Getting ready to fix and recap my SX-1010

[Rock&Roll]

My SX-1010 stopped working properly this week. It's never been serviced, so it's no surprise. In months previous, it would frequently drop out audio on the left channel. Jiggling the volume would fix it. I have already been through and thoroughly deox'ed the pots and switches. From what I read here this problem is commonly attributed to some transistors on the AWR-054. This week, the problem developed to point that sizzling and crackling could be heard on the speakers, even with the pre-amp decoupled from the amp. So, i've had to put this horse in the stable for me to get to work on it.

After reading a few of the SX-1010 posts here, I went ahead and did what I saw MTF advising others to do. So here's some power supply voltage readings:

AWR-054
pin 8 = +12.86V
pin 10 = -58.4V
pin 13 = +32.68V
pint 14 = +58.2V

AWM-062
pin 2 = -13.59V
pin 11 = +33.2V
pin 1 = 0.00V
pin 3 = 0.00V

pin 12 = 7.3VAC

As well, I also took measurments on the AWR-054 transistor #Q8

Looking from the printed side of the 2sc1384:
+33.3V | +38V | +34.1V


Outside of wondering what those voltage readings imply, I also and questioning some of the info I reading in my SX-1010 manual. (purchased from stereomanuals.com).

The first capacitors I looked up were C52, C50, C49, and C51 on AWR-027 (tone control) All four of these caps are listed in the manual as 47uF 16V, when the ones on the board are 100uF 16V. Should I trust the manuals specs, or trust what is on the board? This is not a modification by a previous owner.

Lastly, I know to replace all of the polarized electrolytics. However, do I need to be replacing any of the other type of caps like the Mylar, Styrol, or Ceramics? And if so, what is the rule of thumb for replacing these other types of caps with modern ones?

Thanks in advance for your input. The information in old posts here is extremely valuable.

 

[Rock&Roll]

Compiling Parts List:

______________________________________________________________________________________________________
Main Caps:

Source 1:

SX-1010 Power Supply caps: http://www.newark.com/united-chemi-con/36da183f075bb2n/aluminum-electrolytic-capacitor/dp/06H1271

Note that the bulging of the plastic cap on the top doesn't really mean a lot, other than the plastic cap is bulged. It's the business end that's important.

______________________________________________________________________________________________________
AWG-027:
Caps list from MTF (Everything stocked):

647-USR1HR33MDD 0.33uF 25v>50v c:1,2 $0.21
647-USR1H2R2MDD 2.2uF 25v>50v c:13,14,47,48 $0.21
647-USR1V4R7MDD 4.7uF 35v c:15,16,23,24,31,32,39,40 $0.20
647-USR1E100MDD 10uF 16v>25v c:25,26,41,42 $0.22
647-USR1E470MDD 47uF 16v>25v c: 49,50,51,52 $0.27
647-USR1A101MDD 100uF 10v c:7,8,29,30,45,46 $0.27

______________________________________________________________________________________________________
AWR-054:
Rebuild List from MTF (Everything stocked): http://www.audiokarma.org/forums/showpost.php?p=2638283&postcount=5

The power supply's 512-KSC2682YSTU has been obsoleted, use the 512-KSC2690AYS I listed first

______________________________________________________________________________________________________
AWG-062:
Upgrades List From MTF, Updated with info from below:

You can order these from mouser.com:
Q6 512-KSD1616ALBU to-92 ecb 160v 1a 0.75w 160mhz 135-400hfe $0.09
Q7 512-KSC2690AYS to-126 ecb 120/a160 1.2a 20w 155mhz 35-320hfe $0.40

one: C6 100uf/16v (100/35) 647-UPW1V101MPD $0.15 protection circuit timing capacitor
one: C5 4.7uf/25v (4.7/50) 647-UPW1H4R7MDD $0.23 protection circuit ac power on signal integrator
two: C1, C2 0.22uf /10v (0.22uf/50v) 598-DSF050J224 $0.50 ea over-current integrators. polyester film capacitors!!!
two: C3, C4 330uf/25v (330/25) 647-UPW1E331MPD $0.51 ea
one: new part 512-1n4004 conventional rectifier 1a 400v $0.06 ea

The other transistors (Q1-Q5) in the protection circuit won't need changing. You are ADDING the 1n4004 diode to prevent what has already happened to you from happening again, every time the relay turns off, the magnetic field's energy has to go somewhere, so it makes a negative voltage pulse that destroys a little bit of the Q7 junction every time, the diode shunts this energy away from the transistor, at the cost of a few MILLISECONDS more time for the relay to disengage...
Pioneer did the diode thing on newer and higher end models as part of the design later on.

