Hello,
I have an ADA885 that I've used for over 11 years now, with multiple fixings throughout its life. The first fix was ~5 years in - I would hear the sub cut in and out, and what I believe is the relay flipping on and off. At the same time, the LCD display on the right speaker was stable, so I am pretty sure the satellites were fine. To fix this, a coworker at the time who was a hardware engineer resoldered (and possibly replaced) a bunch of caps on (I think) the larger, multi-story PCB board - the one that receives the signal inputs and has the large heatsink.
More recently, about 3-4 months ago, my system would start cutting out in a similar way as before, but it usually happened once the system *heated up* (was on for hours). The whole sound system would start stuttering as if it had intermittent power. The LCD on the right satellite would turn on and off, or stay somewhere in between and become faint, or look like it is flickering on and off at a very high frequency. Finally, I think the system started to turn on and off (relay sound?) again. This time, my dad helped replace the 3 large caps on the same multi-story PCB, because we decided that they leaked out -- they had a dried brown liquid on the bottom.
So, after that, the system was stable for about 3 months. And now it started misbehaving again. Similar as last time, the LCD would become faint/flickery (but possibly stay at that stage for a while - music plays just fine throughout this) OR the system would start turning on and off very quickly (relay can be heard switching on/off again). This time though, the system did NOT need to heat up first. This would happen randomly, sometimes immediately after I turn it on, sometimes hours later. Also, I would be able to get it to stabilize with the use of some percussive maintenance (I know how horrible that is, yes). After that, it would stay on just fine for hours until I turn it off for the day. I think that lately, the issue happens as soon as I turn it on on the next day. Because of this, my dad and I believe it might be a matter of something (cable, components, etc.) not making a good contact, or perhaps a cold solder joint... we just don't know.
Anyway, I am not sure if Kris (or anyone else for that matter) is still at this forum and would see this, but my question is -- does anyone have an idea what the problem may be? I have dismounted the second PCB (from the sub speaker compartment), and see that all the large capacitors have the dried brown liquid on the bottom. A simpler question, I hope: in the pics here:
https://picasaweb.google.com/113065125154002109926/ADA885
have the capacitors leaked out? Or is this some sort of glue that was used during construction? It looks like a leak, but then in one pic, near the inductor (coil), there is a clearly visible drop of what looks like the same brown stuff as is under the capacitors. I can't tell if this is by design, or perhaps a spray from the caps, or neither :/.
My current plan is to have all the caps replaced regardless (just ordered new ones) and possibly fix some possible cold solder joints on the bottom of the PCB (sadly, nothing looks obviously wrong to my "Goolge-images-trained" eye).
