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Help with Pioneer SX727

T

tony7025

AK novice
Hi,
I am a complete novice as far as restoring an amp is concerned. I have a pioneer sx727 which I found at a car boot!!
I have cleaned the switches with switch cleaner, gave it a fresh coat of varnish and it looked like new. But!!! :tears: when I wired it up I found that the right channel is noticeably quieter than the left and when the volume is up the sound cuts in and out.
Anyway to cut to the chase is it worth me trying to recap it, as I said "complete novice!":confused:
Any help would be greatly appreciated i.e. what to buy where to buy and how to do it???? sorry I know its a big ask but any guidance would be appreciated. :ntwrthy:
:thmbsp:

Oh sorry forgot to mention that the FM bulb is out too!!
 
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Get some DeOxit D-5 and Faderlube F-5. They have the "cojones" to cut thru the sulfur deposits from the air that corrodes the contacts on the switches. Regular "switch cleaner doesn't. DO ALL the switches, pots (volume, balance, etc) and the RCA plugs in the rear. (RCA's get DeOxit on a pipe cleaner, then scrub in and out). 1st thing done is to clean all the contact points as the signal goes thru ALL of them at one point or another. Most troublesome are the TAPE MONITOR, and FILTER SWITCHES. Once they are clean and scratch free (sound wise) and you still have a problem, then we'll move on to the "hard Stuff".

Also read this thread to help understand what I just told you. :D "The Idiot's Guide to using De-Oxit.....Re-Visited"

BTW...Welcome to AUDIOKARMA. There are some threads on the SX-727 here that should shed some light on the subject.

SERVICE MANUAL is MANDATORY!!! Get it HERE Scroll down to SX-727 and download all 7 files. 2 are reviews, Service Manual, Schematic, Owners manual, Protection unit Supplement, Brochure.

Add a city and state to your profile. It'll help with other members that might have a similar unit if you need personal help.

Larry
 
My guess is on the other side of a large body of salty water from us....

Don't forget to do the jumpers between the PRE-OUT and MAIN-IN jacks.

Then use headphones once to check the balance, WITHOUT any other speakers turned on.
 
i am also guessing he is on the same island as i am .. if so deoxit isn't so easy to get here . servisol super 10 however is and it does the job fine .. its available at maplin for loads a money . or much cheaper from that ebay or an electronics supplier .
 
I wondered about that "CAR BOOT" later. Some kind of flea market, out of the trunk(boot) of a car???
 
Hi Guys,
thanks for the advice I will give it a go today.
a car boot is basically a large field and people drive in, in their cars and pitch a table to sell things from.
I am as you say from over the pond! There doesn't seem to be any sites like (as good as) this in the UK.
I am very grateful for your help and links. My background is military, and now computing so as far as electronics is concerned 'a novice'.
I will try to follow your instructions and repost with how I get on.

Thanks
 
tony; Get with Petehall over there (PM him). He might be able (time and location constraints) to "look over your shoulder" as it were and give you some off the net or in person advice.

Larry
 
Thanks Larry, will do.
I have cleaned and lubed everything to no avail? the right channel is still noticeably quieter than the left and still crackles.
I have crossed the channels from the pre to the main amp and this transfers the problem to the other side?? so not the RCA sockets, I don't think????
Any ideas what I should try next???
Heeeeeelp!! lol
 
You have isolated the problem to the pre-amp. You don't mention whether it occurs on all sources (phono, fm, aux, tape). If so it is in a part of the circuit that is before the power amps, but common to all sources. Otherwise it is isolated to a particular spot (phono board etc.). Having a look at the service manual might help narrow it down. Sometimes there will be a "block diagram" (like a flow chart) that shows the signal path. You've got a couple of heavy-hitters" ( Markthefixer and Larryderouin) to help isolate the problem. For what it's worth- I would troubleshoot before re-capping if possible; re-capping is great (I've done several) but it doesn't necessarily address the problem. I say this because I've re-capped a couple of iffy receivers WITHOUT tracking down the problem- hoping it would go away, and it was still there. Getting into the transistors and stuff may seem daunting,but it's less frustrating (imo) than doing a full re-cap and then having to go BACK into the unit after. Good luck!
 
