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Hello. Yamaha EM200 powered mixer. I have these "221" things, labeled R in the PCB (capacitors are marked with a capacitor symbol). One reads 222 ohm in my multi component tester, the other one reads "unknown or damaged component", so it's open. They look like a capacitor but they are some...

Hello. I'm needing some ceramic or non magnetic screwdrivers to adjust tape decks, and wanted to know of your experience, what works fine for you or which tools to avoid. I see some generic kits not too expensive, but I see the tip is not very long. On the other side, there are some Vessel...

Hello. I need to repair a small power supply. Some capacitors leaked and corroded the copper, quite severe damage. How do you clean or treat this kind of damage. Is there a solvent that works better than others? tried flux, isopropyl alcohol, ethyl acetate, but nothing seems to be very...

Hello. I'm trying to get the right parts for a Yamaha M2 power amplifier, from Digikey. Could you help me to locate these fuse resistors? I get lost in the many options, and I can't find those green resistors I use to see inside the amplifiers when a fuse resistor is indicated. Thanks very much.

Hello. I'm repairing an old radio, and wonder about how easy-difficult would be to modify this output to use 2 Si transistors instead of the original Germanium. The problem I have is very high 100Hz ripple and of course HUM at C74 (2200uF), and perfectly rectified DC after TR15, so my suspects...

Hello. Yamaha obsolete part. The shaft is broken inside the potentiometer. Do you see possible to save the part? Tricks, ideas, are welcome ! Thanks very much!

Hello. The unit in question is a Pioneer SX1500-TD. It came with 2n3055 at the output. One channel blown. Power supply B+ is +65V Original parts on the schematic are 100V Parts, the 2n3055 are 60V transistors. Budget is always an issue down here, so if the 2n3055 could work, I'd leave one...

To-3 mica with 3 small holes:

Hello. I'm troubleshooting a Peavey Bass 400 series, Mark III, with mixed transistors on every board. My question is about these 2 pre drivers Q2 and Q12. The original Peavey part numbers are 100V 4A transistors, but I'm not sure if I need a 4A device for that application. I have some spare...

Hello. While fixing and checking a mixing console, noted that a couple of outputs have "unbalanced" balanced outputs. I mean, the 2 opposite signals have different amplitude respect to gound, but if I measure from Signal+ to Signal-, the amplitide is right. No problem when using them as...

Hello. Servicing a large amp (Moog Synamp, if you are curious), and checking the PS capacitors, i get this image. Positive and negative sides, 50mV/division. Shifted up and down for easier reading. PS voltages are +59 and - 59V DC. Are those peaks normal? Should I do something about that? Diode...

Hello. I'm fixing a modest AKAI GXC-36D cassette deck, it has a voltage selector, but not a HZ selector as seen in bigger machines or RtoR decks (the motor pulley has 2 diameters to change the belt position when running at 50 or 60Hz) The motor runs at 120V AC, with a 1uF capacitor, at 50 or...

Hello. I'd like some guidance, advice, about the best course of action to resurrect a dead M2, sent to me after another tech failed to fix it, many wires disconnected and parts replaced. Long story short, I received an M2 in non working condition, and a bag with output transistors from Digi...

Hello. I'm having a weird problem with a SE-9: Crackling noises and pops, like from a noisy transistor, just in one channel (Right), only when the eq is enabled, and can be muted with the output level control. The noise is obviously in the eq section, but I can't find the culprit. I've replaced...

Hello. I bought a parted out Infinity Qe in 2012 (shipping speaker boxes down here would be too expensive, so I asked the seller to send me just the parts without the cabinets), and finally, 10 years later they are finished. The boxes were made by a local wood worker like 2 years ago. 18mm MDF...

Hello. I see my user name is being followed by "Lunatic member", previously it was "addicted", an so. English is not my mother language so perhaps I'm not understanding these words adecuately, but I don't feel comfortable being named "addicted" or "Lunatic". Can I edit that?

Hello. Have you seen a fail like this? "arcing" TO-220 transistors. The screws also show signs of electrical arcs. Factory original. SKP PA 1300 amplifiers. 2 units with the same problem. In one amp, 3 out of 8 transistors had that problem. Amps with intermittent problems, sometimes working...

Hello, I'm needing the transformer voltages for a Crest CC1800 amplifier, and the service manual doesn't give that information. Do you know the rail voltages of that amp? It has LOW and HI DC rails (and AC windings), which I suppose auto switching on demand. The spec sheet states that the max...

Hello. Bought this hook type probes, I'd like to know the proper way to attach a cable to them... Do I need to disassemble them?

Hello. I'd like to know if some of you have succesfully replaced a Pioneer CT-F900 reel motor. I have a machine that was rebuilt 3 years ago, the motor cleaned and contacts polished, and worked fine for 3 years. Two months ago started to show problems again. Cleaned the motor again, and less...

Hello. Disassembling a cheap boombox (last time I put my hands on something like this, not even a "favor" for somebody), found these plastic ribbon that wasn't doing proper contact (LCD display working in parts). Removed it, to find it's a kind of graphite traces glued to the PCB. I've cut the...

Hello. I need to try a "surgery", soldering a ribbon cable attached to a laser pickup. I wonder what kind of cautions I need to take. I was thinking to add the "solder blob" usually found in new lasers, but I'm not sure if that is a good idea. Thanks in advance. Picts attached:

Hello. I'm looking to buy some 2sc5200 2sa1943 pairs, and checking on Mouser, I see the Toshiba 2sc5200N to-3p are 1/2 of the price of the ON semi 2SC5200OTU to-264. Any reason to buy the more expensive ones? they have a bit higher current or wattage rating, but my thinking is that the Toshiba...

Hello. I finally bought this custom made transformer, 220V input, 220 with center tap (110V) output, 300VA. It's pretty big and heavy, bigger than what you imagine looking at the picts. I'd like to see ideas on how to wire it. Mounted on a wood board? hidden under the bench? with an extension...

Hello. I need to buy a replacement for a rotary solenoid, original part is a Ledex 128264-001 It's fed by 28V, permanent action (it must stay energized, some solenoids have a % duty cycle) I can't find a supplier for this kind of things, a couple of suppliers I've found on the internet didn't...