Lovely HK6500 breaking

[ajhunter]

I've just picked up a Harman Kardon 6500 for an absolute song. It's briliant, easily outclassing my Albarry PP1 in terms of detail, soundstage, space, pace, everything. At least it did. This evening I put a cd on and there's a horrible distortion in one channel. It's the same for all the sources and the same through the headphones. It seemed to get a bit better with moving the pots around so I gave them a clean and it sorted out for a minute or two, then went back on the fritz.

Any suggestions? I'd really like to keep it if I can get it going again. I've a sinking feeling that it's just too old. It probably hasn't been turned on for ten years and has just gone pop. Sigh.

 

[Pete the Feet]

I had the 7500, whilst not the last word in detail absolutely lovely to listen to.

 

[reddish75]

What did you clean the pots with?

 

[Jezzer]

I used to have one of these, and a HK 6550, a HK 630 and a HK 680! Great amps - though sorry I'm of no use in terms of helping you get your amp fixed...

 

[ajhunter]

I put a tiny little squirt of servisol on. It's always worked fine in the past. The thing is that I probably knew it wasn't the pots before I started - the distortion is intermittent and comes in gradually like a growing background hiss, then disappesars suddenly. It isn't really a dusty pot sort of profile.

 

[goomer]

Did you do all the switches, not just the rotary ones, with the Servisol? I had a similar sounding, intermittent, problem with my Yamaha amp, and in the end it turned out to be the pre/power separting switch on the rear panel, so if you haven't done so already, do all the little switches on the front panel and the speaker operating mode on the rear panel too. Hope you get it sorted.

 

[ajhunter]

I hadn't thought of the speaker mode switch, but I'll give it a go. Would it be worth doing the on/off switch as well? There's something a bit counterintuitive about squirting liquid into a power switch, and I don't suppose it's in the signal path.

I noticed that one of the round ceramic capacitors has a chip out of it. Could this cause an intermittant fault?

 

[budgetblown]

Plenty of recommended repairers threaded elsewhere on this site - give a couple of local ones a ring?