Pioneer SX-525 Mic input problems

[daveyh]

I have a SX-525 that I need some help on. The wires on the mic input have all bee cut and I do not know where they go to hook them back up. Perhaps someone has a unit apart and can take a close-up pic of the mic input and post it for me so I can fix this unit. I have tried to find a wiring diagram or a service manual on this and can not locate one. I know it's not worth much but it is in MINT cosmetic condition and I really would like to fix it.

 

[Noodle]

This might help.

http://www.kallhovde.com/pioneer/sx-525-s.pdf

 

[daveyh]

Thank you. I have these but I didn't see where the mic input is located. I have seen wiring diagrams that trace down the wires and show where they attach. The input is a six prong plug. The wires are just hanging there. Maybe I am missing something??

 

[Artie]

Davey; This could be a little tricky, because the phono and mic both share the phono preamp. The phono jacks would be bypassed when you plug in a mic. Whomever disconnected the mic jack would also have had to hardwire the phono jacks. They may simply have shorted 3-4, and 5-6 together, or they may have run them direct to the S1 wafers 2, 3, and 4.

Also, the reason they probably did this to begin with was that few people use the mic function. That means that the electrical contacts of that mic jack, (that connect the phono jacks), would slowly oxidize and/or corrode over time. Its a safe bet that you'ld need to remove it and clean it up real good before trying to reuse it.

Then, you just carefully follow that diagram and hook each wire up, point-to-point, as it originally was. Definitely could be a pita, depending on how the original owner "modded" it.

 

[markthefixer]

Davey; This could be a little tricky, because the phono and mic both share the phono preamp. The phono jacks would be bypassed when you plug in a mic. Whomever disconnected the mic jack would also have had to hardwire the phono jacks. They may simply have shorted 3-4, and 5-6 together, or they may have run them direct to the S1 wafers 2, 3, and 4.

Also, the reason they probably did this to begin with was that few people use the mic function. That means that the electrical contacts of that mic jack, (that connect the phono jacks), would slowly oxidize and/or corrode over time. Its a safe bet that you'ld need to remove it and clean it up real good before trying to reuse it.

Then, you just carefully follow that diagram and hook each wire up, point-to-point, as it originally was. Definitely could be a pita, depending on how the original owner "modded" it.

GOOD analysis...

That mic jack when corroding would mess up the phono input, thus the "bypass" that routes the signals from the phono jack straight into the phono amplifier input.

Unless you want to use the mic input, my suggestion would be to leave it as found. It will be a constant maintenance headache.

If you were to find a better (commercial audio) jack with nickel or gold plating, then the problem evaporates, but those type of jacks may be rare. I HAVE seen 30 year old professional jacks that have needed NO cleaning!....

If you're really determined, I could, in the next week or two, pull the 525 that I THINK I have on the shelf and try to document that jack, but with the schematic and an ohmmeter you can reconstruct the original wiring. Is the 470k resistor / 0.0018uF capacitor combo still in place??

 

[Rockmore]

GOOD analysis...

That mic jack when corroding would mess up the phono input, thus the "bypass" that routes the signals from the phono jack straight into the phono amplifier input.

Unless you want to use the mic input, my suggestion would be to leave it as found. It will be a constant maintenance headache.

If you were to find a better (commercial audio) jack with nickel or gold plating, then the problem evaporates, but those type of jacks may be rare. I HAVE seen 30 year old professional jacks that have needed NO cleaning!....

If you're really determined, I could, in the next week or two, pull the 525 that I THINK I have on the shelf and try to document that jack, but with the schematic and an ohmmeter you can reconstruct the original wiring. Is the 470k resistor / 0.0018uF capacitor combo still in place??

I was going to say the same thing: ..."Unless you want to use the mic input, my suggestion would be to leave it as found. It will be a constant maintenance headache..."

If I had the time I would "document that jack" for you also Davey, but dont (have the time at the moment). Markthefixer is a better source anyway LOL!