• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

pioneer Sx-950 cuts out after warming up

petemoss

petemoss

New Member
I believe sx-950 going into protection. When its cold it takes awhile maybe 10 min. Then if I power up again it might come on for a second or two before cutting out. Is it perhaps relay related issue or?? Thanks for any help you can throw my way!! Pete
 
Register to hide this ad
Not looking at a diagram, but it appears the offset voltage on one channel is marginal and drifts far enough to cause the protection circuit to activate.
 
First read / post the power supply pin voltages, then the protection board's pin voltages.

It could be:
1. power supply
2. an amplifier
3. protection board itself - weak relay driver transistor.

protection rebuild is well documented in here...
 
power supply AWR-101 voltages out of range are: #15 -46.4v should be -19v .......a Q6 problem???

I hope this is right but from the reading I've done the following are the pins that relate to this.(I definitely lack confidence)

AWM-062

#11 36.5v is 35.1v
#2 -13.6v is -12.9
#12 7.5 v AC is 7.2v
#1 and #3 were in the 10 millivolt range
 
Last edited:
petemoss said:
power supply AWR-101 voltages out of range are: #15 -46.4v should be -19v .......a Q6 problem???

I hope this is right but from the reading I've done the following are the pins that relate to this.(I definitely lack confidence)

AWM-062

#11 36.5v is 35.1v
#2 -13.6v is -12.9
#12 7.5 v AC is 7.2v
#1 and #3 were in the 10 millivolt range
Click to expand...

Power Supply

What are the rest of the voltages ?

Pin 15 provides voltage for the phono board

This is not the reason it is going into Protect other problems still

Power Supply AR-101

Pin 2 5.4v
Pin 4 13.5v
Pin 6 51.5v
Pin 9 36.5v
Pin 11 28v
Pin 13 -13.5v
Pin 15 -19v
Pin 14 -51.5v
Pin 17 -49.5v
Pin 18 49.5v
 
Last edited:
Not exactly the format I expected, took digging, but....

Yes - Q6 issue and NOT the problem.

Re: protection board voltages - It's an internal problem, external voltages to the board are good.

If you are curious, look at the base of Q7, if it's over 0.6v or so, it should be on and the relay in.

Check for the -5.1v at C5 minus.

or just replace Q6 & Q7, add the 1n4004 to 9 (anode) and 10 (cathode = banded end) and recap the thing.



from my records:

awm062 board parts

Q1-Q2 2SC869-C
512-KSC2310YBU TO-92 ecb 150v .05a .8w 100mhz 40-240hfe $0.11 ea

Q3, Q4 2SC945-Q
512-KSD1616AGBU to-92 ecb 60v 1a 0.75w 160mhz 135-400hfe $0.09

Q5 2SA733-Q
512-KSB1116AGBU to-92 ecb 60v 1a 0.75w 160mhz 135-400hfe $0.09 (Y,G=200/400)

Q6 2SC945-Q
512-KSD1616ALBU to-92 ecb 60v 1a 0.75w 160mhz 135-400hfe $0.09

Q7 2SC1384-R
512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.40

C1, C2 0.22uf
598-DSF050J224 CDE Metallized Polypropylene Film Capacitors 0.22uF 50V 5% $0.14

C3, C4 330uf 6v 647-UPW1A331MPD 330uf 10v $0.20 ea

C5 4.7uf 25v 647-UPW1H4R7MDD 4.7uf 50v $0.12

C6 100uf 16v 647-UPW1H101MPD 100uf 50v $0.22

don't forget to add the 1n4004 flyback diode to pins 9 (anode) and 10(cathode).

512-1n4004 conventional rectifier 1a 400v $0.06 ea

some of the caps may be old numbers or out of stock.
 
they are:

#2 5.02v
#3 5.05v
#4 13.08
#5 13.11
#6 50.1
#7 50.1
#8 35.6
#9 35.6
#10 36
#11 27.8
#13 -13.1
#14 -50.9
#15 -46.4

Thats all of em. Anything else? Thanks!


Thanks Mark I put up these other voltages before I saw your post. The format meaning I should have put up all the pin voltages? Sorry I'm a greenhorn for sure.That sounds like a plan.I appreciate it!
 
Last edited:
markthefixer said:
Not exactly the format I expected, took digging, but....

Yes - Q6 issue and NOT the problem.

Re: protection board voltages - It's an internal problem, external voltages to the board are good.

If you are curious, look at the base of Q7, if it's over 0.6v or so, it should be on and the relay in.

Check for the -5.1v at C5 minus.

or just replace Q6 & Q7, add the 1n4004 to 9 (anode) and 10 (cathode = banded end) and recap the thing.



from my records:

awm062 board parts

Q1-Q2 2SC869-C
512-KSC2310YBU TO-92 ecb 150v .05a .8w 100mhz 40-240hfe $0.11 ea

Q3, Q4 2SC945-Q
512-KSD1616AGBU to-92 ecb 60v 1a 0.75w 160mhz 135-400hfe $0.09

Q5 2SA733-Q
512-KSB1116AGBU to-92 ecb 60v 1a 0.75w 160mhz 135-400hfe $0.09 (Y,G=200/400)

Q6 2SC945-Q
512-KSD1616ALBU to-92 ecb 60v 1a 0.75w 160mhz 135-400hfe $0.09

Q7 2SC1384-R
512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.40

C1, C2 0.22uf
598-DSF050J224 CDE Metallized Polypropylene Film Capacitors 0.22uF 50V 5% $0.14

C3, C4 330uf 6v 647-UPW1A331MPD 330uf 10v $0.20 ea

C5 4.7uf 25v 647-UPW1H4R7MDD 4.7uf 50v $0.12

C6 100uf 16v 647-UPW1H101MPD 100uf 50v $0.22

don't forget to add the 1n4004 flyback diode to pins 9 (anode) and 10(cathode).

