pioneer sx1080 help...

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#42
stereo ok,

turn up volume a bit, turn OFF tone switch and with paperclip touch the inner center conductor of the left channel aux jack.
hear the buzz
with paperclip touch the inner center conductor of the right channel aux jack, hear the other speaker buzz.
 

gene french

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#43
with input in aux mode...nothing connected...
left channel buzzes in off and on positions of the tone control
right channel is silent in both positions...
but, again a slight static when the tone switch is on....down position...
thank you very much
 

gene french

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#45
touching the left aux input in the mono mode sends buzz to both speakers...
touching the left aux input in the stereo mode sends buzz to left speaker at increased volume
touching right aux input in mono mode produces nothing
touching right aux input in stereo mode produce nothing...
still a slight static when the tone switch is on in the down position...
 
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#46
do you have extra interconnect (RCA) cables?

extra cables as shown:

back tape cables.png

in stereo, repeat what you have been doing, with the addition of flipping the tape monitors on as well.

when testing, flip the tape monitor switches(1 and 2) on and off in an OCD fashion, really giving them a workout.
 
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gene french

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#49
with cabling as shown...and input mode set to aux..
in stereo mode...
touching left channel creates buzz...touching right channel is silent
madly flipping the tape monitor switches show no difference in results...except maybe a mild popping sound...
in mono mode
touching center of left aux jack creates buzz in both speakers at a reduced volume...
madly flipping the tape monitor switches show no difference in results...except maybe a mild popping sound...at reduced volume...
 
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#50
ok, that's it for tonight, it'll take me a while to set up for the next step.

what is the make and model (& a pix?) of your DMM.

We will be using it on resistance settings.
 
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#52
That picture you posted of your meters has great resolution,
could you do a similar picture of the bottom of the SX-1080
with it angled a bit (but not a lot) to show some of the green board area that would be shadowed under the front panel lip?

Gives me something to inspect, and to mark more finger hum points on.

no big rush, i'll be back much later in the day, checking for it.

then it will take a while to work on. but it will give me something to continue the finger hum method of troubleshooting.

thanks...
 

gene french

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#53
That picture you posted of your meters has great resolution,
could you do a similar picture of the bottom of the SX-1080
with it angled a bit (but not a lot) to show some of the green board area that would be shadowed under the front panel lip?

Gives me something to inspect, and to mark more finger hum points on.

no big rush, i'll be back much later in the day, checking for it.

then it will take a while to work on. but it will give me something to continue the finger hum method of troubleshooting.

thanks...
howdy...
 

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#55
A quick drop by:
The pictures are great, detail i can work with - except for the shadowed area.
I can see signs of previous attempts on this signal loss.

We need to take that board out of the front panel, insulate the daylights out of it between the components and the bottom of the unit, and operate the unit.

then get a almost straight on down picture showing it resting out of the chassis.
just unscrew the panel mechanical mounts
pull it in about an a few inch(es) or so, and then up.
you have done this if you replaced caps and transistors on it.

This way we will have full view of and access to the circuit patterns on it.

because - wouldn't you know it - the potential problem areas are all hiding in that shadow.
The missing right channel is right next to the edge in spots.

With power off, before insulating and securing it, there are factory jumper wires on it - be sure they are all intact and connected.
(the empty spots are the volume and balance controls.)

s-l1600-3.jpg
 
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#57
ok to run unit upside down for this.

not component side, sorry, pc pattern side of those two boards - one with volume control.

great use of carpet fragments!
 
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