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Pioneer SX-1250

what i worry about is the popping and cracking in left channel and it has better offset than the channel that doesn't pop or crack, which is right channel
 
Reread my post #40. I added while you posted. The popping or cracking noise could be the input differential however MTF also say BIAS circuit can make the noise too.
 
ok, thx, but my heatsink isn't getting scorching hot, can still lay my hand on it and not burn me

i don't have a dbt or any of the old style bulbs to make 1 to test it, care to coach me on where i should use the dmm to test the mv's on the bias? thanks a lot
 
just tested pin 7 (pos) and pin 19 (neg) and got around 107mv's on left channel and
01.5mv on right channel
 
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xXColdShotXx said:
i just tested stabilizer board and got +65.2v from 17(pos) and 12(ground),
got -91.2v from 12(ground) and 16(neg)
Click to expand...

These pin numbers do not make sense, the +65v is good if it is a regulated voltage, while the -91v IF it is a regulated voltage line, is way too high and could be causing High voltage breakdown on any number of transistors.

The reason why one channel is affected and the other isn't is the individual voltage tolerances of the transistors - one may be ok, the other not, with the increased voltage.

what is the aaa-nnn number of the board you are measuring on? awr-106???

removable cards:
stabilizer assembly awr-106 only has 15 pins... all along one edge ground is pin 12, measure pins 11 and 13
protection assembly awm-091 only has 14 pins... all along one edge , no negative voltage to measure here.
power amp assy awh-048 has pins on two sides, 1 to 6 on one end, 6 to 18 on the other. ground is pin 14, measure pins 12 and 15

edit - OK, my bad, they are test pins on the circuitry....
 
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i got 75.3v between 11(pos) and 12(neg) and 75.3v between 13(pos) and 12(neg)

just measured pins (on stabilizer board) 17(pos) and 12(ground on power amp board) and got -16.4v and pins (on stabilizer board) 16(pos) and 12(ground on power amp board) and got 140.1v

tested pins 12(ground on p. amp bd.) and pin 15(pos on p. amp bd.) and got 152.1v
 
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xXColdShotXx said:
i got the pin# from sm page 30 of 94. I didn't adjust anything, just tested the mv's and v's
Click to expand...

Ok, first I see where your original measurements came from, and I was wrong, I overlooked test pins on the pc board that were not reflected in the schematic diagram.

The measurements should be +65 (which is ok) and -65 (which is -91.2 an d s too high).

and the rest of your posts are driving me cross eyed......
pins specified without a board specified are useless.

use the bare metal chassis as your ground, not the board pins. if the ground is messed up so are the readings.

I'm THROUGH for tonight - I'll sort you out tomorrow.
 
ok, thanks for your help, if you have a pic with pin locations on it for me to test i will do it that way it'll be easier for both of us. see ya later, thanks again

edit: tested pin 15(pos on p. amp bd.) and chassis as ground and got 76v

Edit2: i tested pin 15(pos on awh-048.) with pin 14(ground on awh-048.) and got 76v, but when
i test pin 15(pos on awh-048.) with pin 12(ground awh-048.) i get 152v. there could be something wrong with
pin 12(ground awh-048)
 
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It's the negative voltage I am concerned about. If it's magnitude is too large.
 
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what we have here is a failure to communicate.

PLUS The edit2 text did NOT exist when I posted.

unless I explicitly tell you otherwise, DO NOT remove the black DMM lead from the bare metal chassis connection which IS the ultimate ground reference.

The first measurement with the red lead on the awh-048 board pin 15 of +76 volts DC was correctly done, and is correct for the unit.

the second measurement
but when i test pin 15(pos on awh-048.) with pin 12(ground awh-048.) i get 152v. there could be something wrong with pin 12(ground awh-048)
Click to expand...

Pin 12 is NOT ground, it is the negative voltage I wanted measured.
Pin 14 is the ground.

