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Pioneer SA-505 clicking

Discussion in 'Audio' started by tooter, Feb 17, 2018.

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  1. tooter

    tooter

    36
    1
    Feb 17, 2018
    Hi T
    TP2 &ground is 16.4mv TP£ & Ground is 26.4mv thanks.
     
  2. duke37

    duke37

    5,297
    739
    Jan 9, 2011
    That looks good, will leave further investigation to Edd.
     
  3. 73's de Edd

    73's de Edd

    2,805
    1,175
    Aug 21, 2015
    Sir tooter . . . . .

    Back on day one you say
    " i tested the voltage on the board across the pins where the relay actuator lives and I get 48v "

    The next relay info was being
    after replacing the relay I can only measure 6v across the relay

    On your last requested test, you then came up with nowhere near that 48 volt level.
    " Hi thanks im struggling with the meaning of ripple readings. So i went ahead and swapped the cap and its still dont activate the relay although it tries it clicks on very briefly as soon as i turn it on then releases and tries again but it like its not strong enough to pull it in so i re measured the voltage across the relay coil and i got 10v this time and 18 before the R414 resistor so the voltage has risen but not enough it seems. sorry i couldnt take the measurements you require. "

    So now, the relay coil voltage has risen up from the initial 6 V up to the present 10 V now, so that filter must have experienced time related . . . depletion into a lazy state.
    Can you lift the cathode lead of D201 out of circuit at its foil pad and do the relay voltage test again . .log the now provided supply voltage before R414 and across the relay.
    Replace D201 cathode back into circuit and lift D202 cathode and repeat the voltage tests.
    I am expecting both tests to give the same voltages with no chance of activating the relay armature.

    Will be back tomorrow for Phase II testing.
    This
    condensed and marked up schematic snippet should provide all of our select referencing .
    The
    YELLOW is the specific parts being involved in the units protection circuitry.
    The RED is the over voltage sensing portion.
    The
    BLUE is the over current sensing portion.


    CUSTOM PROTECTION CIRCUITRY REFERENCING . . . .

    upload_2018-2-27_7-15-20.png


    73's de Edd
    .....
     
  4. tooter

    tooter

    36
    1
    Feb 17, 2018
    Hi ed just a quick reply to awnser some of it queries. 1) 48v was measured when relay was removed.
    2) I replaced the relay and it measured 6v.
    3)10v was measured when I replaced the cap you suggested. I will carry out the tests asap and return with the results thanks.
     
  5. tooter

    tooter

    36
    1
    Feb 17, 2018
    Hi edd today I removed the cathode leg of the diodes you requested these are the results.
    removed D201 before it passes through R414 I get a between 11.70v-12.50v the voltage never seems to stabilise jumping up and down.
    after 5.67v-6.30v again up ad down.

    D202 before 8.30v-9.03v again up and down.
    after 4.90v-5.20v again uop and down.
    Idont know how significant the voltage fuctuation is but thought it was worth a mention.
    thanks agian.
     
  6. 73's de Edd

    73's de Edd

    2,805
    1,175
    Aug 21, 2015
    Tir Sooter . . . . . . . .drats! my lys-dexia's kicking in again . . . don't ever grows olds !

    I was just initially covering ALL aspects in the testing of BOTH of those diodes, not really expecting any fault with those diodes,as it would require a RARE opening of a diode junction to have a fault.
    Since . . . . one and then the other diodes contribute in the alternate rectifications of both nodes of an incoming AC power winding of the power transformer. . . .to sum up their outputs as the volltage to then be stored in the now NEW C204.

    I see that this supply ALSO feeds the display LED's associated with the front panels . . . . . PHONO-TUNER-and CD/AUX as well as Tape 1*** and Tape 2***.
    ( ***But there is a slight circuit variance in their supply levels feed. )

    Try a power up with the idea of observing the PHONO-TUNER-and CD/AUX display LED's.
    Now . . . .do the three seem to be of the same brightness as they were w.. a..a..a..y back in 1993 ?
    More importantly would each of them . . .if activated . . .possibly also be showing that same voltage fluctuation . . . resultant dimming . . . and it being at the same rate as the prior volt meter readings fluctuations ?

