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  1. PoDuck

    9090db goes into protect with only 32mV input signal.

    Okay, I figured it out. When I put the protect board back in, there are 4 blue wires that go to the board. I got two swapped around. One was the wire going to the green diode on the protect light. The other went to the headphone plugs. I'm not sure why exactly that trips the protect...
  2. PoDuck

    9090db goes into protect with only 32mV input signal.

    I rebuilt my protect mode circuit, and my driver board, and I'm having a bit of trouble now. At first, I lost my meters, but it wouldn't go into protect until I applied about 1.2V of a signal. I was getting around 110VAC out of the speaker terminals at this point. I found that a ground wire...
  3. PoDuck

    Sansui 9090db no FM reception

    Okay, what amplitude should the 10.9 Mhz signal be, and where best to inject it?
  4. PoDuck

    Sansui 9090db no FM reception

    Okay, nevermind that. There is no signal in that mess. I'm not sure what that is, but if you look, it's basically no signal at all. Apparently I won't be able to get into it more until tomorrow.
  5. PoDuck

    Sansui 9090db no FM reception

    Okay, I have tested at TP01, which is in a different place on the board than it shows in the service manual, and I get a really dirty signal, but it does seem that the strongest frequency is in the 10Mhz range, but there is noise getting in somewhere. Here is the test point I found: Here...
  6. PoDuck

    Sansui 9090db no FM reception

    I should probably test to see if there is 10.7Mhz there already. I assume I would do that at TP1 on the F-2549 board? I'll do that later today. I made the mistake of not knowing the rules when I got married, so what I want to do on my day off is not of any concern anymore. Apparently, if...
  7. PoDuck

    Sansui 9090db no FM reception

    I did ensure the transistor was installed correctly. I tested all voltages according to the schematic, on all boards. Most voltages were around 9% higher throughout, but if I remember correctly, the voltages on the tuner board were almost all spot on. I wrote them all down, so I can check...
  8. PoDuck

    Sansui 9090db no FM reception

    I have been having a bit of "fun" with this 9090DB, and I've run into another issue someone here might be able to help with. When I bought this unit, I was told that there was no FM reception. Because of that, I decided that it was likely an issue with the front end. When I pulled out the...
  9. PoDuck

    Sansui 9090db no audio from left channel from inputs

    Update on this, in case anyone else has ghostly sound issues with the volume control. I guess it wasn't just a cold solder joint. I left things sit overnight, and when I came in this morning, I found that the left channel was gone again, and putting pressure on the volume control didn't make...
  10. PoDuck

    Sansui 9090db no audio from left channel from inputs

    Okay, after injecting a signal into the left and right channels, and following it along, I found that the signals were both going to the volume control, and only the right signal was coming out. I had cleaned these pots already, so I didn't think much about it, but what I found was that if I...
  11. PoDuck

    Sansui 9090db no audio from left channel from inputs

    I have a 9090db that gets no preamp output on left channel inputs. I plug in a signal to the main inputs, and I get audio on both channels, so the amplifier is working. When I plug in to the right channel, I get sound, but on the left channel, I get nothing. I've cleaned all the pots, input...
  12. PoDuck

    Is it possible to find a transformer for a 9900z

    Wow, that's great to know. I still haven't had the time to get to testing things out myself, and I still hope the outputs of the transformer are okay, but if not, hopefully this information will be helpful. Thanks.
  13. PoDuck

    Is it possible to find a transformer for a 9900z

    Okay, I got it back from him, and he was completely wrong. I don't know what he was thinking, but it wasn't a dead short. It had 1.5 ohms resistance at the power input, which is somewhat lower than I would expect, but not a short. In fact, when I hook it up to the DBT with a 100 watt bulb, it...
  14. PoDuck

    Is it possible to find a transformer for a 9900z

    Just called him and he says that on the power cord, he is getting 0 ohms across the prongs. It should have at least some resistance. Unless there is something wrong with the power cord, it seems to me that is a pretty good sign that it's bad.
  15. PoDuck

    Is it possible to find a transformer for a 9900z

    It's kind of a long story. I got it and the amplifier board was pretty much destroyed. It had legs blown from transistors, blown resistors, and even blown mica caps. I had to replace about half the components on the board. I had handed it off to a shop initially, and he didn't want to accept...
  16. PoDuck

    Is it possible to find a transformer for a 9900z

    I have a 9900z that appears to have a blown transformer. Is this a lost cause, or does someone know some magic about getting a replacement?
  17. PoDuck

    G 4700 worth $200 ???

    I know I'm resurrecting this for little reason, but I was searching for stuff about the 9900z and found this. If you fed that thing a hot supper, be prepared. I just got done working on one. All but three transistors were blown up, as well as a bunch of resistors and caps. You can still get...
  18. PoDuck

    Output transistors keep blowing on SX-2500

    I am sorry I didn't update this at the time. I actually got this problem fixed. The problem appears to have been a cold solder joint. I am not sure what was not making a connection since I didn't find it formulaicly, nor did my eyes pick up on it. I just got so frustrated that I went over the...
  19. PoDuck

    Output transistors keep blowing on SX-2500

    The schematics I have show that module in the main interconnect diagram, but they don't have the schematic for that board. My question is how would that board be reducing the power on a single channel, and not cutting it out altogether? I'll bypass that board and see what happens though. I'll...
  20. PoDuck

    Output transistors keep blowing on SX-2500

    It looks like some cool conversation happened while I was gone. It's been busy on my end here lately. My bench has been consumed with paying work, and I had to go to the auction for my wife's store yesterday, so the pioneer had to move to the side. Got to pick up a traffic light for myself at...
  21. PoDuck

    Output transistors keep blowing on SX-2500

    Other than slight differences, the one I have matches very closely. That one resistor being on the wrong side, and the other two resistors showing the wrong value are the only two discrepancies I've found so far, and they are the same on your images too. Both.
  22. PoDuck

    Output transistors keep blowing on SX-2500

    Anyway, the wife is wanting me to come home, so I guess I'll get started pulling caps and testing them tomorrow, because that's where my mind is at right now. Unless, of course, you can give me another place to look.
  23. PoDuck

    Output transistors keep blowing on SX-2500

    Is it possible that there might be a bad capacitor somewhere acting like a resistor instead of a dead short? That seems to be my other option here I guess, unless you guys have something else.
  24. PoDuck

    Output transistors keep blowing on SX-2500

    Well, considering that I replaced a good chunk of those traces, and I'm confident there are no breaks, the traces shouldn't be bad. As for wrong parts, I'll look, but I don't think so.
  25. PoDuck

    Output transistors keep blowing on SX-2500

    The actual board is a bit different than the one in the SM. R51 is on the wrong side, but it would do the same thing in either place. R17 I get 9.2V across it, and R18 I get 8.8V.
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