Pioneer Sx1010 Repair - Diodes
- Thread starter 70smidfiguy
- Start date
70smidfiguy
Active Member
70smidfiguy
Active Member
Left
4 - (57.x)
3 - (-54.x)
7 - same as 3 above
Right
4 - (57.9v)
3 - (-54.x)
7 - (not wired)
Interesting in that the voltages were rising almost like a clock with about 8 sec between increments
Pin 7 on the right channel looks like it was never wired. (Not since I got the receiver)
These readings are direct (not on DBT)
4 - (57.x)
3 - (-54.x)
7 - same as 3 above
Right
4 - (57.9v)
3 - (-54.x)
7 - (not wired)
Interesting in that the voltages were rising almost like a clock with about 8 sec between increments
Pin 7 on the right channel looks like it was never wired. (Not since I got the receiver)
These readings are direct (not on DBT)
I read your past posts.
Mark was talking of another circuit that might be pulling down the regulated voltages.
You could disconnect each feed from the power supply board and see if the +-56v supply stabilizes.
Start with pin 15 and recheck the +-56 voltages on the PS.
I remove the pin from the boards using a hot solder iron, heating the pin from the tip/top. Once the solder is melted from the heat transfer through the metal pin, I push the pin out using the iron. You might have to modify the tip or use an old solder iron.
Don't be tempted to unwrap the wire-wraps.
Mark was talking of another circuit that might be pulling down the regulated voltages.
You could disconnect each feed from the power supply board and see if the +-56v supply stabilizes.
Start with pin 15 and recheck the +-56 voltages on the PS.
I remove the pin from the boards using a hot solder iron, heating the pin from the tip/top. Once the solder is melted from the heat transfer through the metal pin, I push the pin out using the iron. You might have to modify the tip or use an old solder iron.
Don't be tempted to unwrap the wire-wraps.
70smidfiguy
Active Member
Before I start removing the pins on the PS these are my readings:
PS 15 = 33.x v
PS 14 = 57.x v
PS 13 = 36.x v
PS 11 = -25.x v
PS 10 = -53.x v
PS 9 = -12.x v
PS 8 = 13.x v
PS 6 = 6.x v
On to next step.....
PS 15 = 33.x v
PS 14 = 57.x v
PS 13 = 36.x v
PS 11 = -25.x v
PS 10 = -53.x v
PS 9 = -12.x v
PS 8 = 13.x v
PS 6 = 6.x v
On to next step.....
70smidfiguy
Active Member
I did some comparisons to other posts on this receiver. Looks like my PS voltages are close.
The only concerning voltage that I can see is my PIN 15 at 33.x which looks high compared to below.
"Pin 8 - (13.4) 13
Pin 9 - (-13.0) -11
Pin 10 - (-56.0) -53.6
Pin11 - (-24.0) -21.6
Pin 13 - (35.0) 36
Pin 14 - (56.0) 57.8
Pin 15 - (24.0) 27.6"
and
The only concerning voltage that I can see is my PIN 15 at 33.x which looks high compared to below.
"Pin 8 - (13.4) 13
Pin 9 - (-13.0) -11
Pin 10 - (-56.0) -53.6
Pin11 - (-24.0) -21.6
Pin 13 - (35.0) 36
Pin 14 - (56.0) 57.8
Pin 15 - (24.0) 27.6"
and
70smidfiguy
Active Member
For clarity on this post:
" read your past posts.
Mark was talking of another circuit that might be pulling down the regulated voltages.
You could disconnect each feed from the power supply board and see if the +-56v supply stabilizes.
Start with pin 15 and recheck the +-56 voltages on the PS.
I remove the pin from the boards using a hot solder iron, heating the pin from the tip/top. Once the solder is melted from the heat transfer through the metal pin, I push the pin out using the iron. You might have to modify the tip or use an old solder iron.
Don't be tempted to unwrap the wire-wraps."
My PS voltages on PIN 14 and PIN 10 are 57 and -53 respectively, when you say "stabilize" are your referring to the that fact that they both are not 56v exactly? or just the variance between them?
Cheers
" read your past posts.
Mark was talking of another circuit that might be pulling down the regulated voltages.
You could disconnect each feed from the power supply board and see if the +-56v supply stabilizes.
Start with pin 15 and recheck the +-56 voltages on the PS.
I remove the pin from the boards using a hot solder iron, heating the pin from the tip/top. Once the solder is melted from the heat transfer through the metal pin, I push the pin out using the iron. You might have to modify the tip or use an old solder iron.
Don't be tempted to unwrap the wire-wraps."
My PS voltages on PIN 14 and PIN 10 are 57 and -53 respectively, when you say "stabilize" are your referring to the that fact that they both are not 56v exactly? or just the variance between them?
Cheers
Pins 10 and 14 are the pre-stage Amplifier supplies. They have to be within a close voltage tolerance. A 4 volt difference between them is not good. Since both amps are behaving the same (Wide DC imbalance) points to a PS issue OR another customer/user circuit using the PS feeds. Like the EQ or Tone/control amps. They might be drawing down the voltage for the amps to operate properly.
By removing the feeds to the external circuits you can determine if the draw is from the other circuit boards or a power supply problem.
The biggest issue is weather you can remove the feeds as I described in an earlier post and not damage the PS board in the process.
I'm sure you can do it!
By removing the feeds to the external circuits you can determine if the draw is from the other circuit boards or a power supply problem.
The biggest issue is weather you can remove the feeds as I described in an earlier post and not damage the PS board in the process.
I'm sure you can do it!
Last edited:
70smidfiguy
Active Member
After removing Pin 15 I have 57.x v on Pin 14 and -53.75v on pin 10
Then, remove pin 11.
70smidfiguy
Active Member
same voltages with 15 and 11 pulled.
70smidfiguy
Active Member
15, 13, 11 all pulled, same voltages.
70smidfiguy
Active Member
Sorred missed you on that last one, 15,13, 11, 9 all pulled same voltages 57.x v on Pin 14 and -53.75v on pin 10
Thanks for your time, I really do appreciate it.
Thanks for your time, I really do appreciate it.
70smidfiguy
Active Member
As a reminder, that is with the driver boards in and using resistors on the outputs and on direct power, no DBT.
The only things not replaced on the PS supply are some of the diodes and resistors although they all look fine.
The only things not replaced on the PS supply are some of the diodes and resistors although they all look fine.
What is the voltages on D8,9 with respect to chassis ground? They are 32V zener diodes, so should be fairly close to 32V.
You can check the resistances of R5-10 as well, with power off of course.