    Now to the Phase II test which will have you monitoring the power supply side of our now all too familiar R414 820 Ω voltage dropping resistor.
    That may require clip on connections, as you then need to make a temporary connecting of Q405 relay driver transistors BASE to EMITTER . At that instant, the supply voltage monitored should shoot up ot the highest value that you have seen . . . . prior to the test with no relay being in circuit.
    The possibility of C to E leakage of Q405 or any C407 electrolytic capacitor leakage should be our only other fault possibilities.
    TRIPLE CHECK . . .to see that you will be Base to Emitter (Gnd) and NOT Base to Collector connecting !

    (You would see me using the tip of a standard blade . . . pocket sized screwdriver . . . to be making that temporary evaluative connection.)

    Wha..a...a..a..t will we now be finding ?

    73's de Edd
    .....
     
  7. tooter

    tooter

    36
    1
    Feb 17, 2018
    Ok thanks again. Just to get this right.
    1) test voltage across the mentioned leds for voltage fluctuation?
    2) make tempory connections to power supply side of R414 and ground. Connect to volt meter
    3) use a screwdriver to short base to emitter of Q405 transistor.(Not collector and base.
    Just want to be 100% I'm doing the test correct. Thanks
     
  8. 73's de Edd

    73's de Edd

    2,805
    1,175
    Aug 21, 2015
    1) test voltage across the mentioned leds for voltage fluctuation?
    From your description of the upsy-downsy of the voltage of that supply, when DC voltage testing it, I would suspicion that you would see that degree of variance in the change of illumination of the LED's.

    Right-o . . . . . on (2) and (3) . . . . . . and then expecting full DC supply level, with that Q405 not being to conduct and febbly try to engage the relay coil.
     
  9. tooter

    tooter

    36
    1
    Feb 17, 2018
    Hi im a little perplexed with this now i believe what im doing is correct but none of the results seem to be as expected. what idid was solder wires to the base and emitter for Q405 connected the metter to power side of R414 and to the ground of the coil powered on voltage went up to 12v waves up and down creaps up to 18v after a min or 2 then drops right of if i short q405 voltage drops of to 0v then back up if i disconnect them. The leds are all solid no flickering at 2.5v.
     
  10. 73's de Edd

    73's de Edd

    2,805
    1,175
    Aug 21, 2015
    You say . . . . .

    Connected the meter to the power side of the R414 . . . . . . .and to the ground of the coil.

    Correct on the meter + connection , but the meter - goes to the Q405 emitter or any of the several ground connections that it shares.
    Your grounding and ungrounding of the transistor base is producing the expected results, if it is not additionally being leaky.
    Test that voltage again.
     
  11. tooter

    tooter

    36
    1
    Feb 17, 2018
    red and black pos and neg of my meter.
    yel and green Q405 emitter and base
    pic2.jpg
     
  12. 73's de Edd

    73's de Edd

    2,805
    1,175
    Aug 21, 2015
    You have 3 out of 4 correct . . .The black meter negative test point should be same as the green circle OR the equally like neg of C406 or neg of C405 or top lead of very nearby R411.
    .....
     
  13. tooter

    tooter

    36
    1
    Feb 17, 2018
    Hi im realy greatfull for the help so far feer i may have conducted yesterdays test wron so i redone it today with different results sorry.ive attached a pic to show what i did this time.
    purple hows the lifted legs and test- point .(one at a time)
    blue shows left connected.
    red shows +test points hope this is correct.
    results D201-before R414 0V after -3.2
    D202 before R414 0V after -2.3 test1.jpg
     
  14. tooter

    tooter

    36
    1
    Feb 17, 2018
    Ok so redone test 2 and attach pic to show.
    Red +test point
    Black - test point
    yel shows short point.
    voltage was 43.9 before short and 44.2 when yel and black was shorted.
    hope this shows better than i can explain. test2.jpg
     
  15. 73's de Edd

    73's de Edd

    2,805
    1,175
    Aug 21, 2015
    Sir tooter . . . . .

