Pioneer SX-1010 no sound

[nbndtrain]

nbndtrain, were those off readings done with the transistors out of circuit? Remember from the testing thread, in circuit can skew the readings.

And are you going to pull (mark the positions and what came from where first!!) the output transistors and test them?

They were done in circuit. Are you saying I should start removing the transistors from the board to test? (Labelling first, etc) Or something else? I am not sure I know exactly what needs to be done to test out of circuit. And want to be sure I am clear.

 

[markthefixer]

They were done in circuit. Are you saying I should start removing the transistors from the board to test? (Labelling first, etc) Or something else? I am not sure I know exactly what needs to be done to test out of circuit. And want to be sure I am clear.

Yes, although it will be somewhat academic, with the transistors out it makes no sense to not put improved replacements in, but checking the resistors they were connected to with the transistors out of circuit becomes very important for eventual success.

We've done it before with excellent results.

 

[nbndtrain]

Happy Birthday MTF.

I removed and tested most of the transistors from the 2 amp boards and posted out of circuit results above. (Edited last results post) My iron stopped working great, so leaving the last one for tomorrow.

I also am not sure which the output transistors are. There are 8 to-3 transistors on the big heatsink in the back. Is it all of them?

 

[markthefixer]

Happy Birthday MTF.

I removed and tested most of the transistors from the 2 amp boards and posted out of circuit results above. (Edited last results post) My iron stopped working great, so leaving the last one for tomorrow.

I also am not sure which the output transistors are. There are 8 to-3 transistors on the big heatsink in the back. Is it all of them?

Yes, those are all the output transistors.


The results are much more consistent now. Nothing glaringly bad stands out.

Making the toasted 2.2k (red red red) resistor in the center of the board a bit more puzzling.
(the ones in the corner point towards damaged output transistors).
The toasting makes me think that Q7 & Q9 had been stressed, even though they read well enough on a gross test.


What is it's resistance reading with one leg disconnected?

 

[nbndtrain]

R23 Right Board = 2.2k (pulled one leg up)
R23 Left Board = 2.2k (pulled one leg up)

Output transistors:

Left channel

1 PNP:
black lead to base, red lead to collector, result = 598
black lead to base, red lead to emitter, result = 598
red lead to base, black lead to collector, result = OL = No conduction
red lead to base, black lead to emitter, result = OL = No conduction
black lead to emitter, red lead to collector, result = 000
red lead to emitter, black lead to collector, result = 000

2 PNP:
black lead to base, red lead to collector, result = 586
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = OL = No conduction
red lead to base, black lead to emitter, result = OL = No conduction
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction

3 NPN
black lead to base, red lead to collector, result = 000
black lead to base, red lead to emitter, result = 000
red lead to base, black lead to collector, result = 000
red lead to base, black lead to emitter, result = 000
black lead to emitter, red lead to collector, result = 000
red lead to emitter, black lead to collector, result = 000

4 NPN
black lead to base, red lead to collector, result = OL = No conduction
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = 585
red lead to base, black lead to emitter, result = 622
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction

Right channel

1 PNP
black lead to base, red lead to collector, result = 003
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = 003
red lead to base, black lead to emitter, result = OL = No conduction
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction

2 PNP
black lead to base, red lead to collector, result = 001
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = 001
red lead to base, black lead to emitter, result = OL = No conduction
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction

3 NPN
black lead to base, red lead to collector, result = OL = No conduction
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = 534
red lead to base, black lead to emitter, result = 599
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction

4 NPN
black lead to base, red lead to collector, result = 006
black lead to base, red lead to emitter, result = 006
red lead to base, black lead to collector, result = 006
red lead to base, black lead to emitter, result = 006
black lead to emitter, red lead to collector, result = 000
red lead to emitter, black lead to collector, result = 000

 

[markthefixer]

It looks like these are out of circuit readings, correct?

If so, they are toast. No surprise.

No big deal, the replacements are:
........534-4662 to-3 mica insulators $0.16 each.................
863-MJ21193G pnp to-3 250v 16A 250W 4mhz 8-75hfe $4.56
863-MJ21194G npn to-3 250v 16A 250W 4mhz 8-75hfe $4.23

 

[nbndtrain]

It looks like these are out of circuit readings, correct?

If so, they are toast. No surprise.

