SX-950 Project

Check the wires from the awe-066 tuner board pins 13, 14, 15, 16 to the (located on the back panel) AWX-095 board pins 1,2 3 & 4 for shorts, pinching etc...

Trade C45 and C46 bypass and see if it swaps sides - or just put in two (or four, C43, C44 coupling as well) new 10uF caps.
 
I have pulled C45 and C46 (10uf/16v) out of the circuit. I am attempting to check them with my harbor freight meter which has a capacitance test mode. One cap measures 0.058uf. The other measures 0.13nf.

I only have two 10uf caps on hand. They are 10uf/50v. 647-UPW1H100MDD. Can I use these? They both measure close to 10uf with my cheap meter.
 
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I have pulled C45 and C46 (10uf/16v) out of the circuit. I am attempting to check them with my harbor freight meter which has a capacitance test mode. One cap measures 0.058uf. The other measures 0.13nf.

I only have two 10uf caps on hand. They are 10uf/50v. 647-UPW1H100MDD. Can I use these? They both measure close to 10uf with my cheap meter.
yes those are fine

Spot on Pete.

Motnick: Check C43 and C44 on the meter as well.
 
Both C43 and C44 measure 1.5uf.

Although the service manual lists C43 and C44 as 10uf / 16v electrolytics, it looks like 1.5uf / 25v tantulums are actually installed in my unit.

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I reinstalled C43 and C44, and I replaced C45 and C46 with the 10uf / 50v caps that I had on hand. The volume in both channels now seems to be the same!

I’d like to reinstall F5 next but unfortunetly I didn’t mark F5 before I removed it the other day . It looks like F5 can be installed two different ways. Does it matter which way I reinstall it?
 
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look for clues as to the original lid alignment and your disassembly.

I'm punchy but it LOOKS like an ohmmeter test between pins might tag the difference.

worst comes to worst, put it in, test things, then try it the other way and see if there's a difference.
resistor isolated as it is, there wouldn't be any damage, just maybe a discernible difference that doesn't need a scope to spot.

There's a lesson or two in here but I'm too dead to type more.
 
A closer examination of F5 does not reveal any obvious differences that I can see. I think that this filter (ATF-042) can be installed either way. I flipped a coin and took a chance and installed it back onto the board. FM stereo is working perfectly now. Thank you guys for all of your help with this. I feel like I really learned a lot on my first tuner board adventure!

What does the C45 and C46 part of the circuit actually do anyway?

Should I replace anything else on the tuner board?

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c45 46 look like decoupling to me if i am looking at it correctly . if they were being like resistors in any way it would be like a vol control and lower the power of the signal taking it towards ground . i can only guess what might happen if they went open circuit .
mark might put me right on this and have a better explanation . i dont do tuner circuits as it happens .
p.s well done am glad its now sorted .
 
C45 and C46 part of the circuit is called for by the manufacturer of the HA1196 stereo decoder chip. Their need is for something inside of the chip. I can guess BUT I chose not to.

ha1196_circuit.png
 
With the power amp rebuilt and the FM stereo issue ironed out I thought that I was ready to move onto the full recap, but unfortunetly I have noticed another issue.

The low cut filter does not seem to be working. I’ve already cleaned the switches and pots on the entire unit. All of the other tone controls work fine including the high cut filter. Flipping the low cut filter seems to have no effect on either channel.

Looking at the schematic I don’t really see anything that would cause it to not function on both channels like what I am experiencing here. Maybe the low cut filter is so suttle that I can’t notice it?
 
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Look at the circuit - it is either a 0.22uf cap in a coupling mode and 47k to ground, or the switch puts a short circuit across the cap - check that electrically, both short and 47k. High resistance can defeat either.
It is a CSZA cap which is tantalum, which can short - but BOTH of them at the same time??
First be sure the switch IS shorting across the cap, and that something else isn't as badly restricted on tonality due to age and dried out coupling caps that have lost bass response..
 
I made some measurements from the AWG-039 board. Measuring from pin 1 to pin 5, and also from pin 3 to pin 7 shows 0 resistance across the low cut switch when the low cut filter is turned Off (all other Tone controls turned Off).

I also moved the low cut switch to On and measured from the same pins as above, but used my capacitor tester. I’m not sure how valid this measurement is, but both channels read .22uf which is what the manaual says C25 and C26 should be.

I also measured R33 and R34 in circuit with the low cut switch Off. Both measure very close to 47k ohms.

If I’m understanding the circuit correctly then I think that this testing is showing everything is functioning correctly. Perhaps like Mark mentioned above, the overall condition of the unit is such that the low cut filter has no effect?

Unless you guys think that I should check anything else first, it seems like the best thing for me to do is move onto the full recap of the unit?
 
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I would like to move on to the power supply next. My PS is AWR-101-C. I can see that someone has worked on this board before. C14, C16, C18, C19, and C21 have all been replaced with 47uF/63V replacements. C23 has a 100uF/63V replacement installed. Q5 has been replaced with NTE289. Q8 and Q9 have NTE152 installed.