    You got it ! . . . . that supply voltage is now being up into the initial range that you first mentioned.
    Now lets see why your relay won't relay .
    From your earlier voltage readings, from info transferred it seems like your amps audio power output stages are being functional.

    So what I need now is any info from that overload relay . . . . that you now know on a middle name basis.
    I would suspect that there will be some stamped on info, relevant as to its coils resistance or its current pull in milliamperes or I can compute from resistance. Also you might supply the relays whole part number and brand so that I can also look up its pull in and hold voltage / current specs.
    Not interested in any contact specs . . . . only the relays coil info.

    Testing . . . . .
    In a no power on situation, measure the DC resistance of the relay coil as well as the resistance of R414 also, but I expect R to be of a metal film construction and being as stable as a rock.
    Now with your readings already submitted on the Power output stages, to our right honourable and esteemed Sir Duke, I believe that the system will be able to play, we just need to correct this protection relay activation problem.
    Prep up by getting an audio source into, or within the unit, and set your volume knob to its usual normal volume position. Hook up either speakers or headphones.

    Have the relay driver transistors Base and Emitter still connected / shorted so that any attempted incoming base bias voltage will be ignored.

    We want to monitor the supply voltage lines level into R414 as referenced to our prior used meter ground reference.
    You now need to get a test wire connected to ground and use its free end to temporarily connect to the Collector of Q405 relay driver transistor, the relay should thump down as you have heard it do for years and music should come forth.
    If it holds latch for 3-5 seconds , let off on the jumper wire and prepare to do the supply side of the R414 power supply side test to see what the coil loading causes the whole supply to pull down to . . . .when you then activate the relay again.
    Then let off activation of the relay and reposition metering to put meter probes across the coil winding . . . to see what actual voltage the relay coil is now running on.

    Give back all of the summation of queries info..

    As it is, with you having experienced no blown up transistors nor fuses, I classify this situation as being a "soft" failure and highly suspicion the fault to be another "lazy" capacitor in the YELLOW protection circuit area . . . . . . such as you have already found with C206 in the dedicated relay power supply section . . . .(LED's say meeeeee too !.)

    Thasssssit . . . . .

    73's de Edd
    .....
     
    Last edited: Mar 2, 2018
  16. tooter

    tooter

    36
    1
    Feb 17, 2018
    hi quick up date. relay info
    omron G2r-2232p-v
    24vdc
    3a 120vac
    3a30vdc
    ASR-107-O
    that is everything from the relay.
    will be back soon with results.
     
  17. tooter

    tooter

    36
    1
    Feb 17, 2018
    Ok so the results are in. I removed r414 from the circuit and it read 827ohm and the relay was 1093ohm.
    I then proceeded to the setup the amp for further testing. after grounding the colector the relay thumped down as predicted and sweet music came from my speaker ( It was good to hear the old girl again)
    the voltage from the power side of the r414 was 42.8v. I then swaped it to the relay side of r414 and got a sweet 24.2v and then measured the across the coil when activated and got 24.1v. I feel we are making good progress now. I was exited to hear her again.
    summary
    827ohm from r414
    1093ohm from relay
    42.8v relay activated beforer414
    24.2v activated after r414
    24.1v across the coil.
    hope that's everything you asked for.
    Thanks.
     
  18. tooter

    tooter

    36
    1
    Feb 17, 2018
    Hi edd. I would like to say a big thank you. I replaced the q405 transistor and my amp sprung to life and seems to be working great. You went over and above to help me and I'm very greatfull. Thanks.
     
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