MohawkUS
1000+ Head-Fier
I recently took ownership of a La Figaro 332C amp with the understanding it has a problem involving the headphone jack. It's unknown exactly what the fault is but it is effected by wiggling the headphone cable in the socket. It's a known issue that the jack on these may need to be resoldered. This will be my first time doing DIY/Repair. Pictures I took of the inside of my amp: https://imgur.com/a/q973Lny
Safety questions first:
1. It's my understanding I need to drain all filter capacitors to safely operate inside an amplifier. The purple caps are obviously the power supply filters, do I need to deal with the green or white(output capacitors?)
2. Are the resistors bridging the purple caps for self-discharge purposes?
3. Whats the proper technique when testing for voltage/draining capacitors such as the purples where I can't reach the terminals of each individual cap? Where exactly should I connect each multimeter probe?
4. I should work with the amplifier unplugged from the wall completely correct?
Diagnostics(Using multi-meter):
5. How can I determine if the fault is due to wiring, PCB, or a mechanical fault in the jack?
6. Will I need a pair of headphones plugged in when probing with the multi-meter?
7. Is trying to get a stable read of said headphones impedance between each channel/ground an acceptable way of testing for the location of the loose connection?
8. What are the various wires/solder points around the HP jack connected to? I see a red, blue, and yellow wire along with solder pads marked S, G, R, 2, 3, 1. Doesn't a HP jack only have 3 connections(Left, Right, Ground?)
9. Any advice in diagnosing this problem? Do I seem on track or am I missing anything important?
Safety questions first:
1. It's my understanding I need to drain all filter capacitors to safely operate inside an amplifier. The purple caps are obviously the power supply filters, do I need to deal with the green or white(output capacitors?)
2. Are the resistors bridging the purple caps for self-discharge purposes?
3. Whats the proper technique when testing for voltage/draining capacitors such as the purples where I can't reach the terminals of each individual cap? Where exactly should I connect each multimeter probe?
4. I should work with the amplifier unplugged from the wall completely correct?
Diagnostics(Using multi-meter):
5. How can I determine if the fault is due to wiring, PCB, or a mechanical fault in the jack?
6. Will I need a pair of headphones plugged in when probing with the multi-meter?
7. Is trying to get a stable read of said headphones impedance between each channel/ground an acceptable way of testing for the location of the loose connection?
8. What are the various wires/solder points around the HP jack connected to? I see a red, blue, and yellow wire along with solder pads marked S, G, R, 2, 3, 1. Doesn't a HP jack only have 3 connections(Left, Right, Ground?)
9. Any advice in diagnosing this problem? Do I seem on track or am I missing anything important?