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Basically, this is the part list , the bolded and underlined are the new parts number which you need to copy and past in Mouser.com

General c1 6800uF 50v CEW 647-UVZ1J682MRD 6800 63 $3.72
General c2 6800uF 50v CEW 647-UVZ1J682MRD 6800 63 $3.72
General c3 1000uF 63v CEW 647-UPW2A102MHD 1000 100 $2.06
General c6 220uF 10v CEA 647-UPW1A221MED 220 10 $0.18
General c7 330uF 16v CEA 647-UPW1E331MPD6 330 25 $0.28
General ? 220uF 50v CEA 647-UPW1J221MPD6 220 63 $0.62

phono /head amp
W21-002 c1 22uF 16v CEA 647-UPW1V220MDD 22 35 $0.15
W21-002 c2 22uF 16v CEA 647-UPW1V220MDD 22 35 $0.15
W21-002 c3 4.7uF 25v CEA 647-UPW1H4R7MDD 4.7 50 $0.12
W21-002 c4 4.7uF 25v CEA 647-UPW1H4R7MDD 4.7 50 $0.12
W21-002 c5 10uF 25v CEA 647-UPW1H100MDD 10 50 $0.12
W21-002 c6 10uF 25v CEA 647-UPW1H100MDD 10 50 $0.12
W21-002 c15 220uF 35v CEA 647-UPW1V221MPD 220 35 $0.22

tuner
AWE-015 c2 .47uF 50v CEA 598-DSF050J474 0.47 50 $0.29
AWE-015 c23 4.7uF 25v CEA 647-UPW1H4R7MDD 4.7 50 $0.12
AWE-015 c27 1uF 50v CEA 647-UPW1H010MDD 1 50 $0.12
AWE-015 c29 4.7uF 25v CEA 647-UPW1H4R7MDD 4.7 50 $0.12
AWE-015 c30 1uF 50v CEA 647-UPW1H010MDD 1 50 $0.12
AWE-015 c33 100uF 16v CEA 647-UPW1V101MPD 100 35 $0.26
AWE-015 c36 10uF 16v CEA 647-UPW1H100MDD 10 50 $0.12
AWE-015 c38 .47uF 50v CEA 598-DSF050J474 0.47 50 $0.29
AWE-015 c45 10uF 16v CEA 647-UPW1H100MDD 10 50 $0.12
AWE-015 c53 .47uF 25v CSSA 598-DSF050J474 0.47 50 $0.29
AWE-015 c54 4.7uF 25v CEA 647-UPW1H4R7MDD 4.7 50 $0.12
AWE-015 c55 3.3uF 16v CSSA 647-UKL1H3R3KDDANA 3.3 50 $0.20
AWE-015 c57 3.3uF 16v CSSA 647-UKL1H3R3KDDANA 3.3 50 $0.20
AWE-015 c58 1uF 50v CEA 647-UPW1H010MDD 1 50 $0.12
AWE-015 c61 .47uF 50v CEA 598-DSF050J474 0.47 50 $0.29
AWE-015 c65 100uF 16v CEA 647-UPW1V101MPD 100 35 $0.26
AWE-015 c66 2.2uF 16v CSSA 647-UKL1H2R2MDDANA 2.2 50 $0.20
AWE-015 c67 2.2uF 16v CSSA 647-UKL1H2R2MDDANA 2.2 50 $0.20
AWE-015 c73 47uF 16v CEA 647-UPW1E470MDD 47 25 $0.19