No big deal, the replacements are:
........534-4662 to-3 mica insulators $0.16 each.................
863-MJ21193G pnp to-3 250v 16A 250W 4mhz 8-75hfe $4.56
863-MJ21194G npn to-3 250v 16A 250W 4mhz 8-75hfe $4.23

I did pull them out to test. You can have the 2 good ones if you want them. Not sure if you would, or if questionable originals would ever be installed in a project.

What are the next steps? Wife is out for a few hours, expecting twins in August, feeling the time crunch!

 

[markthefixer]

Nope, two "good" ones are highly suspect, being in circuit when the others were destroyed - they were probably in a race to failure and the other ones won.

Time to get replacement parts. you will see from the prices vs shipping why getting extras / spares makes sense.

Q1 Q2 Q3 2sa726 to-92 bce 50v .1a .12w 100mhz 500hfe >>> KSA992
512-KSA992FBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.05 ea

Q5 Q6 2sc1451's: to-39 npn ebc 150v 0.5a .7w 150hfe 130mhz
512-KSC3503estu to-126 ecb 300v .1a 1.2/7w 150mhz 40-320hfe $0.28 ea


Q4 2sb528 (bias circuit): to-202? bce 130v .8a 1/10w 55-300hfe ?mhz
512-KSA1381es x to-126 ecb 300v .1a 1.2/7w 150mhz 40-320hfe $0.27 ea


Q8 2sb528 (pre-driver): to-202? bce 130v .8a 1/10w 55-300hfe ?mhz
512-KSA1220AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.37

Q7 2sd358 (pre-driver): to-202? 130v .8a 1/10w 55-300hfe ?mhz
512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.38

Q10 2sa740 (driver): to-220 bce 150v 1.5a 25w 40-140hfe 8mhz
512-KSA940 pnp to-220 bce 150v 1.5a 25w 4mhz 40-140hfe $0.51

Q9 2sc1448 (driver): to-220 bce 150v 1.5a 25w 40-140hfe 8mhz
512-KSC2073TU npn to-220 bce 150v 1.5a 25w 4mhz 40-140hfe $0.53

Q12 2sa733 to-92 ecb 60v .1a .25w 200hfe 180mhz
512-KSA992FBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.05 ea

Q11 2sc945 to-92 ecb 60v .1a .25w 90-600hfe 150mhz
512-KSC1845EBU (ln)to-92 ecb 120v .05a .5w 100mhz 150-800hfe $0.18 ea

outputs:
2sa747a to-3 pnp 140v 10a 100w 30hfe 15mhz
2sc1116a to-3 npn 140v 10a 100w 30hfe 10mhz
........534-4662 to-3 mica insulators $0.16 each.................
863-MJ21193G pnp to-3 250v 16A 250W 4mhz 8-75hfe $4.56
863-MJ21194G npn to-3 250v 16A 250W 4mhz 8-75hfe $4.23

------------------
amp caps:
0.56uf MAYBE (production variations) 5989-100V.56-F $0.53 ea
10uf 16v 647-UPW1H100MDD 10uf 50v $0.15 ea
330uf 6v 647-UPW1A331MPD 330uf 10v $0.20 ea


prot ckt:

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

Q6 2SC945-Q
512-KSD1616ALBU to-92 ecb 160v 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


I'm still digging for the four trim pots, two single turn 500 ohms for bias
652-3362P-1-501LF

and two 25 turn 2k ohms for offset

Power Amplifier adjustment pots: 2.2k offset, 500 bias

bourns 3386 single turn sealed
652-3386H-1-501LF 500 ohms @ $1.29 ea
652-3386H-1-222LF 2.2k ohms @ $1.29 ea

bourns 3266 12 turn sealed (lays closer to board, may be unreachable?)
652-3266P-1-501LF 500 ohms @ $2.94 ea
652-3266P-1-202LF 2000 ohms @ $2.94 ea

 

[nbndtrain]

Great list. Thank you. Have most in my cart with plenty of spares, just a few questions.

C1 on my amp boards are 0.68uF, not 0.56uF. Is DME1P68K-F or 647-UPM1HR68MDD correct part #? Or is that not for C1?

Let me know what your final recommendation is for the bias and offset pots. I am a little confused with that part of your post. Sounds like 652-3362P-1-501LF is correct for bias though.