I plan to replace all of these components with the suggested Mouser replacements, but I am unsure on how to handle the capacitors that have been replaced. It looks like the previous tech installed a 47uF/63V anywhere that he found a 47uF, no matter the voltage of the original cap. Should I use the suggested replacements or replace with the same voltage values that are installed currently? I know the correct method is to replace with the same values as originally installed, but in this instance I don't know what was installed originally.

C14 really confuses me. The manual lists C14 as 220uF/10v. I was shocked to find a 47uF/63V replacement, but then I found another thread here on the forum that mentions the AWR-101-C revision used a 47uF/25V originally for C14.

http://audiokarma.org/forums/index.php?threads/sx-950-restore-awr-101c.677939/

C12 has what I believe to be an original cap of 2200uF/35V. The manual lists C12 as 1000uF/35V.

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Replace with whats in there.

Thanks Zebulon!

How does this list look based on what's in my actual PS board?


Power Supply Board: (AWR-101-C)

C10: 470uF 80v 647-UHE2A471MHD 470uF 100v
C11: 470uF 80v 647-UHE2A471MHD 470uF 100v
C12: 2200uF 35v 647-UPW1H222MHD 2200uF 50v
C13: 1000uF 25v CEA: 647-UPW1V102MHD 1000uF 35v
C14: 47uF 63v (found) 647-UPW1J470MPD 47uF 63v
C15: 470uF 63v CEA: 647-UPW2A471MHD 470uF 100v
C16: 47uF 63v (found) 647-UPW1J470MPD 47uF 63v
C18: 47uF 63v (found) 647-UPW1J470MPD 47uF 63v
C19: 47uF 63v (found) 647-UPW1J470MPD 47uF 63v
C20: 100uF 63v CEA: 647-UPW2A101MHD 100uF 100v
C21: 47uF 63v (found) 647-UPW1J470MPD 47uF 63v
C23: 100uF 63v (found) 647-UPW1J101MPD6 100uF 63v

Q1: 2SD313: 863-MJE15032G
Q2: 2SB507: 863-MJE15033G
Q3: 2SC1318: 512-KSC2383YTA
Q4: 2SA720: 512-KSA1013YBU
Q5: NTE289 (found): 512-KSC2690AYSTU
Q6: 2SA720: 512-KSA1013YBU
Q7: 2SC1318: 512-KSC2383YTA
Q8: NTE152 (found): 863-MJE15032G
Q9: NTE152 (found): 863-MJE15032G
Q10: 2SC869: 512-KSC2383YTA

Should I replace the diodes?
 
While I am on BOM, here is the rest of my list. I'd like to order the remaining pieces all at once if I can. I am looking forward to finishing this unit up.

Please let me know what you guys think.


Equalizer Amp Assembly (AWF-011-B)
AWF-011: C1: 1uF 25v CSSA: 505-MKS21.0/63/5 1uF 63v
AWF-011: C2: 1uF 25v CSSA: 505-MKS21.0/63/5 1uF 63v
AWF-011: C7: 330uF 6.8v CEA: 667-EEU-FM1C331 330uF 16v
AWF-011: C8: 330uF 6.8v CEA: 667-EEU-FM1C331 330uF 16v
AWF-011: C11: 3.3uF 25v CEANL: 647-UKL1H3R3KDDANA 3.3uF 50v
AWF-011: C12: 3.3uF 25v CEANL: 647-UKL1H3R3KDDANA 3.3uF 50v
AWF-011: C17 100uF 35v CEA: 667-EEU-FM1H101 100uF 50v
AWF-011: C18 220uF 25v CEA: 667-EEU-FM1V221 220uF 35v

AWF-011: Q1: 2SA725: 512-KSA992FBU
AWF-011: Q2: 2SA725: 512-KSA992FBU
AWF-011: Q3: 2SC1313: 512-KSC1845FTA
AWF-011: Q4: 2SC1313: 512-KSC1845FTA
AWF-011: Q5: 2SC1313: 512-KSC1845FTA
AWF-011: Q6: 2SC1313: 512-KSC1845FTA

If the B version:

AWF-011: C??: 100uF 6.3v CEA: 667-EEU-FM1A101 100uF 10v
AWF-011: C??: 100uF 6.3v CEA: 667-EEU-FM1A101 100uF 10v

Switch Assembly Board (AWS-094)
AWS-094: C1: 220uF 6.8v CEA: 667-EEU-FM1V221 220uF 35v

