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  1. KilgoreCemetery

    MPS U56 BJT Replacement Comparison and Options

    Thanks for your help, Harald. The original one doesn't have a heat sink. It goes just before the main output transistors
  2. KilgoreCemetery

    MPS U56 BJT Replacement Comparison and Options

    Oh... that darn pinout... Thanks for mentioning that or I probably would've overlooked it entirely. Are these feedback mechanisms variable or is this something that I'm going to need to modify to keep the circuit stable? Aside from the pinout being different, is there anything that jumps out...
  3. KilgoreCemetery

    MPS U56 BJT Replacement Comparison and Options

    I'm trying to find a proper replacement for an MPS U56 transistor and I'm starting to feel a little lost trying to decipher apples and oranges. First, this is from the power amplifier section of an HH Scott receiver. It goes right before the main output transistors. I've been comparing...
  4. KilgoreCemetery

    Kole Audio TRAX1-5500D Missing Component?

    So, I pulled and tested Q16 (BR 39), and this is what I found:
  5. KilgoreCemetery

    Kole Audio TRAX1-5500D Missing Component?

    That's a good idea! Ironically, Q4 and the missing transistor have the same foot print. There are other identical "BE RJ" transistors in the area, but I don't know enough of what they're doing to tell what they are.
  6. KilgoreCemetery

    Kole Audio TRAX1-5500D Missing Component?

    At least that gives me something specific to research though. My only other concern is, if I find the right part and put it in, how do I know it won't just burn it up? Are the voltages on the pads considered normal for where a transistor would go?
  7. KilgoreCemetery

    Kole Audio TRAX1-5500D Missing Component?

    Ok, I think I have some info.. The pad that has 12V all the time goes through a resistor and takes two different paths. One goes to Q4 (BE RJ) and the other path goes through another resistor, the positive side of a cap, along the underside of the board, and then to IC2. Which is an ST LM393...
  8. KilgoreCemetery

    Kole Audio TRAX1-5500D Missing Component?

    I would guess transistor as well based on the other markings on the board. IC's and diodes have the IC and D prefixes. Figuring out where the other two traces go may be tricky, but I'll see what I can do
  9. KilgoreCemetery

    Kole Audio TRAX1-5500D Missing Component?

    Definitely! Hopefully these help. It's hard to get a good amount of lighting without glare
  10. KilgoreCemetery

    Kole Audio TRAX1-5500D Missing Component?

    I have a mono block amp that won't power on. It doesn't light up at all. I pulled and checked the fuses and verified that they are good. Also, when I supply power, they do have about 12V all the way across. When I first started looking at it, I did find 6 swollen 25V, 220uF capacitors and one...
  11. KilgoreCemetery

    Technics SA-818 FM Muting Problem

    I recently cleaned up and recapped the entire unit. I didn't realize anything was wrong with it until I tried the FM Muting. C117, C119, and C125 are all new Nichicon caps. I found in the service manual that, when adjusting T101, the goal is to have zero volts when probing TP102 and TP103, so I...
  12. KilgoreCemetery

    Technics SA-818 FM Muting Problem

    Everything on this receiver works great except for one little thing. The FM Muting cuts out to the beat of the music or when commercials get too loud. It's not dependent on the actual decibel rating coming out of the speakers, just the incoming FM signal. Like, if it's a quiet song or a mono...
  13. KilgoreCemetery

    Yamaha receiver won't turn on

    My google-fu turned up two more things: 1. You should make sure the impedance selector switch in the back is set properly. Evidently it's easy to get the switch between settings on this model. 2. Pulled this from a different site and the section I found in the service manual about error codes...
  14. KilgoreCemetery

    Yamaha receiver won't turn on

    PS PRT is "Power Supply Protect". edit: It's telling you that there is a 14% voltage deviation
  15. KilgoreCemetery

    Philco Radio Parts Identification

    So before I go on a shopping spree for parts, I just want to confirm one thing. Is uuf the same as pf? I've seen mmf before, but not uuf. Something like this: https://www.digikey.com/product-detail/en/vishay-cera-mite/440LS10-R/BC2757-ND/2687072 ?
  16. KilgoreCemetery

    Philco Radio Parts Identification

    Yep. There are supposed to be two of the metallic cans, but when I got it, there was only one. Took me a while to realized that the Yellow Aereovoz is supposed to take the place of the second can. They changed how it was wired in, though, too. It's supposed to be underneath, between the button...
  17. KilgoreCemetery

    Philco Radio Parts Identification

    I bet it's this black box. I'll have to see if I can get it apart
  18. KilgoreCemetery

    Philco Radio Parts Identification

    The small one has drifted to about 17Ω, and I'm guessing the large one is supposed to be a 150Ω (now closer to 176Ω). Yes sir! That looks to be correct! Hmm... I've seen the letter designation used before to indicate different sections of a multi-can capacitor, but this model has two separate...
  19. KilgoreCemetery

    Philco Radio Parts Identification

    This thing needs a lot of work before I'll put power to it. Lots of cracked wiring! When the time comes, I have a current-limiting setup that I'll use Thanks for all the info, guys! I'll be looking into this more and confirming everything as soon as I can!
  20. KilgoreCemetery

    Philco Radio Parts Identification

    These parts are from a 40-180 console radio that I'm looking to restore. I'm hoping someone on here can tell me what kind of components these are and possibly their values as well. This looks like a foil capacitor covered in wax, but there are absolutely no markings on it: Are these two...
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