Should I also order the 2 UNITED CHEMI-CON - 36DA183F075BB2N - CAP ALUM ELECT 18000UF, 75V, SCREW, along with the 5989-250V2.2-F bypass caps? Or is more testing in order first?

Also what about power supply caps? Or is that jumping ahead?

 

[markthefixer]

C1 is sometimes different - (that's why the MAYBE)
use 667-ECQ-V1H684JL $0.32 ea

I'm still sorting out the bias and offset pots - physical mounting factors and direction of adjustment are paramount. The bias pot you mention (652-3362P-1-501LF) is the best choice, and we COULD go with single turn 2K pots 652-3362P-1-202LF (not 222LF, not in stock) but they would be a bit touchy getting the offset zeroed. No more touchy than the original, but what the hay.

I would order the 5989-250V2.2-F bypass caps, but the 18000uf caps may be ok, the bad output transistors could have been clamping the voltage down. That's why I wanted to do a bit more testing before the boards got pulled, because powering up like that is risky. We would have disconnected a few wires at the big caps or just pulled the output transistors without bothering the amp board.

It does make sense to include the power supply parts in the order, and wait until the amp is working before upgrading the power supply.

I'll get a under 5(? w/o shipping) buck list together to do the power supply pass transistors and a few resistors. That's how I conquered maddarts power supply problem.

I should have just stressed that from the start.

Q4 2sb507
one 512-KSA940TU_Q pnp to-220 bce 150v 1.5a 25w 4mhz 40-140hfe $0.54

Q1 Q7 2sd313
two 512-KSC2073TU npn to-220 bce 150v 1.5a 25w 4mhz 40-140hfe $0.54 ea

Q8 2sc1384 (ecb)
one 512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.40

Q5 Q6 2sa628 (BCE)
two 512-KSA1013YBU to-92 ecb 160v 1a .9w 50mhz 160-320hfe $0.17 ea

Q2 Q3 2sc869 (bce not ecb)
two 512-KSC2383YBU to-92 ecb 160v 1a .9w 50mhz 160-320hfe $0.17 ea

D8 D9 wz-032
two 512-1N5257B Fairchild 33 V, 0.5W zener $0.05 ea

D10 wz-014
one 512-1N5244B Fairchild 14 V, 0.5W Zener $0.05

two ten ohms 1/4 watt metal film 660-MF1/4DC10R0F 0.06 ea
one 3.3 ohms 1/4 watt metal film 660-MF1/4DC3R30F 0.06

was the power supply recapped?
ok, here's the caps:
C7 & C8 470uf (80v) 100v 647-UPW2A471MHD $1.87 ea
C10, C11 100uf (63v) 100v 647-UPW2A101MHD $0.87 ea
C12 & C13 100uf (35v) 63v 647-UPW1J101MPD1TD $0.37 ea
C14 47uf 50v 647-UPW1H470MED $0.25
C18 1000uf (35v) 50v 647-UPW1H102MHD1CV $0.98
C19 220uf (16v) 35v 647-UPW1V221MPD $0.41
C20 & C21 2200uf 10v 647-UPW1A222MHD $0.80 ea

extra parts just in case somebody's looking :
D1 D2 D3 D4 SIB01 100v 1amp
D5 D6 D7 1S1885 100v 1amp
512-1n4004 conventional rectifier 1a 400v $0.06 ea

But I haven't checked them for availability.

 

[nbndtrain]

Here is what is backordered. Recommended alternatives?

Q2 Q3 2sc869 (ecb)
two 512-KSC2383YBU to-92 ecb 160v 1a .9w 50mhz 160-320hfe $0.17 ea

C7 & C8 470uf (80v) 100v 647-UPW2A471MHD $1.87 ea
C10, C11 100uf (63v) 100v 647-UPW2A101MHD $0.87 ea
C12 & C13 100uf (35v) 63v 647-UPW1J101MPD1TD $0.37 ea
C14 47uf 50v 647-UPW1H470MED $0.25
C18 1000uf (35v) 50v 647-UPW1H102MHD1CV $0.98
C20 & C21 2200uf 10v 647-UPW1A222MHD $0.80 ea

 

[markthefixer]

Here is what is backordered. Recommended alternatives?

