I bought a second--hand stereo receiver on the internet (Technics SA-EX410) and I can't get a decent speaker connection, regardless of the speakers used. They're always cutting in and out as if the contact points are dirty. They might be fine for a day or two but eventually one or the other track goes AWOL and I have to jiggle the connections. I tried cleaning them with alcohol but makes no difference. The unit shows no external signs of abuse. It's a pity because it sounds great - when working.
Hello Johnsabljic :-)
Being an old stereo, the most probable cause are dirty contacts in all of your controls and switches - especially A-B speaker switches.
Remove all round plastic knobs from your volume, tone, balance (etc.) controls. (they should be pried off carefully with a flat blade screwdriver)
squirt a little contact cleaner (or WD40 if contact cleaner not available. I use a 50 - 50 % WD40 and rubbing alcohol solution in an old Visine container - but if you do this always label the container "Contact Cleaner" as you don't want someone to use it to clean their eyes and go blind)
Squirt about a half a teaspoon of contact cleaner around each rotary shaft where it enters into control surrounded by the nut.
Do this also with all on/off switches and sliding controls as well.
Manually turn all rotary controls back and forth so the solution will work itself in. Move all sliding controls back and forth also, and click all switches on and off as well.
I would let it sit for about an hour before you power it up.
I run into this alot when I refurbish old receivers and eight track players.
Good luck,
Fred
Not sure what you mean by decent spkr connection, if you mean its scratchy as far as the sound, I would say its your volume control that is dirty and needs a shot of electronic cleaner you need to remove cover and spray product inside the control and rotate as in vol up/down to clean the control
as for the A or B connections do you mean A & B as in left/right channel or is there connections for front and rear speaker connections i.e.( A=Frt and B=Rear)? and does it seem to be only the left or right side channel doing this? I might wonder if touching the connection may have a capacitive effect on the output I.C. or Transistor(s) whichever this particular unit uses, and if this unit uses a single I.C. for both left and right sound output the touching of the output spkr connection may stabilize the circuit temporarily....just an idea!
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Thanks, dmftrucker, but it doesn't appear to be a volume problem. The sound is great - when the speakers work. I've tried connecting them to the A connectors, the B connectors, one A and one B. It's all the same. They might be fine for a day or two but sooner or later, I will lose sound in one of the speakers. If I touch the connection it's ususally enough to bring it back - but only temporarily. It never results in a long-term connection.
The A and B are two separate sets of speaker connectors, each with its own Left and Right. Both left and right channels are affected and it seems random. The sound will be fine for maybe three days and then out of the blue, one or the other channel will go silent - unless you manipulate the connection in the back. It's as if the speaker wire becomes loosened - but that doesn't appear to be the problem. So it might be a transistor problem? Is that something a complete newbie like me could fix?
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