How to get at the pots on a Pioneer SX1280 Please?

postman56

postman56

Active Member
I had a quick look inside of my lovely Pioneer SX-1280 to see that the pots are enclosed in a housing so it doesn't appear like it's going to be a simple shot of Deoxit into them.
Any help and suggestions would be appreciated, for I've got one that's acting up.
Appreciated
Ken
 
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You will need to pull the board and flip back to access it properly. I just cleaned an SX-1980 and the only truly closed pot is the volume pot. The Tone pots have ample access drone side ports and bottom edges. Even the Vol pot had very small openings along front corners where cover plate meets housing. I put a couple good shots of FaderLube in those. I didn’t feel comfortable attempting to pull the plate off to look inside for fear might not be able to reassemble or losing some small piece. hopefully someone will add their experience with that closed Volume pot on these models.
 
I'm sorry I'm not sure of "pull the board, is that easily accessible, from the top bottom?
Your help is appreciated
 
postman56 said:
I'm sorry I'm not sure of "pull the board, is that easily accessible, from the top bottom?
Your help is appreciated
Click to expand...
Agree with rcs16, a bit more detail on the exact problem/symptoms or pot / switch you are having issues with.

All pots and switches are mounted on several circuit boards behind the front panel below the tuner dial. Typically accessible from bottom. Requires removing all knobs, switch covers, front face plate, lock nuts w/washers holding pots to front panel. Then the unit can be set on it's topside and you can carefully work the board out of the front panel and flip it over to access the pots. Just be careful about flexing the wires too much so not to break any. Slow and steady is the way. If you have no experience you may want to have a qualified tech do this depending on your level of confidence.

Take of Pictures before each step. to aid in reassembly. I recommend having a look at the assembly drawings in the service manual you should download from hifiengine.
 
I'm having a bit of distortion/cutting out occasionally and it seems to be remedied if I toggle the front loudness switch or the two tape monitor switches.
Much Appreciated
 

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The switches are old, silver plated and tarnish with black oxide, they need a good cleaning, this is just a band aid fix, buys you some time or worse, need to be taken all apart and done properly, not for the faint or heart.
 
rcs16 said:
<<snip>> not for the faint or heart.
Click to expand...

This is true. I disassembled some, takes lots of time and patience, good eyes and good dexterity. It is much easier to ruin them than to get them back together properly and you need to be very very careful.
 
Syrup of IPECAC works wonders. That 1280 puked it's guts out and then some.....:music::music::music::music:
 
hertzdonut said:
C'mon guys, it's not that scary. Well, maybe a little. :eek: (Photo of my 1280 when I was working on it a couple of years ago.)/QUOTE]
Click to expand...

Lol, was thinking same. Here is pic of SX-1980 I just cleaned all controls. Did not disassemble switches so will probably be back again in near future. Owner was OK with that trying to keep cost at minimum. Problem on this was the Phono switches. Not the big lever ones. And hadn't even pulled those push switch boards yet.
00F6AFDB-EF95-4C09-8BB0-1C4FC4F17368.jpeg
 
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The pot for the 1280 may be able to be reached from the back. On my SA 9500II I was able to loosen the four screws on the back of pot just enough to be able to squeeze some Deoxit 100% followed by Caig Fader and then Caig Shield into the cracks. That was over 10 years ago and it is still fine today. You do not want to disassemble those units, very complicated.
 
Your photo is a sx-1250 - maybe you just grabbed a stock photo from Google?

As others have said you need to desolder the switch and take it apart. The first time it is hard, after that gets easy. I suggest buying a replacement on eBay and clean that one. That way once the old switch is out, the new one goes right in.

Here's a before and after of a dirty switch

20190810_142900.jpg 20190810_143219.jpg

The 1280's wires that connect each board break pretty darn easy. Be prepared to troublesboot!

Also, with such a beautiful receiver such at the 1280, I would get a dim bulb tester which to me is required before powering up any stereo after service, big or small.
 
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