[orthobiz]

My daughter's been using this wonderful little amp but recently it developed an intermittent right phono channel. I just "happen" to have a Pioneer SX-828 sitting around that she is now using BUT do I fix the Kenwood or throw it out? I have some rusty soldering skills, I own a multimeter and am of above-average intelligence. But I have never built or repaired a stereo. I'd probably send it out to be fixed. Unless I opened it up, took photos and had group guidance..........

Paul

[Russellc]

Fix!  If its intermittant, its likely a pot or cold solder joint.  I'm betting its a pot.
Get some Deoxit, spray (using the little red tube) into each pot and or switch on the front panel and turn them from lock to lock numerous times. Push switches off and on in the same fashion. Repeat and try it again.
If that doesnt do it, its a solder joint some where.

Assuming you know enough to at least not get electrocuted, inspect not plugged in for funny solder joints.  Then I would fire it up and figure out what part is causing the intermittent problem and reflow its solder joints.  While usually a pot, (especially if the cutting out occurs while twiddling the pot) I have found the same thing with loose parts on boards to cold solder joints, where the intermittent nature is set off more from the unit being thumped instead of pot twiddling.

Inquire of "Echowars" over on Audiokarma.org in the vintage solid state forum. This era of stuff is his specialty, and Kenwood is loved by him.  Very knowledgeable on these pieces and can likely tell you right where to look.  You can also pack it off to him for repair as well.  He'ss still in the KC area I believe.

If you are tossing it, I'll be glad to pay shipping to me!

Russellc

[orthobiz]

Thanks for the detailed reply. I gotta get cracking on this unit. I'll post picks if I crack open the case.

Paul

[baldrick]

If it is just on the phono input then I'd check very carefully the selector switch.  It probably experiences the most wear than any other moving part in the unit.  More so even than the carbon potentiometers since once the lubrication on the selectors dries out it can experience accelerated wear.

Perhaps it's just oxidation or other deposits on the selector switch contacts.

Take a look at the circuit path for the phono section.  IT won't be easy - units of this vintage are usually packed to the gills with components.

[AVnerdguy]

Definitely clean all the switches. I serviced a lot of these and the most common problem was dirty switches (one channel intermittent). The tape monitor switches were the worst - especially if when not used much. Sounds backwards but it was the most common cause of channel drop out.