Grundig Concert Boy 1100

[poppydog]

Evening, thanks Mike Noble for the comment, that made real sense so I inspected the top vertical board solder joints for cracks etc. but couldn't find any or any dry joints anywhere else. However, I did remove all the old solder from where the vertical board meets the main board and replaced them with a small fillet of solder (see pictures) (the original joint was very thin) I did this to all the vertical boards. I also removed all the old solder from around the switch in case there was any suspect joints around there and replaced them with fresh solder (I would think those joints probably lead a hard life). I did all this last weekend but I didn't want to post too early in case of tempting fate! After I replaced the solder joints and switched it all back on I went round tapping the boards (quite hard) and it seems to be ok. It has been on every day of the week and is sounding better than before (not so much base distortion). The only thing I don't like is the blue adjustable trimmer on the circuit board - it sticks out like a sore thumb! Also the replacement capacitors are about a quarter of the size of the originals. I am still a little disappointed as I haven't found anything that I can put my finger on and say yes this is the cause. I have learnt hell of a lot over the last month or so and would like say thanks to everyone who helped again (it's probably also been a source of entertainment for others).
Thanks