af amp
AWK-010 c7 47uF 50v CEA 647-UPW1H470MED 47 50 $0.22
AWK-010 c8 47uF 50v CEA 647-UPW1H470MED 47 50 $0.22
AWK-010 c13 2.2uF 25v CSSA 647-UKL1H2R2MDDANA 2.2 50 $0.20
AWK-010 c14 2.2uF 25v CSSA 647-UKL1H2R2MDDANA 2.2 50 $0.20
AWK-010 c15 47uF 10v CEA 647-UPW1E470MDD 47 25 $0.19
AWK-010 c16 47uF 10v CEA 647-UPW1E470MDD 47 25 $0.19
AWK-010 c21 2.2uF 25v CSSA 647-UKL1H2R2MDDANA 2.2 50 $0.20
AWK-010 c22 2.2uF 25v CSSA 647-UKL1H2R2MDDANA 2.2 50 $0.20
AWK-010 c27 2.2uF 25v CSSA 647-UKL1H2R2MDDANA 2.2 50 $0.20
AWK-010 c28 2.2uF 25v CSSA 647-UKL1H2R2MDDANA 2.2 50 $0.20
AWK-010 c29 100uF 6.3v CEA 647-UPW1A101MDD 100 10 $0.14
AWK-010 c30 100uF 6.3v CEA 647-UPW1A101MDD 100 10 $0.14
AWK-010 c31 47uF 50v CEA 647-UPW1H470MED 47 50 $0.22
AWK-010 c32 47uF 50v CEA 647-UPW1H470MED 47 50 $0.22

power amp
AWH-011 c7 22uF 10v CEA 647-UPW1V220MDD 22 35 $0.15
AWH-011 c8 22uF 10v CEA 647-UPW1V220MDD 22 35 $0.15
AWH-011 c9 220uF 10v CEA 647-UPW1A221MED 220 10 $0.18
AWH-011 c10 220uF 10v CEA 647-UPW1A221MED 220 10 $0.18
AWH-011 c15 100uF 50v CEA 647-UPW1H101MPD 100 50 $0.22
AWH-011 c16 100uF 50v CEA 647-UPW1H101MPD 100 50 $0.22

protection
AWM-027 c3 470uf 6.3v CEA 647-UPW1C471MPD 470 16 $0.34
AWM-027 c4 470uf 6.3v CEA 647-UPW1C471MPD 470 16 $0.34
AWM-027 c5 100uF 16v CEA 647-UPW1V101MPD 100 35 $0.26
AWM-027 c6 4.7uF 50v CEA 647-UPW1H4R7MDD 4.7 50 $0.12

power supply
AWR-011 c6 100uF 50v CEA 647-UPW1H101MPD 100 50 $0.22
AWR-011 c7 100uF 50v CEA 647-UPW1H101MPD 100 50 $0.22
AWR-011 c9 220uF 35v CEA 647-UPW1V221MPD 220 35 $0.22
AWR-011 c10 220uF 16v CEA 647-UPW1V221MPD 220 35 $0.22
AWR-011 c11 220uF 16v CEA 647-UPW1V221MPD 220 35 $0.22
 
larryderouin said:
I wondered about that "CAR BOOT" later. Some kind of flea market, out of the trunk(boot) of a car???
Click to expand...

I remember back in the 70's you'd be able to drive through the Forest Preserves in the Chicago area and see cars with signs hanging from open trunk lids advertising the types of mind altering substances they had for sale. Ranging from ounces of 'Mexican' for $15 to 'Columbian Gold' for $35 and 'Panama Red' for $45.

I've heard these substances made music sound better whether from a live band or played on audio equipment.

See how I made my post audio equipment related?

This of course is what I heard...I can't substantiate whether it was true or not.
 
another round of cleaning is what i might try next . work each control and switch about 30 to 50 times .
and try other inputs .also try a different source and different rca leads .
if after this is done it is still playing up you will need to be delving further in .
i am rather too far away from you to nip round and and have a look with you . hyperion is closer to you than i am .
 
tony7025 said:
Thanks Larry, will do.
I have cleaned and lubed everything to no avail? the right channel is still noticeably quieter than the left and still crackles.
I have crossed the channels from the pre to the main amp and this transfers the problem to the other side?? so not the RCA sockets, I don't think????
Any ideas what I should try next???
Heeeeeelp!! lol
Click to expand...

It moved, thus identifying the preamp section as the problem.

see if the stereo/mono switch in (mono) evens it out.

also cut the filters in and out, (in stereo) and see if there's a difference.
same with "loudness" switch.

also does the volume control or balance control have any effect on the crackles?
 
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