u/IIBIMISII

Picked up this kraftwerk cassette over a month ago and it was a bit more than I would have liked to have paid, but it kept calling to me from the shelf. Much to my chagrin, the cassette played unpredictably and incredibly slow and would not roll smoothly. Took it apart. Cleaned and checked. Put it back together. Same thing. Took another crack at it a couple weeks later. Still no joy. Would literally stop the mechanism from spinning. For the $15 I paid - this was incredibly irritating.

Decided to try a felt pad replacement this morning. Cracked open Kenny G as a donor. Someone had gifted it to me as a gag gift. No hate, just not my cup of tea. Wouldn’t you know this Kraftwerk tape is now running absolutely perfectly now and I can actually listen to the damned thing!!! Turns out it was the pressure pad. I’m so pumped.

Kenny’s soul will always live on as part of radio-activity. Good night, sweet prince, and flights of angels sing thee to thy rest.

Had issues with my Sony Walkman with some crazy warbling sounds (check previous posts.) Couldn’t figure it out. Decided to try and find a cheap donor unit. Scored one on eBay for a moderate price. Transferred everything over from my “crappy” unit over into the new one. Had to pull the 3D printed spring hook and the belt over into the new unit as well as the volume knob and faceplate - kept the original case as it was in much better cosmetic condition. At this point servicing this thing feels like routine. Now, I have a Frankenstein unit with parts shared between the two portables.

I kept having REALLY low audio and couldn’t figure it out. Decided to replace some caps. Wouldn’t you know my dumb ass was putting 3v into the unit when it requires 6v to operate? Felt so dumb troubleshooting low audio for a couple hours until I finally realized I was using incorrect voltage. Folks. Check the voltage. It ain’t gonna run or sound right if you don’t!

At any rate. I’m happy to report that my Sony Walkman is up and running again and hopefully will remain in service for years to come. Happy to finally have it all together in one piece rolling tape.

That’s two W’s in a row. Still can’t figure this Panasonic rx 5150 out.

I’m posting this in hopes someone can help me troubleshoot. I also want to add context from a previous discussion that didn’t lead to a fix. Aside from the squealing mentioned there, that post describes my issue almost exactly.

Previous thread: https://www.boomboxery.com/forum/threads/new-owner-of-rx5150-left-channel-very-weak.28052/

Issue

Picked up a Panasonic RX-5150 with a very weak right channel.

Left channel: strong and clear

Right channel: ~10% volume

What I’ve Found / Fixed So Far

Unit originally only played properly when the record mute switch was depressed

→ Fixed by addressing record switch

Record mute slider was stuck

→ Cleaned with DeoxIT and worked it free

→ Playback now works normally without toggling rec mute

Cleaned all accessible pots and switches (2x with DeoxIT):

Volume

Balance

Bass / Treble

Radio / Tape switch

Other accessible controls

Reflowed balance pot solder points

Cleaned headphone jack (ISO + DeoxIT)

→ No bent pins

→ Audio passes correctly, but right channel is still low

Repaired cracked LED meter / TPS board

→ Bridged broken traces

→ TPS seek and lighting now working

Voltage selector is set correctly

Current Symptoms

Weak right channel on:

Tape

Radio

Headphones

Built-in speaker

Balance knob fully right does not restore normal volume

Loudness button works (changes tone), but doesn’t fix channel imbalance

TPS button works, but no effect on issue

Moving / twisting headphone plug causes no change

Important Test Result

Line-out is perfectly balanced (L/R).

Ran line-out into another boombox line-in

Monitored via record mode

Both channels are equal

This suggests the source/preamp section is fine up to line-out.

What Seems Ruled Out

Tape head issue

Source selector/front-end issue

Voltage selector issue

Speaker itself

Headphone jack alone

LED/TPS board as root cause

Typical dirty control issue

What Seems Most Likely

Fault after the line-out split

Right channel power amp/output stage issue

Possibilities:

Bad capacitor / transistor / resistor in right channel path

Cracked trace or bad solder joint in amp/output section

Note: the user in the linked thread recapped the board and didn’t fix it, so caps alone may not be the issue.

Complication

Accessing the solder side of the board is difficult, and I’d prefer not to disturb the radio dial string unless absolutely necessary.

Questions

Has anyone actually fixed this exact single weak channel issue on an RX-5150?

Since line-out is clean, does this strongly point to the AF power amp/output section?

Are there any known common failure components on this model for this symptom?

Appreciate any insight. This one’s been a tough one to figure out.