pioneer sx 1050 powers up but no sound.

kubotadave

Active Member
SOFT RELAY CLICKS BUT NO CLICK FROM PROTECTION RELAY awm 90 1=0 2=-12.6 3=7.43ac 4=0 5=0 6=0 7=0 8=0 9=0 10=0 11=0 12=62.9 awm103 1=23.4 2=79 3=-80 4=0 5=13.6 6=13.6 7=-12.7 8=-58 9=-29 10=-24 11=-24 12=0 13=26 14=26 15=32.3 16=63.3 17=63.3 18=5.3 19=5.4
 
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Protection pin voltages?
Some are AC and most are DC.
Check the schematic for the proper voltages.
 
Got it. Will have to wait until tomorrow. Very busy.
At first glance. Something is not adding up.
Re-posted for clarity.

AWM-090
1=0
2=-12.6
3=7.43 AC
4=0
5=0
6=0
7=0
8=0
9=0
10=0
11=0
12=62.9

AWM-103
1=23.4
2=79
3=-80
4=0
5=13.6
6=13.6
7=-12.7
8=-58
9=-29
10=-24
11=-24
12=0
13=26
14=26
15=32.3
16=63.3
17=63.3
18=5.3
19=5.4
 
AWM-103? Import unit?

If it were the AWR-103, the voltages appear to be well within tolerances:


AWR-103
1 = 23.4 √ (24)
2 = 79 √ (76)
3 = -80 √ (-79)
4 = 0 √ (GND)
5 = 13.6 √ (13)
6 = 13.6 √ (13)
7 = -12.7 √ (13)
8 = -58 √ (-60)
9 = -29 √ (-30)
10= -24 √ (-25)
11= -24 √ (-25)
12= 0 √ (GND)
13= 26 √ (25)
14= 26 √ (25)
15= 32.3 √ (30)
16= 63.3 √ (60)
17= 63.3 √ (60)
18= 5.3 √ (5.4)
19= 5.4 √ (5.4)
 
The AWM-090 protection board numbers look correct, but more definition is needed for some of the measurements, specifically 4-11:

AWM-090
1 = 0 √ (GND)
2 = -12.6 √ (-13)
3 = 7.43 AC √
4 = 0 (Recheck on 200mV scale)
5 = 0 "
6 = 0 "
7 = 0 "
8 = 0 "
9 = 0 "
10= 0 "
11= 0 "
12= 62.9 √ (60)
 
Unplug both amp boards and see if it comes out of protection. If it does, then plug one in and see if it still does. If not, then that's your problem, probably those outputs and drivers. If it's not the amp board, it's probably the protection board or one of the two power supply boards. I just fixed an SX-1050 that wasn't coming out of protect. Turned out to be a really leaky cap on the underside power supply board.
 
Let’s wait and see what voltages he’s getting on the protection board first.
Still could be several things.
Eastpoint:
Not sure what you define as unplugging the amp boards(?).
 
The AWM-090 protection board numbers look correct, but more definition is needed for some of the measurements, specifically 4-11:

AWM-090
1 = 0 √ (GND)
2 = -12.6 √ (-13)
3 = 7.43 AC √
4 = 0 (Recheck on 200mV scale)
5 = 0 "
6 = 0 "
7 = 0 "
8 = 0 "
9 = 0 "
10= 0 "
11= 0 "
12= 62.9 √ (60)
  1. =0 2= -12.6 3= 7.43 ac 4= 27mv 5=37 mv 6=61mv 7=68 mv 8=4.2mv 9=2mv 10=3.2mv 11=65mv 12=62.9volts
 
Please post voltages readings in this format, makes it easier to interpret.
Nice job so far.

1=0
2= -12.6
3= 7.43 ac
4= 27mv
5=37 mv
6=61mv
7=68 mv
8=4.2mv
9=2mv
10=3.2mv
11=65mv
12=62.9volts

Rebuild or repair the Protection board.
Test the relay. Mouser P/N 653-MY4-02-DC48
The coil should read around 2.2K ohms.
Transistor Q7, the relay driver is a weak point in this circuit. The 2sc1384 is replaced with a robust KSC2690AYS.

protection parts list.
awm-090 c1 0.22 25 cssa x 0.22 50 598-DSF050J224
awm-090 c2 0.22 25 cssa x 0.22 50 598-DSF050J224
awm-090 c3 470 6 cea x 470 10 647-UPW1A471MPD
awm-090 c4 470 6 cea x 470 10 647-UPW1A471MPD
awm-090 c5 2.2 50 cea x 2.2 50 647-UPW1H2R2MDD
awm-090 c6 47 50 cea x 47 50 647-UPW1H470MED
awm-090 q1 2sc869 0 0 0 0 0 512-KSC1845FTA
awm-090 q2 2sc869 0 0 0 0 0 512-KSC1845FTA
awm-090 q6 2sc945 0 0 0 0 0 512-KSD1616AGBU
awm-090 q7 2sc1384 0 0 0 0 0 512-KSC2690AYS
awm-090 d5 eqa01-33r 0 0 0 0 0 512-1N5257B
Relay, protection 653-MY4-02-DC48

You could piece-meal it by replacing the transistors, working your way back from Q7.
Replace the caps and relay as general practice.
 