Flat Amp Board (AWG-038)
AWG-038: C1: 2.2uF 50v CEANL(NL): 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-038: C2: 2.2uF 50v CEANL(NL): 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-038: C5: 4.7uF 50v CEANL(NL): 647-UKL1J4R7MDD 4.7uF 63v
AWG-038: C6: 4.7uF 50v CEANL(NL): 647-UKL1J4R7MDD 4.7uF 63v
AWG-038: C13: 220uF 35v CEA: 667-EEU-FM1V221 220uF 35v
AWG-038: C14: 220uF 35v CEA: 667-EEU-FM1V221 220uF 35v
AWG-038: C17: 10uF 25v CSZA: 647-UKL1E100MDDANA10uF 25v
AWG-038: C18: 10uF 25v CSZA: 647-UKL1E100MDDANA10uF 25v
AWG-038: C23: 4.7uF 50v CEANL(NL): 647-UKL1J4R7MDD 4.7uF 63v
AWG-038: C24: 4.7uF 50v CEANL(NL): 647-UKL1J4R7MDD 4.7uF 63v
AWG-038: C25: 100uF 10v CEANL(NL): 647-UKL1A101KEDANA 100uF 10v
AWG-038: C26: 100uF 10v CEANL(NL): 647-UKL1A101KEDANA 100uF 10v
AWG-038: C27: 100uF 50v CEA: 667-EEU-FM1H101 100uF 50v

AWG-038: Q1: 2SC1885: 512-KSC2383YTA
AWG-038: Q2: 2SC1885: 512-KSC2383YTA
AWG-038: Q5: 2SA725: 512-KSA992FBU
AWG-038: Q6: 2SA725: 512-KSA992FBU

Tone Amp Board (AWG-039-C)
AWG-039: C13: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-039: C14: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-039: C15: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-039: C16: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-039: C19: 100uF 10v CEANL(NL): 647-UKL1A101KEDANA 100uF 10v
AWG-039: C20: 100uF 10v CEANL(NL): 647-UKL1A101KEDANA 100uF 10v
AWG-039: C21: 47uF 35v CEA: 667-EEU-FC1V470 47uF 35v
AWG-039: C22: 47uF 35v CEA: 667-EEU-FC1V470 47uF 35v
AWG-039: C23: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-039: C24: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-039: C25: .22uF 35v CSZA: 505-MKS20.22/63/5 .22uF 63v
AWG-039: C26: .22uF 35v CSZA: 505-MKS20.22/63/5 .22uF 63v
AWG-039: C29: 10uF 25v CSZA: 647-UKL1E100MDDANA10uF 25v
AWG-039: C30: 10uF 25v CSZA: 647-UKL1E100MDDANA10uF 25v

AWG-039: Q1: 2SC1312: 512-KSC1845FTA
AWG-039: Q2: 2SC1312: 512-KSC1845FTA

Protection Circuit Assembly (AWM-062)
AWM-062: C1: .22uF 10v CSSA: 505-MKS20.22/63/5 .22uF 63v
AWM-062: C2: .22uF 10v CSSA: 505-MKS20.22/63/5 .22uF 63v
AWM-062: C3: 330uF 6.8v CEA: 647-UPW1A331MPD 330uF 10v
AWM-062: C4: 330uF 6.8v CEA: 647-UPW1A331MPD 330uF 10v
AWM-062: C5: 4.7uF 25v CEA: 647-UPW1V4R7MDD 4.7uF 35v
AWM-062: C6: 100uF 16v CEA: 647-UPW1V101MPD 100uF 35v

AWR-062: Q1: 2SC869: 512-KSC1845FTA
AWR-062: Q2: 2SC869: 512-KSC1845FTA
AWR-062: Q6: 2SC945: 512-KSC2383YTA
AWR-062: Q7: 2SC1318: 512-KSC2690AYS

1N4004 fly back diode is added between pins 9 (anode) and 10 (cathode)

Filter Caps
C1: 22,000uf 63V: 661-E36D800N223MC92M 22,000uf 80V (50.8mm x 92mm)
C2: 22,000uf 63V: 661-E36D800N223MC92M 22,000uf 80V (50.8mm x 92mm)

Bleeder Resistors
R1: 2.7K ohms 2W Metal Oxide: 660-MOS3CT631R272J 2.7K ohms 3W
R2: 2.7K ohms 2W Metal Oxide: 660-MOS3CT631R272J 2.7K ohms 3W

Protection Relay
653-LY2F-DC24
 
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I finished up replacing the caps and transistors on the power supply board tonight. Should I replace any of the diodes on this board?

Please let me know what you guys think of these PS voltages (house power). Pin 2 & 3 seem a bit high to me.

Pin 2 (5.4v) 6.4v
Pin 3 (5.4v) 6.4v
Pin 4 (13.9v) 13.6v
Pin 5 (13.9v) 13.6v
Pin 6 (51.5v) 51.0v
Pin 7 (51.5v) 51.0v
Pin 8 (36.5v) 36.5v
Pin 9 (36.5v) 36.5v
Pin 10 (36.5v) 36.5v
Pin 11 (28.0v) 28.2v
Pin 13 (-13.5v) -13.2v
Pin 14 (-51.5v) -50.4v
Pin 15 (-19.0v) -18.5v

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