• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

SX-1280 pops in right channel

N

native

Member
After spraying the switches with deoxit, I was flipping the levers and pushing the buttons when I heard a pop. Now when I flrp the levers on the flat amp or turn the volume control I get a pop through the right speaker. I've replaced the 2 2sk117 and the the 2 725s with a992s. Still get the pops. I verified the +32 and -32 rails are good. Has anybody run into this before? Any help or suggestions would be greatly appreciated .
 
Register to hide this ad
what did you replace the 2sk117s with? 2sk117 is a fet and cannot be replaced with ksa992 , Post a picture of the flat amp, maybe a transistor is reversed in pins
 
I replaced the 2sk117s with new 2sk117s. i replaced the 2sa725s with a992s, and they are clocked correctly. The receiver had been playing pefectly for about 30 minutes. I had just sprayed out the contols with deoxit and was checking for switching noise when I heard the pop through the speaker and this issue started.
 
Just to be clear, the jfets and transistors were changed after this issue began because it sure sounds like a transistor pop. I've seen both k117s and 725s fail in other units.
 
native said:
Just to be clear, the jfets and transistors were changed after this issue began because it sure sounds like a transistor pop. I've seen both k117s and 725s fail in other units.
Click to expand...
there are a bunch of trouble maker transistors in the sx1280 all of which can pop or crackle. not sure it's your exact problem, it sounds like dc making it to a switch which could be a bad capacitor.

the deoxit saturated switch could now be magnifying the problem. those toggle switches are easy to take apart and clean. it takes longer to access them and remove them than it does to disassemble and clean them.

i would chase down all the known bad transistors first, replace them then if the problem persists, at least they are ruled out. they need to be replaced anyway so it is not a waste of time.
 
I think I've replaced them all now. The two k117 and 2 725 on the flat amp, the 4 1312 on the tone amp and one more on the function switch board. I think that is all in the preamp section. Ive isolated the amp section and its working perfectly. I've also recapped the flat amp. I'm thinking that because only the switches and volume control on the flat board make the pop, that it seems likely that it is something on the flat amp board.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom