Pioneer SX-636 Phono stage problem

[Omegaman]

Request for assistance

I have a Pioneer SX-636, everything works fine except the Phono input

One channel is distorted.

I have done all the normal magic to exclude switches, pots, connections and whatnot as the easy fix. De-Oxited all

Now I believe it is a failed component like a transistor

So instead of spending $100 bucks at the shop, I thought I would ask here

I got it open on the bench here

What do I look for?

Thanks for any assistance

 

[tsd71]

Clean the phono jacks in the back with a pipe cleaner and Deoxit first.

 

[Omegaman]

Clean the phono jacks in the back with a pipe cleaner and Deoxit first.

Thanks but I did all that. I have eliminated all the easy fixes

 

[larryderouin]

Don; Probably best just to do a recap and replace the 4 2sc1344's. Here's the list for the AWF-014 Equalizer board (phono preamp board).

eq amp
awf-014 c1 3.3 10 csza 3.3 50 647-UKL1H3R3MDDANA
awf-014 c2 3.3 10 csza 3.3 50 647-UKL1H3R3MDDANA
awf-014 c3 0.47 50 cea 0.47 100 667-ECQ-E1474KF
awf-014 c4 0.47 50 cea 0.47 100 667-ECQ-E1474KF
awf-014 c5 100 35 cea 100 35 647-UPW1V101MPD1TD
awf-014 c6 100 35 cea 100 35 647-UPW1V101MPD1TD
awf-014 c11 22 10 cea 22 50 647-UPW1H220MDD
awf-014 c12 22 10 cea 22 50 647-UPW1H220MDD
awf-014 c13 0.47 35 csza 0.47 100 667-ECQ-E1474KF
awf-014 c14 0.47 35 csza 0.47 100 667-ECQ-E1474KF
awf-014 q1 2sc1344 x x x x 512-KSC1845FTA
awf-014 q2 2sc1344 x x x x 512-KSC1845FTA
awf-014 q3 2sc1344 x x x x 512-KSC1845FTA
awf-014 q4 2sc1344 x x x x 512-KSC1845FTA


Also you might want to replace all of the 2sa725 and 2sa726 with KSA992's where-ever you find them. And the #1 suspect on the top ten wanted list is the 2sc1451 on the amps. Replace with ksc3503.

Here's the whole kit and kaboodle in case you want to do the whole 636.
eq amp
awf-014 c1 3.3 10 csza 3.3 50 647-UKL1H3R3MDDANA
awf-014 c2 3.3 10 csza 3.3 50 647-UKL1H3R3MDDANA
awf-014 c3 0.47 50 cea 0.47 100 667-ECQ-E1474KF
awf-014 c4 0.47 50 cea 0.47 100 667-ECQ-E1474KF
awf-014 c5 100 35 cea 100 35 647-UPW1V101MPD1TD
awf-014 c6 100 35 cea 100 35 647-UPW1V101MPD1TD
awf-014 c11 22 10 cea 22 50 647-UPW1H220MDD
awf-014 c12 22 10 cea 22 50 647-UPW1H220MDD
awf-014 c13 0.47 35 csza 0.47 100 667-ECQ-E1474KF
awf-014 c14 0.47 35 csza 0.47 100 667-ECQ-E1474KF
awf-014 q1 2sc1344 x x x x 512-KSC1845FTA
awf-014 q2 2sc1344 x x x x 512-KSC1845FTA
awf-014 q3 2sc1344 x x x x 512-KSC1845FTA
awf-014 q4 2sc1344 x x x x 512-KSC1845FTA

af amp
awk-035 c5 1 25 csza 1 50 647-UKL1H010KDDANA
awk-035 c6 1 25 csza 1 50 647-UKL1H010KDDANA
awk-035 c9 100 16 cea 100 35 647-UPW1V101MPD1TD
awk-035 c10 100 16 cea 100 35 647-UPW1V101MPD1TD
awk-035 c13 4.7 25 cea 4.7 50 647-UPW1H4R7MDD
awk-035 c14 4.7 25 cea 4.7 50 647-UPW1H4R7MDD
awk-035 c21 4.7 25 cea 4.7 50 647-UPW1H4R7MDD
awk-035 c22 4.7 25 cea 4.7 50 647-UPW1H4R7MDD
awk-035 c23 4.7 25 cea 4.7 50 647-UPW1H4R7MDD
awk-035 c24 4.7 25 cea 4.7 50 647-UPW1H4R7MDD
awk-035 c25 2.2 25 cssa 2.2 50 647-UKL1H2R2KDDANA
awk-035 c26 2.2 25 cssa 2.2 50 647-UKL1H2R2KDDANA
awk-035 c27 47 10 cea 47 35 647-UPW1V470MED1TD
awk-035 c28 47 10 cea 47 35 647-UPW1V470MED1TD
awk-035 c31 100 35 cea 100 35 647-UPW1V101MPD1TD
awk-035 q1 2sa726 x x x x 512-KSA992FBU
awk-035 q2 2sa726 x x x x 512-KSA992FBU
awk-035 q3 2sc1344 x x x x 512-KSC1845FTA
awk-035 q4 2sc1344 x x x x 512-KSC1845FTA
awk-035 q5 2sc1344 x x x x 512-KSC1845FTA
awk-035 q6 2sc1344 x x x x 512-KSC1845FTA

power amp
awh-034 c1 0.33 25 cssa 0.33 50 598-DSF050J334
awh-034 c2 0.33 25 cssa 0.33 50 598-DSF050J334
awh-034 c7 220 6 cea 220 10 647-UPW1A221MED
awh-034 c8 220 6 cea 220 10 647-UPW1A221MED
awh-034 c9 47 35 cea 47 35 647-UPW1V470MED1TD
awh-034 c10 47 35 cea 47 35 647-UPW1V470MED1TD
awh-034 q1 2sa726 x x x x 512-KSA992FBU
awh-034 q2 2sa726 x x x x 512-KSA992FBU
awh-034 q3 2sa726 x x x x 512-KSA992FBU
awh-034 q4 2sa726 x x x x 512-KSA992FBU
awh-034 q5 2sc1451 x x x x 512-KSC3503dstu
awh-034 q6 2sc1451 x x x x 512-KSC3503dstu

power supply
awr-060/61 c6 470 50 cea 470 50 647-UPW1H471MHD
awr-060/61 c7 220 50 cea 220 50 647-UPW1H221MPD
awr-060/61 c8 220 50 cea 220 50 647-UPW1H221MPD
awr-060/61 c9 100 50 cea 100 50 647-UPW1j101MPD
awr-060/61 c11 100 16 cea 100 35 647-UPW1V101MPD1TD
awr-060/61 c12 220 16 cea 220 25 647-UPW1E221MPD
awr-060/61 c13 10 35 cea 10 50 647-UPW1H100MDD
awr-060/61 c14 220 50 cea 220 50 647-UPW1H221MPD
awr-060/61 c16 100 16 cea 100 35 647-UPW1V101MPD1TD
awr-060/61 q1 2sd234 x x x x 512-KSC2073TU
awr-060/61 q2 2sc945 x x x x 512-KSC2383Yta
awr-060/61 q3 2sd313 x x x x 512-KSC2073TU
awr-060/61 d8 wz-140 x x x x 512-1N5244B


misc c3 6800 35
misc c4 6800 35
misc c8 100 6 cea 100 35 647-UPW1V101MPD1TD



tuner tuner
awe-046 c18 4.7 25
awe-046 c20 10 16
awe-046 c21 0.47 50
awe-046 c25 1 50
awe-046 c28 100 16
awe-046 c32 4.7 25
awe-046 c33 47 6
awe-046 c36 0.1 25
awe-046 c39 10 16
awe-046 c44 10 16
awe-046 c48 0.33 10
awe-046 c49 1 10
awe-046 c50 0.47 10
awe-046 c59 0.33 25
awe-046 c60 0.33 25
awe-046 c61 220 16


BOM list :
647-UKL1H3R3MDDANA
647-UKL1H3R3MDDANA
667-ECQ-E1474KF
667-ECQ-E1474KF
647-UPW1V101MPD1TD
647-UPW1V101MPD1TD
647-UPW1H220MDD
647-UPW1H220MDD
667-ECQ-E1474KF
667-ECQ-E1474KF
512-KSC1845FTA
512-KSC1845FTA
512-KSC1845FTA
512-KSC1845FTA


647-UKL1H010KDDANA
647-UKL1H010KDDANA
647-UPW1V101MPD1TD
647-UPW1V101MPD1TD
647-UPW1H4R7MDD
647-UPW1H4R7MDD
647-UPW1H4R7MDD
647-UPW1H4R7MDD
647-UPW1H4R7MDD
647-UPW1H4R7MDD
647-UKL1H2R2KDDANA
647-UKL1H2R2KDDANA
647-UPW1V470MED1TD
647-UPW1V470MED1TD
647-UPW1V101MPD1TD
512-KSA992FBU
512-KSA992FBU
512-KSC1845FTA
512-KSC1845FTA
512-KSC1845FTA
512-KSC1845FTA


598-DSF050J334
598-DSF050J334
647-UPW1A221MED
647-UPW1A221MED
647-UPW1V470MED1TD
647-UPW1V470MED1TD
512-KSA992FBU
512-KSA992FBU
512-KSA992FBU
512-KSA992FBU
512-KSC3503dstu
512-KSC3503dstu


647-UPW1H471MHD
647-UPW1H221MPD
647-UPW1H221MPD
647-UPW1j101MPD
647-UPW1V101MPD1TD
647-UPW1E221MPD
647-UPW1H100MDD
647-UPW1H221MPD
647-UPW1V101MPD1TD
512-KSC2073TU
512-KSC2383Yta
512-KSC2073TU
512-1N5244B




647-UPW1V101MPD1TD

 

[Omegaman]

Now THAT is the answer I was hoping for, Thanks LD

 

[niles300z]

So, without a schematic and knowledge i am stuck. Same problem here. Phono has static with no input. My question is omega, did you end up doing the whole eq board, did it help, or did you do part of it to narrow down what may have been the failed parts. Im not up to redoing the whole board. By the way, is the eq board the one closest to the back with the tuner or the one more up front closer to the transistors? Thanks.
Niles

 

[larryderouin]

Niles. Look in the Service manual. It's on the board drawings on pages 20 or 22 IIRC. Also check the other 636 thread where you posted. I posted some stuff up on that one for you and the other guys. The phono goes thru the Mic input, so if you have Earphones with a 1/4" plug, DeOxit the plug and the jack and "ream" the hole with the Plug about 5 minutes worth. BRISKLY!


SX-636 manuals and brochures http://www.kallhovde.com/pioneer/Pioneer/Main%20scan%20page.html Scroll down to SX-636 Bookmark the link in case of more units in your stash.