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  1. 73's de Edd

    Distorted audio on an old transistor radio cassette

    You certainly seem to have marked all of the transistors correctly. With only three left to have completely marked all of them I feel that you will get them correct also . You can keep your meters negative probe at the emitter of either VT4 or VT 10 for all of your measurements . Then you just...
  2. 73's de Edd

    Marshall MA100C problem

    Sir Blackwellefty . . . . . . In checking out the progress, I now see the confirmation of all good fuses by your readings. With no blown fuses, I was intending on you then passing right to a power up to confirm the units 3 power supplies output voltages. BUT, I now see that you went on and...
  3. 73's de Edd

    Large 7-Segment LCD Display

    Out of ALLLLLLLLL of these links, somewhere, there must be what you want. Just watch . . .as there are a few LED types mixed in...
  4. 73's de Edd

    Distorted audio on an old transistor radio cassette

    Sir Richard9025 Look vewy-vewy-vewy carefully and you will see that 13 and 14 are being the SAME common ground connections that constitute a foil trace that runs around just about all of the PCB. Specifically . . . look at your very last photo submitted, and at the right bottom corner and...
  5. 73's de Edd

    Denon AVR 1804 amp won't switch on

    You are doing great . . .just one more test and I will explain all of that circuits function . For this you replace the collector back to where it was connected and then lift the base so that it floats with no connection to it , just as the collector was being treated previously. Then I am...
  6. 73's de Edd

    Need Help with Radio Shack Kit Project

    This will possibly be a better copy for online consulting: https://dl.dropboxusercontent.com/u/1687434/RadioShack%20160%20in%20One%20Electronic%20Project%20Kit.pdf
  7. 73's de Edd

    Denon AVR 1804 amp won't switch on

    Looking at the schema above . The emitter is connected to ground so it HAS to be 0 VDC. The voltage at the base will be whatever the junction voltage results in after the voltage division of R159 and R160 are when being applied across a semiconductor base junction to ground. Any info on the...
  8. 73's de Edd

    Hitachi AXM67 Stereo Repair/Small Modification

    I did confirm that the unit did not use the other Panaplex type as mentioned. It uses blue backlighting, behind a transmissive LCD screen, as evaluated from the photo of another unit being seen lit up. Pass me all of the larger IC chips I.D. s and I can evaluate functions and root out the...
  9. 73's de Edd

    Distorted audio on an old transistor radio cassette

    Sir Richard9025 . . . . . . If experiencing electrolytic capacitance decline the first and most likely suspect of weak and distorted sound coming from that unit is being the PINK C35. Next choice after that would be PINK C14 If declined capacitance is causing poor power supply decoupling check...
  10. 73's de Edd

    Denon AVR 1804 amp won't switch on

    WHeeeeeew . . . . . . . . .we didn't need that dalliance to the side. In not using the 1-2-3- numbering aspect of the Q151 transistor. I am now expecting that the collector lead is free floating and that the base is connected and that the emitter is at ground buss potential.. In that case...
  11. 73's de Edd

    Marshall MA100C problem

    . Sir Blackwellefty . . . . . . .Hmmmmmmmm . . .now . . . shouldn't that be Lefty Blackwell ? First operation at hand will be to get those tubes wrapped up in towels and put in a shoebox. You will need DEEEEEP pockets, to replace those EL34s if rolling off the bench and to the floor. I...
  12. 73's de Edd

    Marshall MA100C problem

    I hope it was / is retrievable as I just got schematic in hand and was was just about to help you. THAT is quite a piece of electronics to TRASH ! 73s de Edd
  13. 73's de Edd

    Hitachi AXM67 Stereo Repair/Small Modification

    Sir Benjo . . . . . Initially . . . as per . . . Whereas . . . . I KNOW for a fact . . . that instead . . .it is being a ferrite antenna that used for the reception of your AM radio stations portion of the receiver. Your designated BLUE circles markups are the RF tuning adjustments...
  14. 73's de Edd

    Denon AVR 1804 amp won't switch on

    . Sir bushtech . . . . . . .. I can see the + 15.76 voltage originating from RED 8 and back flowing through the D154 8.2 volt rated zener and then thru R160 and then ending up at the Q151 base. BUT your Q151 emitter is connected to the same buss as your meters ground, which equates to 0...
  15. 73's de Edd

    Denon AVR 1804 amp won't switch on

    Does that RED 4 now have close to that 5.6 VDC on it, with that transistor collector lifted ?
  16. 73's de Edd

    Denon AVR 1804 amp won't switch on

    . Sir Dave . . . . . . Yesterday his juke box blew da fuse . . . .ICP-N15 opened up . . .ergo . . . .nuttin' got past our now assigned RED 1 test point. Sir bushtech . . . . . . . Well doesn't that beat all ? RED 4 should have 5.6 Volts on it unless either Q151 is turned on and its...
  17. 73's de Edd

    Denon AVR 1804 amp won't switch on

    . You say . . . . . Since B and E leads are side by side, a clean, shiny standard small screwdriver tip should be able to temporarily create a short between them for you.
  18. 73's de Edd

    Wall wart replacement

    Sir C4reynol . . . . . . . Should that be my problem to solve I would get one of the triple adapters shown at the left by virtue of its plastic construction. The ones to the right are no-no s due to HDPE construction medium or molecular nylon construction. They wont adhere to and FIRMLY...
  19. 73's de Edd

    Denon AVR 1804 amp won't switch on

    Base to emitter
  20. 73's de Edd

    Denon AVR 1804 amp won't switch on

    CONDITIONS: With an unpowered set, and with your DVM being in its DIODE test mode: Q151: I am not getting a dead short between base and emitter but DMM does not show 0L but 1681 That range of 1681 is exactly what I would expect a good transistor to read. CONDITIONS: Now you must have...
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