Q2 Q3 2sc869 (bce)
two 512-KSC2383YBU to-92 ecb 160v 1a .9w 50mhz 160-320hfe $0.17 ea

C7 & C8 470uf (80v) 100v 647-UPW2A471MHD $1.87 ea
C10, C11 100uf (63v) 100v 647-UPW2A101MHD $0.87 ea
C12 & C13 100uf (35v) 63v 647-UPW1J101MPD1TD $0.37 ea
C14 47uf 50v 647-UPW1H470MED $0.25
C18 1000uf (35v) 50v 647-UPW1H102MHD1CV $0.98
C20 & C21 2200uf 10v 647-UPW1A222MHD $0.80 ea

Q2 Q3 512-KSC2383YTA
C7 C8 470uf 80v 647-UPM1K471MHD
C10 C11 100uf 63v 647-UPW1J101MPD6 $0.38 ea
C12 C13 100uf (35v) 50v 647-UPW1H101MPD $0.28 ea
C14 47uf (50v) 63v 647-UPW1J470MPD $0.28
C18 1000uf (35v) 50v 647-UPW1H102MHD $1.13
C20 C21 2200uf 10v 647-UPW1A222MPD6 $0.68 ea

 

[nbndtrain]

Replacement for R30? (2nd white one from top) It is bad on the left board. Tested out of circuit.

 

[Majoryyz]

Nbntrain, You certainly have your hands deep into that reciever! You couldn't have a nicer teacher/tech than mark, he helped me out with directions and lists that saved me from pulling my hair out My first reciever was the SX-1010 I bought in 1975. It has all the bells & whistles with 100 watts. What else could you want?? Mine drove brand new HPM-100's. Boston sure sounded great on that system!! Looking foward to following your progress.

 

[markthefixer]

Replacement for R30? (2nd white one from top) It is bad on the left board. Tested out of circuit.

0.5 ohms 5 watts

71-CP5J-0.5 $0.49 ea

 

[nbndtrain]

0.5 ohms 5 watts

71-CP5J-0.5 $0.49 ea

Huge order placed. Looking forward to the next steps. I would really like to be able to find these components myself. Searching Mouser for 5w 0.5 ohm wirewound did not even bring that part number up for me.

Closest I was able to find is 280-CR5-0.5-RC. Would that work as well?

 

[markthefixer]

Huge order placed. Looking forward to the next steps. I would really like to be able to find these components myself. Searching Mouser for 5w 0.5 ohm wirewound did not even bring that part number up for me.

Closest I was able to find is 280-CR5-0.5-RC. Would that work as well?

That's from Xicon, and I have had the two of them side by side and the Xicon disappointed me in just it's appearance alone (sloppy construction), so I wasn't going to delve deeper into it's characteristics to see what other deficiencies there were, especially with only a $0.10 difference in price - might be fine for something experiencing occasional loads over a few years - but I just wasn't comfortable using or recommending it for hard working gear (think that party where it's turned way up, and if it pops - lot's of embarrassment ) over 20 - 30 years.

I think I have 8 of the Xicons I probably will never use.

 

[nbndtrain]

Parts received and organized. Installed new R23, R30, R34, R35, R36 on the left board, and R23 on the right board. What are the next steps?

 

[markthefixer]

I sometimes forget to mention thermal paste and mica insulators. Did I?

Installing the new power transistors (oval) on the heat sinks would be a good first step.

When finished, all 3 leads of each should be isolated from the heat sink.

There is a recess that the power transistor sockets fit into on the heat sink - if not, when tightened the socket could be destroyed.

Use a thin layer of thermal paste on each side of the mica insulators. There should be minimal squeeze out, it is intended to fill microscopic gaps to eliminate air voids.

Remember ... outputs:
2sa747a to-3 pnp 140v 10a 100w 30hfe 15mhz
is replaced by:
863-MJ21193G pnp to-3 250v 16A 250W 4mhz 8-75hfe $4.56


2sc1116a to-3 npn 140v 10a 100w 30hfe 10mhz
is replaced by:
863-MJ21194G npn to-3 250v 16A 250W 4mhz 8-75hfe $4.23

a double check is that the pnp transistor collectors are connected to the - big capacitor's terminal and the npn transistor collectors are connected to the + big capacitor's terminal.

 

[nbndtrain]

Ordered mica, had silicone paste (non conductive) New outputs are in, and insulated from the heatsinks.