Pioneer CT-F2121 with a dead left channel

I just checked the points with turquoise arrows and the right channel shows good. The left channel shows open.
 
I put a jumper across the two points (the turquoise arrows) on the left channel and it's working. Can I just solder a wire in or do I have to remove the bad coil first?
 
When you jumperd across the two points, does the Q105 collector voltage drop down from 5.2v to about 3.6v?
 
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That's closer to what it should be, 3.6v. Was that 3.53v AC or DC? Usually the schematic will show the DC voltage.
Do you plan on recording from FM broadcasts, or only vinyl and CDs?
 
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If I record, it will be CDs and vinyl. It'll be mostly for playback of tapes I already made.
 
remove the solder joints and they should just lift out unless they are also glued to the board. or remove the solder from the pins so the traces no longer connect and solder jumper wire to traces
 
Maybe this picture will help. As @tapetech says, completely remove the solder from 5 pads (yellow) on each filter, remove the part, then solder in a jumper wires as shown (pink).

@tapetech, does this look correct?

Screenshot 2025-11-07 082725.jpg
 
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I'm not disputing taking out the filters. I'm going to remove them as suggested. This question is informational, so I can learn more about this work. Why can't I leave them in and just solder across the two traces? Will it cause damage?
 
stushug said:
This question is informational, so I can learn more about this work.
Click to expand...
Here is the schematic for the filter.
  • The five soldered leads are shown in purple circles.
  • If you remove the part and jumper from the input to the output pads, the signal path is fine, but there are a couple of internal capacitors to ground (presumably part of the LC filter) which will also be removed.
  • C125 is still in series to block DC between Q105 & Q107.
  • You should be fine doing this.
Screenshot 2025-11-07 200339.jpg
 
Thanks @dankik. I've changed the belts and tires, cleaned and lubed everything mechanically. Is there anything I should be checking in the electronics to insure the deck is working as it should? Some final steps in this tuneup?
 
Good.
  • If your record volume control causes erratic VU meter movement when adjusting the record volume, a squirt of Deoxit D5 in the Input L/R volume control + rotating it 30+ times should clean that up.
  • Clean the input/output RCA connectors on the back with some >92% isopropyl alcohol to remove any dirt & oxidation.
  • Clean the tape heads with >92% isopropyl alcohol.
  • Check all capacitors for any electrolyte leakage (not to be mistaken with a brown staking compound) and case swelling, which means it's about to go. Replace as needed. (Unless you are doing a full recap, but it sounds like you are a novice so don't attempt it at this time.
  • Make sure that all of the lamps are working (looks like there are 3 lamps).
Enjoy listening to your deck!
 
@dankik and @tapetech Thanks so much for all of your help! It's greatly appreciated when you guys take the time to give specific instructions and then explain why they're necessary. I'm good at mechanical work, I just have to get better at reading schematics and following them on the actual boards. I've done a few recaps on other pieces, 99% electrolytics. I get a bit out of my understanding with other types of caps, I'm not sure why. If I do recap this, I'll do one board at a time so if a problem does come up, it's usually easier to trace my steps. There are two fuse lamps above the cassette tray, one wheat bulb between the VU meters and one for the Dolby indicator, and one red led for the record light. They're all working so I'll leave them alone.
Thanks again!
 
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