I picked up a sad Lasonic TRC-931 that was in need of a few repairs. It was $70, but had a siezed power switch, was stuck on AM (broken gear), a broken tape deck, and was very hard to change inputs (another broken gear). I'll log what I've done so far:
before
Every square centimeter of it, inside and out, was like this
Gear #1: Desoldered the switch with my Aoyue 474a++, cleaned out the switch and lubricated it with Super Lube
Trommelmops' milled brass replacement gears to the rescue. I LOVE this kit, I got two gears and it comes with a milled tool for tightening the tiny bolt that attaches it. Beautifully engineered.
Re-attached. The mod is easy if you are experienced at soldering/desoldering, but is absolutely not something for the inexperienced.
Gear #2: also broken but not as bad I guess
Trommelmops again. You need to file down the ends of the original metal shafts with a file. They were attached under pressure and that gives them a lip that needs to be removed before you can fit the new brass gears on
Re-attached
Recapped the radio PCB and started cleaning
I really love how beefy the Lasonic 931 is, but its Chinese capacitors are garbage and are way past their specced lifespan at this point. I'm giving mine a full recap using long-life, 105C rated Japanese caps from Digikey. I'm matching the capacitance of the originals, but using much higher voltage rated caps, since those are what I have on hand from other projects
The original thermal compound on the heatsinks was powder, so I replaced it. This is overkill, but I enjoy the process
Spraying Deoxit in the power switch was enough to fix it
Recapped the front facing/EQ PCB and applied more Deoxit in the sliders & pots
I'm waiting on a few more caps to come in and then I'll re-organize the cables and she'll be done
https://www.youtube.com/watch?v=Ve-OWia2Un8
First test sounds excellent, to me at least. Couldn't find any proper boombox music on the radio, so jazz it is
After 8+ hours cleaning it inside and out, it's starting to come together
Esther was a badass
What's left: finish 10 or so caps left in the recap, do some more deep cleaning, track down antennas, find a battery compartment cover, get rechargeable D cells, and tackle the tape deck one day. I just use line-in for everything so tapes are a low priority. I feel like it deserves to have the deck fixed though.
before
Every square centimeter of it, inside and out, was like this
Gear #1: Desoldered the switch with my Aoyue 474a++, cleaned out the switch and lubricated it with Super Lube
Trommelmops' milled brass replacement gears to the rescue. I LOVE this kit, I got two gears and it comes with a milled tool for tightening the tiny bolt that attaches it. Beautifully engineered.
Re-attached. The mod is easy if you are experienced at soldering/desoldering, but is absolutely not something for the inexperienced.
Gear #2: also broken but not as bad I guess
Trommelmops again. You need to file down the ends of the original metal shafts with a file. They were attached under pressure and that gives them a lip that needs to be removed before you can fit the new brass gears on
Re-attached
Recapped the radio PCB and started cleaning
I really love how beefy the Lasonic 931 is, but its Chinese capacitors are garbage and are way past their specced lifespan at this point. I'm giving mine a full recap using long-life, 105C rated Japanese caps from Digikey. I'm matching the capacitance of the originals, but using much higher voltage rated caps, since those are what I have on hand from other projects
The original thermal compound on the heatsinks was powder, so I replaced it. This is overkill, but I enjoy the process
Spraying Deoxit in the power switch was enough to fix it
Recapped the front facing/EQ PCB and applied more Deoxit in the sliders & pots
I'm waiting on a few more caps to come in and then I'll re-organize the cables and she'll be done
https://www.youtube.com/watch?v=Ve-OWia2Un8
First test sounds excellent, to me at least. Couldn't find any proper boombox music on the radio, so jazz it is
After 8+ hours cleaning it inside and out, it's starting to come together
Esther was a badass
What's left: finish 10 or so caps left in the recap, do some more deep cleaning, track down antennas, find a battery compartment cover, get rechargeable D cells, and tackle the tape deck one day. I just use line-in for everything so tapes are a low priority. I feel like it deserves to have the deck fixed though.
enough gears 