I think you are using the word ground where you should be just saying "the black multimeter lead". The meter does NOT have a ground, just two wires/probes that are distinguished by colors.

your DESIRED measurement protocol is red lead on the awh-048 board pin 12
and black lead to the chassis reference (OR the awh-048 board pin 14 would be permissible IF I let you.)

This is the RAW dc speaker power.

go to the stabilizer assembly awr-106, and read one at a time with the red lead, the test pins #16 & #17 I overlooked before.

Then go to the connector on the opposite side of the board and read ALL these voltages:1, 2, 3 (skip 4 and 5) 6,7,8,9,10,11,12,13,14,15 one at a time with the red probe - while keeping the black probe connected to the bare metal chassis ground.
 
Readings from awh-048(power amp board on right side of receiver looking front to back) all pins tested with red lead dmm
and black dmm connected to chassis for ground
pin 1 - 0v
pin 2 - 0v
pin 3 - 0v
pin 4 - 66.5v
pin 5 - -91v
pin 6 - 26.5v
pin 7 - 0v
pin 8 - 0v
pin 9 - 0v
pin 10 - 0v
pin 11 - 00.4v
pin 12 - -75v
pin 13 - 0v
pin 14 - 0v
pin 15 - 75.4v
pin 16 - -92.2v
pin 17 - 66.5v
 
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well, the failure to communicate worsens......

(it is seven months past April fools day, I hope this is just incomprehension)

go to the stabilizer assembly awr-106, and read one at a time with the red lead, the test pins #16 & #17 I overlooked before.

Then go to the connector on the opposite side of the board and read ALL these voltages:1, 2, 3 (skip 4 and 5) 6,7,8,9,10,11,12,13,14,15 one at a time with the red probe - while keeping the black probe connected to the bare metal chassis ground.
Click to expand...

I specifically excluded making readings on pins 4 and 5 as to not confuse you by having you switch from DC volts to AC volts....

pin 4 - 66.5v should be no reading AC power input
pin 5 - -91v should be no reading AC power input
Click to expand...



pin 1 - 0v -62v raw dc speaker power out
pin 2 - 0v +62v raw dc speaker power out
pin 3 - 0v ground
pin 4 - 66.5v should be no reading AC power input
pin 5 - -91v should be no reading AC power input
pin 6 - 26.5v +85v raw dc in
pin 7 - 0v +23v raw dc in
pin 8 - 0v +5.4v regulated dc out
pin 9 - 0v +13.5v regulated dc out
pin 10 - 0v +25v regulated dc out
pin 11 - 00.4v +65v regulated dc out
pin 12 - -75v ground
pin 13 - 0v -65v regulated dc out
pin 14 - 0v -25v regulated dc out
pin 15 - 75.4v -87.5v raw dc in
pin 16 - -92.2v -65v regulated dc out test pin
pin 17 - 66.5v +65v regulated dc out

it is starting to look to me like you calling an amplifier card the stabilizer card. and have the first 6 measurements 1 to 6 reversed 6 to 1 .
I am starting to distrust everything you are doing.

I do not type in awr-106 because I like the sound of the clicking keys, that is a UNIQUE IDENTIFIER stamped and printed ON THE BOARD I WANT MEASURED. I do this so there is NO confusion about what is to be measured.

So find the board with awr-106 printed on the component side and make the measurements I requested.
 
all those reading were done from the power amplifier board, awh-048
and i looked at the sm for the 1 - 15 pins, tested all pins with red lead dmm and black dmm lead to chassis

i did mention before that i am a noob when it comes to working on this stuff

pins 16 and 17 were read from stabilizer board awr-106, sorry about that
i am in process of getting the reading from 1 - 15 on stabilizer board awr-106 too

readings from awr-106(stabilizer board right side of receiver looking from front to back)
red lead connected to pins 1 - 17, and black lead to chassis for ground
pin 1 - -91.6v
pin 2 - 1.1v
pin 3 - -91.1v
pin 6 - 24.6v
pin 7 - 13.9v
pin 8 - 5.6v
pin 9 - 24.6v
pin 10 - 90.8v
pin 11 - 0v
pin 12 - 0v
pin 13 - 0v
pin 14 - 75.2v
pin 15 - -75.2v
pin 16 - -92.2v
pin 17 - 66.5v
 