______________________________________________________________________________________________________
AWH-032:

Caps (All are >= stock voltage values):
1x (C1) 647-UPM1HR68MDD 50volts 0.68uF
1x (C2) 647-UPJ1H1R5MDD 50volts 1.5uF
1x (C8) 647-USR0J331MDD 6.3volts 330uF

Transistors:
2x (Q5, Q6) 512-KSC2310YBU NPN TO-92L ecb 150v .05a .8w 100mhz 40-240hfe $0.11 ea

______________________________________________________________________________________________________
AWF-013:

Caps (All are >= stock voltage values):
2x (C1, C2) UPW1H2R2MDD 50volts 2.2uF
2x (C5, C6) UPW1A471MPD 10volts 470uF
2x (C9, C10) UPW1E101MED 25volts 100uF
2x (C19, C20) UPW1H101MPD 50volts 100uF
2x (C11, C12) UPW1E100MDD 25volts 10uF
1x (C21) UPW1E221MPD 25volts 220uF

 

[hpsenicka]

I second the recommendation to do a thorough cleaning before getting out the soldering iron.

Removing the jumpers will help isolate whether the problems are in the pre-amp or amp section of the receiver.

If you have another pre-amp available, you could even feed the amp from a known working pre-amp for a more definitive test.

 

[markthefixer]

There are various 1010 posts that can be mined for parts numbers etc...
Then repost / quote them so that they can be updated for parts obsolescence etc...

There's a sx-750 capacitor replacement thread that is current, look to that for a format to post a list of ALL the electrolytic caps in a 1010, and I'll add the parts numbers if you are interested in a total recap. When it's done in that format, I can work through the list rather quickly, instead of plodding through it, looking everything up. Less than an hour, versus hours....

Just the electrolytic caps get replaced, the others you named don't need it. The parts list CALL then electrolytics.

For more information on Capacitors, read Carve it's posts of the tuning fork guides:
for capacitors:
http://www.audiokarma.org/forums/showpost.php?p=3012505&postcount=11
the entire thread:
http://www.audiokarma.org/forums/showthread.php?t=249745

Removing the jumpers isolated the crackling to the power amps. The voltage readings are fine, and the 0.000 on pins 1 & 3 of the awm-062 protection board don't indicate a DC problem YET....

The strongest candidates for the noise are the two 2sc1451 transistors (Q5 & Q6, ecb triangular layout) on each amplifier card. They don't have the best repuation. They can be replaced by (mouser.com):
512-KSC2310YBU NPN TO-92L ecb 150v .05a .8w 100mhz 40-240hfe $0.11 ea

Headphones are the best indicator of common mode (mono) sizzling and cracking because they sound like they're in your head - no stereo effect. You problem is most likely both channels are now acting up, and the sound in the phones will have a wider field. Common mode noise (mono) would be a power supply problem.

 

[markthefixer]

sigh.......
old posts..........


The protection board's Q6 & Q7 are different

Q6
512-KSD1616ALBU to-92 ecb x60v 1a 0.75w 160mhz 135-400hfe $0.09
edit 2/7/2010 this 60v 1616 is FINE here I originally thought it was 160v

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

The power supply's 512-KSC2682YSTU has been obsoleted, use the 512-KSC2690AYS I listed first

 

[Rock&Roll]

Was just reading that very "old" post, ZeroJunk. Thanks for the repost though. And thanks for the P/N update, MTF.

I had no problems finding all the parts on the list for the AWR-054 power supply board, using the supplied mouser part#'s.

One question I'm not finding a direct answer for in old posts in how to source a replacement for the main caps. The closest thing I've found on my own efforts have been these high-dollar beauty's: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=338-1266-ND. For one, they seem a tad expensive. But, other than that, is there a better alternative I should know about?

 

[markthefixer]

Same problem as gyrene's, physical size of newer caps is smaller (mounting bracket considerations etc), plus wiring attachment details or conversions are critical (screw, snap in, wire wrap etc).

 

[rhomanski]

Hi everybody,
I too am starting to recap a sx-1010. I found a panasonic cap at digikey pt. no. p13204-nd that is the same physical size as the original main caps. I plan on affixing wire wrap posts to the bottom leads to attach the wires and resistor. It has 5 posts, one not used that can be removed. The others are shorted just like the original caps. My idea is to get posts from mouser pt. no.575-1097005, cut a slot in the bottom of the pin and crimp it on the cap. It should work fine I hope.
Regards. Ron.

 

[Rock&Roll]

I think I'm somewhere close to a final parts list. I'm going to leave the tuners alone for now.

I've double checked again, and still have trouble resolving the value of four electrolytic on AWG-027 Board

According to MarkTheFixer and my service manual, C49, C50, C51, and C52 are 47uF. However, the ones presently installed (doesn't look modified) are 100uF at those positions.

 

[rhomanski]

Yes, mine has a lot of discrepancies too. I plan to order what's on the boards not what's in the service manual. If you would, please post a cap list with part numbers from mouser, that would save me a lot of time. I plan on replacing the trimmer pots as well with bourns, but am having trouble sourcing them. Mouser has them all, but on two of them they have a min. order of 200 units. Ones all I need. For the 470 ohm I think I can use a 500 ohm. It's a 3386x-1-501lf, the 330k I cannot find anywhere except mouser and they want too high of a minimum order. I'll keep looking though and we'll see.
Regards. Ron.

