I just received this amp from the ebay seller dimsen in Germany here to Australia. "Seller Refurbished" for 1300 Euro before shipping.
He sent the transformer separately due to weight. It got turned around once and he had to resend it. It then wasn't addressed properly and I had to plead for Australia post to hand it over to me. I reinstalled it and fired up the 808. Finally.
The thing brought a tear to my eye it drove my SS-AL5 Mk IIs so beautifully.
Then a few tracks in there's a fuzz on the left channel, then it goes really quiet.
So I switched out my 16 gauge speaker wire for 12 gauge hoping that the power from the 808 was just too much for the wire.
Nothing doing. Been playing CDs all weekend and it will sometimes go a few hours without a fault but sometimes it will drop out on both channels, go super quiet, sometimes switching on and off again can bring back proper sound, other times not.
I'm really devastated about this. I've wanted a serious ES amp for more than a decade and have been saving for over a year for this one now I finally earn a half normal wage.
Am I right in guessing bad/dry caps or bad/cracked solders will be the problem here?
Not certain it's the problem, but maybe cleaning the the main volume pot is good place to start? then checking connections from there..
All else aside, I would try like sjoerg said, get some deoxit and spray all pots, it could even be something like a left right pot that is messing up everything.
If its still bad then it could be a cap or something, did you do a search to see if others have the same issue.
Also for 1300 euro I would be fuming, did you contact the seller??? I would find a near by tech and make him pay the bill to fix it.
I'm betting some sort of transistor or MOSFET is crapling out after a certain amount of heat. Diagnosis shouldn't be to hard but repairs...it's from 1993, it hopefully doesn't have too many proprietary chips in it.
I'm not thinking about caps since if anything bad ones tend to be better the more warmed up they are and I'm not thinking dirty pots either. I mainly fix cars and toys and video games though. I'm not a repairman of this specific sort.
Yeah, I have an issue with my carver amp, it will stay on and won't power off when it gets to a heat issue.
But wouldn't that Mosfet be a switch issue rather than giving distortion??
Thanks, can't hurt, then again I'm a clutz with this stuff and have destroyed a few LD players by going in solo.
Reino - Sony ES has a good reputation, I can't find any info on faults like this with an 808.
Thanks for your thoughts Zeta, a guy on AVS forums also basically thought heat was the problem, I'm not so sure, the problem first presented itself on the first CD I played.
Thanks guys for your posts, very nice of you all.
This sounds like it could also simply be a cold solder joint that is flexing as the unit heats up and cools down. I would look at the areas where a lot of heat is generated like the mosfets that signofzeta mentioned as well as transistors w/ large heat sinks.
Once you find these cold joints (it simply is a separation of soldered parts to the board so you will usually see micro cracks), then you just need to re-heat them again w/ a soldering iron to get them solid again.
Thanks LD Fan. I took the unit into the professionals in my area. An old school hi fi shop with 40 years experience. They had it for three weeks and reflowed a ton of dry/cracked solders. They charged me $250 and I got it back the other night.
First thing that happened when I fired it up again was the audio was dead on the left channel for about 30 seconds, then it was good for the next hour. Then some of the same old problems came back, fuzz on both channels, audio drop outs...FFS!
Then for the last few days she's been getting better!? Less problems, more stable sound. Though not perfect yet, better than before. I think I probably need to take it back for them to keep working on. Or get ebay to agree to the exhorbitant cost to ship it back to the seller in Germany.
Hope you get the amp figured out, paying tops for something that is messed up is not a great felling.
Only when you get that deal is it really OK in some situations.
At least you're making progress and something is improving now.
I just inherited a broken Marantz, NR1605 and it's frustrating me since I can't quite figure out what the issue is. Overall, the machine looks clean inside which makes it harder to find where the problem is (no burn marks or funny smells to give me a hint).
Anyway, it sounds to me now that maybe you have some dry caps to deal with now. I don't think you have any issues w/ transistors, diodes, resistors, etc. since I'm under the impression that if they fail they just go bad right away (but I could be wrong too).
Sometimes that's what we have to deal with.
I always wanted a Mitsubishi, HS-U80, S-VHS VCR and I finally got one about 23 years ago that had issues. At first I was frustrated because I couldn't quite figure out what was wrong with it. However, after some patience and actually a lot of luck, I got all the bugs out of it and it's been fine ever since (although I think I need to fine tune the video settings). I would never give it up. Now the problem.... it just sits in my rack and rarely gets used. I treat it more as a water cooler topic at this point but I think I will be making a tape on it @ some point for a project.
Yep, it's all part of the challenge of seeking stuff from a better era.
Well a few weeks ago my 808 dropped out entirely on the right channel, then on the B-pegs started putting DC out to my speakers (!!) I took it in to the repairer again and this time they replaced 2 relays. So far so good, seems to be fixed?? fingers crossed.