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tested awm-091(protection circuit board on left side of receiver looking front to back)
red lead connected to pins 1 - 14, and black lead to chassis for ground
pin 1 - 0v
pin 2 - -73.7v
pin 3 - +73.7v
pin 4 - 0v
pin 5 - 0v
pin 6 - 0v
pin 7 - 0v
pin 8 - 0v
pin 9 - 0v
pin 10 - +26.4v
pin 11 - 0v
pin 12 - 1.1v
pin 13 - 0v
pin 14 - 66.7v
 
tested awr-107(power supply board on bottom of receiver)
red lead connected to pins 1 - 13, and black lead to chassis for ground
pin 1 - 0v
pin 2 - 0v
pin 3 - 0v
pin 4 - 0v
pin 5 - 0v
pin 6 - 0v
pin 7 - 0v
pin 8 - 26.4v
pin 9 - 90.8v
pin 10 - -92.1v
pin 11 - 0v
pin 12 - 0v
pin 13 - 51.2v
 
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15>>pin 1 - -91.6v -87.5v raw dc in
14>>pin 2 - 1.1v -25v regulated dc out
13>>pin 3 - -91.1v -65v regulated dc out

12xx ground
11xx +65v regulated dc out

10>>pin 6 - 24.6v +25v regulated dc out
9>>pin 7 - 13.9v +13.5v regulated dc out
8>>pin 8 - 5.6v +5.4v regulated dc out
7>>pin 9 - 24.6v +23v raw dc in
6>>pin 10 - 90.8v +85v raw dc in

5>>pin 11 - 0v should be no reading AC power input
4>>pin 12 - 0v should be no reading AC power input
3>>pin 13 - 0v ground
2>>pin 14 - 75.2v +62v raw dc speaker power out
1>>pin 15 - -75.2v -62v raw dc speaker power out

pin 16 - -92.2v same as pin 13 -91.1v -65v regulated dc out

pin 17 - 66.5v same as pin 11 +65v regulated dc out

This is hopeless. I THINK you have power supply board problems, but I cannot get readings I can use from you. I have spent MORE time with this thread in fruitless pursuit of clarity than I EVER had with any other thread.

When I figured out that you probably had read the connector block pins 6 through 10 backwards, I thought I could at least decipher things on the power supply regulator awr-106 board. but as soon as I tried the same idea on pins 11 through 15, it fell apart.


So, here is my LAST TRY:

The diagrams showing the boards are from the perspective of the FOIL side, the BOTTOM side of the board where the pins are numbered 15 to 1 going left to right. There are NO components down here, just foil and solder joints.

You are probably looking at the boards from the perspective of the TOP side of the board where all the components are mounted.

On that side the pins are reversed, numbered 1 through 15 left to right.

The tip off is that the pins are grouped in connectors: 1,(small gap),2,3 then 4,5 then 6,(gap),7,8,9,10 then 11,(gap),12,13,14,15
USE those connector groupings to visually differentiate the pin positions.

JUST read the power supply awr-106 board for now - with things wrong with it, reading the other boards right now really doesn't matter.


If it is this difficult just communicating the initial diagnostic readings, replacing capacitors will be worse, and replacing transistors is a guarantee of failure.

edit- a few more ideas...
 
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Here's my last try
AWR-106 red lead 1-17, and black lead connected to chassis as ground
pin 1 - -75.8v
pin 2 - 76v
pin 3 - 0v
pin 6 - 92.1v
pin 7 - 25.2v
pin 8 - 6v
pin 9 - 13v
pin 10 - 25.1v
pin 11 - 66.8v
pin 12 - 0v
pin 13 - -91.8v
pin 14 - 1.1v
pin 15 - -92.2v
pin 16 - -91.8v
pin 17 - 66.5v
awr-106 description.jpg

hope this is right this time, really would like to get this stereo going again
 
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