 

[rhomanski]

As far as the caps the changes have all been higher capacitance or higher voltage. I think these were engineering changes made during the manufacturing run from information they received from service techs in the field. All units are updated from the field reports as long as production is continued.
Regards. Ron.

 

[Rock&Roll]

I believe my list is complete, short of the Bourns pots: http://www.audiokarma.org/forums/showpost.php?p=3212419&postcount=2

 

[rhomanski]

All right, thank you. I also wanted to do the tuner board as well. I'll figure it out.
Have you broken any wires yet? I had one break just pulling the board out from the front panel. So I ordered a tool and some wire. Lucky I had some experience with wire wrapping back in the eighties. I'm thinking more will break before I'm through. I also have an sx-939 to do after this one. So I figure that tool will get a workout. I just finished a sansui 9090 and thought this would be easier, but the more I get into it, it seems just as bad, only different. Good luck.
Regards. Ron.

 

[Rock&Roll]

No, I've been able to get enough slack where I've needed it. It helps to remove the wires from the plastic organizer clips.

 

[markthefixer]

Yes, mine has a lot of discrepancies too. I plan to order what's on the boards not what's in the service manual. If you would, please post a cap list with part numbers from mouser, that would save me a lot of time. I plan on replacing the trimmer pots as well with bourns, but am having trouble sourcing them. Mouser has them all, but on two of them they have a min. order of 200 units. Ones all I need. For the 470 ohm I think I can use a 500 ohm. It's a 3386x-1-501lf, the 330k I cannot find anywhere except mouser and they want too high of a minimum order. I'll keep looking though and we'll see.
Regards. Ron.

Yes, the parts list is the STARTING point, for a visual examination for factory mods. Go with the factory mods as found.

If you start to have problems, this thread will have to be split, it will be too confusing.

First problem: WHAT 330K pot???? the offset is 2.2k and the bias is 470 (for which 500 is fine).

edit: OH, I see, the separation adjust on the tuner. Use a 500k, it's just a variable resistance with the wiper and one end connected together. Watch out - you'll have space considerations. Single turn is fine for this and bias, but a 25 turn (cheaper than a 12 turn if it will fit) for offset is very useful.

 

[rhomanski]

Yeah I've done that as well. This one just broke right at the insulation. I expect it had been vibrated enough over the years to be weak. At any rate it's a short one and easily replaced. Have you done your transistor heat sinks yet? Mine were fairly dried out. Especially the ones on the board on the bottom. That one really needed new grease.
I'd like to see one of the component guy's work up a sticky for the rest of us explaining what to replace these caps with as far as manufacturers part numbers. Like a ceanl means general purpose or whatever. A ceow4 means this. That sort of thing. I think it would help a lot of people. I'm still confused about what to use. On the sansui I just used nichicon pw series. Now I wonder if I messed up in some places. I will send it off to radio x tuners for an alignment this month. I guess I'll have him look it over and see. I've picked up a box that's air force surplus with foam inside and a hard shell, should make the trip fine.
Regards. Ron.

 

[rhomanski]

Thanks Mark, I'll go with a 500k then. You must have posted while I was typing. It's not quite the same as a phone conversation but still very useful.
Regards. Ron.

 

[markthefixer]

EchoWars, myself and others have managed for years not to open wire wraps.



The nicks in the wires (intentionally from the four corners of the sharp square posts) guarantee wire breakage, especially upon the strain of re-wrapping.

Bottom line: Wire wraps - LEAVE THEM ALONE!!!!!!!!!!

 

[markthefixer]

edit: READ Carve-it's tuning fork posts.... THAT'S the guide to reveal Pioneer's engineer's "ground rules".
whole thread:
http://www.audiokarma.org/forums/showthread.php?t=249745
capacitor posts:
http://www.audiokarma.org/forums/showpost.php?p=3012505&postcount=11


A lot of times the ceanl caps won't make much of a difference except in the noise floor of the unit - which I discovered in doing a sa-9500.

So EchoWars 's advice is just fine for almost all of the units below the top of the line stuff.

And the ESR differences and others on some of the other (solid) caps also won't amount to much that can be found on less than top of the line gear, and will be a VAST improvement over what's been there and aged 30 years.

As for as guide... I don't even have that for myself yet.... I'm still re-investigating (reverse enginering ) the engineering behind the circuits as I encounter them.

And these "live" threads that have posts crossing each another are the bane and most stressful part of thefixers existence.

 

[rhomanski]

Okay Mark, I didn't break the wire on purpose. It broke during disassembly. I have no intention of disturbing the others without provocation. Although, I have no choice with the main caps. I intend on lightly soldering those after making them look wrapped. I try to maintain the original look as much as possible as well as refurb the best I can. On the caps I meant like the stacked film and such. Like I said, I replaced all electrolytics with pw series. Now I wonder if I messed it up. Well, except the bipolar ones of course.
Regards. Ron.