Goldstar TSR-580/1 wire snapped from where?

[thinkchronicity]

First time with the boards out and i see the thin white wire has come adrift from a pad. It's either the one due south of the floaty end or the pad south-east. Surprised the box works so well apart from some hum after warm-up, but there we go. Pic is of the main board. Not too much else visibly wrong with the boards - the ext mic connectors had a cracked couple of pads though, as did the RIF switch.
Hope someone has a photo of their board, would so appreciate it! I did try melting both of the likely pads to find the bit of wire left in it, but no luck.

 

[thinkchronicity]

Remembered that mine is the European version with mono/stereo switching instead of the north american loudness switch. Hence all these wires on the back of the board. Of course (Sod's Law) the manual schematic shows the loundess version so now i'm really stumped. Thing is...i don't know whether i should reconnect this wire in any case as the mono/stereo switching works fine...hmm

 

[floyd]

Those wires look like the type used for audio signals from the tape deck. If you have a hum it might be because of an open circuit in the audio path. Could also lead from any external input such as line in.

 

[thinkchronicity]

Those wires look like the type used for audio signals from the tape deck. If you have a hum it might be because of an open circuit in the audio path. Could also lead from any external input such as line in.

You're right!, those wires i've discovered tap into the l & r channels from the cassette going into the preamp. They go off to the mono/stereo switch where in mono mode the two channels are joined together. The blue wires are from the radio board. So i think i've sussed it, although the pcb layout is not symmetrical - cue lots of neck twisting/shining lights thru the board. Still not 100% sure, but...

The hum is a weird one. No real hum on switch on - gets obnoxious after about 20 minutes. ?
I just replaced the 1000uF, the second largest filter cap. Main cap was done a while back.

 

[floyd]

If you look at what's on the opposite side of the board you might be able to locate the part it connects to by looking at what component at the end of the wire that's still connected and then look for a similar part near the end of the wire that's disconnected . all you should have to do is look on the electronics side of the board to find a part of circuit or electronic part similar to the one that's still connected. These 3 wires are l+ R+ and black for common - ground.

 

[thinkchronicity]

If you look at what's on the opposite side of the board you might be able to locate the part it connects to

Yeah thanks for that, i slept on it and double checked in the morning. Confusingly it actually attaches to a non-complementary resistor for that channel...but is joined to the complement via the traces. Weirdly (again) the black ground wire is deliberately only soldered at one end and the other is heat shrinked off. So just a shield for the two audios i guess. Well, it's back together and works phew. Mono sounds bigger now there are two stereo channels funneling into it, not just one.
Other issues solved were an intermittent vu led (reflowed some pads) a creaking tuner cord (oiled it just enough) and mic-in missing ground connection. Just remembered though a deck issue where sometimes you can't keep FF or RW depressed - and when that happens you get a low fart thru the speakers until the key pops out. They work fine when the unit's turned off so some electrical fault at play. Here we go...