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Please post voltages readings in this format, makes it easier to interpret.
Nice job so far.

1=0
2= -12.6
3= 7.43 ac
4= 27mv
5=37 mv
6=61mv
7=68 mv
8=4.2mv
9=2mv
10=3.2mv
11=65mv
12=62.9volts

Rebuild or repair the Protection board.
Test the relay. Mouser P/N 653-MY4-02-DC48
The coil should read around 2.2K ohms.
Transistor Q7, the relay driver is a weak point in this circuit. The 2sc1384 is replaced with a robust KSC2690AYS.

protection parts list.
awm-090 c1 0.22 25 cssa x 0.22 50 598-DSF050J224
awm-090 c2 0.22 25 cssa x 0.22 50 598-DSF050J224
awm-090 c3 470 6 cea x 470 10 647-UPW1A471MPD
awm-090 c4 470 6 cea x 470 10 647-UPW1A471MPD
awm-090 c5 2.2 50 cea x 2.2 50 647-UPW1H2R2MDD
awm-090 c6 47 50 cea x 47 50 647-UPW1H470MED
awm-090 q1 2sc869 0 0 0 0 0 512-KSC1845FTA
awm-090 q2 2sc869 0 0 0 0 0 512-KSC1845FTA
awm-090 q6 2sc945 0 0 0 0 0 512-KSD1616AGBU
awm-090 q7 2sc1384 0 0 0 0 0 512-KSC2690AYS
awm-090 d5 eqa01-33r 0 0 0 0 0 512-1N5257B
Relay, protection 653-MY4-02-DC48

You could piece-meal it by replacing the transistors, working your way back from Q7.
Replace the caps and relay as general practice.
 
Thank you so much for all the help.Its been 35 years since ive worked on electronics.The help and guidance shown on this site is invaluable.I have the parts ordered,and cant wait to rebuild.I want to push the contacts closed to see if sound is restored.Would this be a bad idea?
 
Please post voltages readings in this format, makes it easier to interpret.
Nice job so far.

1=0
2= -12.6
3= 7.43 ac
4= 27mv
5=37 mv
6=61mv
7=68 mv
8=4.2mv
9=2mv
10=3.2mv
11=65mv
12=62.9volts

Rebuild or repair the Protection board.
Test the relay. Mouser P/N 653-MY4-02-DC48
The coil should read around 2.2K ohms.
Transistor Q7, the relay driver is a weak point in this circuit. The 2sc1384 is replaced with a robust KSC2690AYS.

protection parts list.
awm-090 c1 0.22 25 cssa x 0.22 50 598-DSF050J224
awm-090 c2 0.22 25 cssa x 0.22 50 598-DSF050J224
awm-090 c3 470 6 cea x 470 10 647-UPW1A471MPD
awm-090 c4 470 6 cea x 470 10 647-UPW1A471MPD
awm-090 c5 2.2 50 cea x 2.2 50 647-UPW1H2R2MDD
awm-090 c6 47 50 cea x 47 50 647-UPW1H470MED
awm-090 q1 2sc869 0 0 0 0 0 512-KSC1845FTA
awm-090 q2 2sc869 0 0 0 0 0 512-KSC1845FTA
awm-090 q6 2sc945 0 0 0 0 0 512-KSD1616AGBU
awm-090 q7 2sc1384 0 0 0 0 0 512-KSC2690AYS
awm-090 d5 eqa01-33r 0 0 0 0 0 512-1N5257B
Relay, protection 653-MY4-02-DC48

You could piece-meal it by replacing the transistors, working your way back from Q7.
Replace the caps and relay as general practice.
Could you tell me how to post the values in this format?Sorry im not great on a computer.
 
It's been 35 years since you've worked in electronics, so other than a little rust and dust, you should be fairly current with the vintage of units we tend to see. Once you get back on the bike and get your balance, you'll be golden.

As for the formatting, simply enter one line, such as " 1 = 0V " then {ENTER} to start a new line/row.

You're not great on a computer? Well, you found this site, and I believe that says SOMETHING about your prowess. :thumbsup:
 
First read post 19 before attempting this procedure.

Make sure the jumpers are installed.
With an input from the FM or AUX and the volume to a min level. Use your DMM in AC range and probe the pins 8 and 11 for a jumping voltage (Black to chassis) indicating the amps speaker output.
While connected to pin 8 or 11, turn the volume up and watch the meter looking for an increase in voltage. Just a little to check the operation.
If the indication looks good, you could jumper the pins:
8 to 9
10 to11
A temporary check only.
 
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My feeling is that the 61/68mV on pins 6 & 7 could be at the threshold of tripping the protection.
 
It could be
Hold off on shorting the pins.
Try to set the DC Balance using the service manual.
You want to get the amp(s) as close to zero volts as it will let you.
 
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