So I recently garbage picked an old multi-function receiver from the garbage room in my friend's apartment building. It's a Sears Electronics RE-1209, which apparently is a model they only ever built/sold here in Canada. It's got both a cassette and 8-track!
Anyway, I brought it home, and the front lit up all pretty! (see below) So that was a good sign!
I plugged in headphones and tuned in CBC and ... well, it sort of worked. The signal strength meter was working perfectly, which was a good indication that the FM demodulation circuit was working. The problem seems to be in the amplifier circuit, as the same problem occurs over all the different functions (except the 8-track, which I couldn't test because I don't have any handy). The sound is very crackly and faint, and if you fade all the way to the left you get the right channel, and if you fade to the right you get nothing. Which makes me thing there's either a short or a bad part somewhere.
So, I opened 'er up! It absolutely REEKED of electronics manufactured in the 70s/80s. I can actually smell it from a few feet away. Visual inspection went well until I noticed the capacitor in the picture below. It seems to have some leakage on the top, and I know it's hard to see in the picture (it's almost as hard in real life!). The bubble shapes on the top of it are very small. The vents seem to have the same color liquid dried in them. Similar caps in the area don't show any such deformities so I'm thinking it's this cap which is the problem. It happens to be right smack in the middle of the amplifier circuit as well. I found a matching part on Mouser, for between $1.38 and $2.15 (depending on brand). I know with audio caps you definitely need audio grade (which they are) and you want to match the part as closely as possible (which I have).
Anyway, my question is, is it probable that it's just the one cap? I can post more, better pictures tomorrow. My phone camera sucks but I can use something else to take the pictures tomorrow. I wish I still had my Blackberry PlayBook, it takes 1080p video! I remember my dad telling me that it's usually a good idea to replace as many of the electrolytics as you can in old electronics like this, because most of the time you can trace problems back to them. All the other ones seem to be in good shape though, it's just the one that looks a bit funny. I blew everything out with compressed air and it definitely looks a lot better inside, the tuning mechanism doesn't crackle anymore.
Anyone with experience in repairing old receivers like this, your advice on how to proceed is much appreciated! I managed to find a schematic online but unfortunately it's pretty low resolution. It's attached also.
Thanks for any help!