I have also always loved the way they look and have a bunch of these as a result.



Recently a couple of mine had the same symptom develop around the same time, very low or no audio output from the speaker. Opening and debugging one with a heat gun and some freeze spray, there is a group of capacitors near the top of the main board which have gone bad. They all sit next to a BA526 audio amplifier which probably runs a little hot causing the capacitor failure over time. All of these capacitors are made by ELNA, so they used good caps. But these being manufactured from the late 1980s to early 90s is still pretty old and cap failure can be expected. 30+ years was a good run for them.

I ended up replacing all the capacitors in this section, nearly every one had been leaking. After replacing the audio was back to a nice loud volume level. I inspected other capacitors inside the radio but couldn't find any others that were leaking. It probably wouldn't be a bad idea to replace them all in these radios, but in terms of fixing the audio issue, these are all that need to be replaced. Sensitivity and receiving / transmit quality is still great after the fix. 

Replace the capacitors highlighted in yellow


Here are the capacitors I ordered from Digikey, dimensions are the critical spec here as you need to keep them under the original capacitor dimensions to fit in the tight locations. I generally always buy 105 C rated caps, but they were not available in all the values / sizes I needed at this time. I ordered at the price break of 10 of each as I had multiple radios to do and extras are never a bad thing. This is a good time to replace the lithium battery as well. Hopefully others find this helpful to keep these great radios running.