512-1n4004 conventional rectifier 1a 400v $0.06 ea

some of the caps may be old numbers or out of stock.
Click to expand...

I would recap the power supply board also. I listed the transistors for the power supply board. Mark recommends replacing Q5 Q6 and Q7.

All parts listed are in stock.
This list is complete for the protection and power supply boards.

Power Supply Board

AWR-101: C10: 470uF 80v ACH-038: 647-UHE2A471MHD 470uF 100v
AWR-101: C11: 470uF 80v ACH-038: 647-UHE2A471MHD 470uF 100v
AWR-101: C12: 1000uF 35v ACH-039: 647-UPW1V102MHD 1000uf 35v
AWR-101: C13: 1000uF 25v CEA: 647-UPW1E102MPD6 1000uF 25v
AWR-101: C14: 220uF 10v CEA: 647-UPW1V221MPD6 220uF 35v
AWR-101: C15: 470uF 63v CEA: 647-UPW1J471MHD6 470uF 63v
AWR-101: C16: 47uF 16v CEA: 647-UPW1V470MED 47uF 35v
AWR-101: C18: 47uF 50v CEA: 647-UPW1H470MED 47uF 50v
AWR-101: C19: 47uF 35v CEA: 647-UPW1V470MED 47uF 35v
AWR-101: C20: 100uF 63v CEA: 647-UPW1J101MPD6 100uF 63v
AWR-101: C21: 47uF 16v CEA: 647-UPW1V470MED 47uF 35v
AWR-101: C23: 100uF 35v CEA: 647-UPW1V101MPD 100uF 35v

Q2 2SB507
512-KSA940TU pnp to-220 bce 150v 1.5a 25w 4mhz 40-140hfe $0.54

Q3 2SC1318
512-KSC2383YBU to-92 ecb 160v 1a .9w 50mhz 160-320hfe $0.17

Q1,8,9 2SD313
512-KSC2073TU npn to-220 bce 150v 1.5a 25w 4mhz 40-140hfe $0.54

Q10 2SC869
512-KSC2310YBU to-92 ecb 150v .05a .8w 100mhz 40-240hfe $0.11 ea

Q4,6 2SA720
512-KSA1013YBU to-92 ecb 160v 1a .9w 50mhz 160-320hfe $0.17

Mark Heads up this is at End of Life Dammit stock is still available
512-KSD1616ALBU

BOM
512-KSC2310YBU
512-KSC2310YBU
512-KSD1616AGBU
512-KSD1616AGBU
512-KSB1116AGBU
512-KSD1616AGBU
512-KSC2690AYS
598-DSF050J224
598-DSF050J224
647-UPW1A331MPD
647-UPW1A331MPD
647-UPW1H4R7MDD
647-UPW1H101MPD
512-1n4004
647-UHE2A471MHD
647-UHE2A471MHD
647-UPW1V102MHD
647-UPW1E102MPD6
647-UPW1V221MPD6
647-UPW1J471MHD6
647-UPW1V470MED
647-UPW1H470MED
647-UPW1V470MED
647-UPW1J101MPD6
647-UPW1V470MED
647-UPW1V101MPD

Transistors for Power supply
512-KSA940TU
512-KSC2383YBU
512-KSC2073TU
512-KSC2073TU
512-KSC2073TU
512-KSC2310YBU
512-KSA1013YBU
512-KSA1013YBU
 
Last edited:
Mark Heads up this is at End of Life Dammit stock is still available
512-KSD1616ALBU
Click to expand...

sorry, too damn expensive, they jack the price on "end of life's"


512-KSD1616AGBU is just fine. and isn't in any danger..

and a heck of a lot less expensive...

it's a gain code:

R = 40 - 80
O = 70 - 140
Y = 135 - 270
G = 200 - 400
L = 300 - 600

and gain isn't as important where I specify it.

in fact

The d1616 uses Y G L gain codes
while the ksa733 and ksc945 use all the codes: R O Y G L
thus they can be lower gain!!

just to answer the odd question : what is BU and TA

BU = bulk = just a handful
TA = tape = glued onto a tape between two layers of cardboard - it is a heat release glue.
 
Last edited:
Mark
Thanks I updated the BOM with this part

markthefixer said:
sorry, too damn expensive, they jack the price on "end of life's"


512-KSD1616AGBU is just fine. and isn't in any danger..

and a heck of a lot less expensive...

it's a gain code:

R = 40 - 80
O = 70 - 140
Y = 135 - 270
G = 200 - 400
L = 300 - 600

and gain isn't as important where I specify it.

in fact

The d1616 uses Y G L gain codes
while the ksa733 and ksc945 use all the codes: R O Y G L
thus they can be lower gain!!

just to answer the odd question : what is BU and TA

BU = bulk = just a handful
TA = tape = glued onto a tape between two layers of cardboard - it is a heat release glue.
Click to expand...
 
You must log in or register to reply here.
Back
Top Bottom