Farnell fg3 with output problem

[Deathwish]

Attached is what i think is the relevant part of the diagram.

After turning it off for a day or so and then turning it back on there is no waveform output. However if I lightly touch VT4 it will output as normal, I don't think it is the board , a break on a trace or such as I can hold the board from the back and it will still do it, I can't see a dry joint or the likes and the traces dont move when it is touched. I did consider, or wonder if it was a capacitance problem with C8 as well but not anymore, it still does it when i use a plastic trimming tool and touch VT4. I would rather not have to remove the transistor but thought I would ask what you think anyway.

[Deathwish]

It was VT4, they sit on top of little plastic formers, it seems that the leg to base was corroded and snapped at the body of the transistor.

[andybarrett1]

 

[Deathwish]

Just so you can see what it looks like.

[Deathwish]

So, my rebuild of this is nearly finished, i had to sort out the output, rebuild a case it came in as it had screws inside to hold the board in that were loose as they were too long, and the pot is off centre and the knob on the pot turns ellipticaly and obscures the numbers on the front panel.

I have a new knob and pot to go in but am waiting for solder to come. Once it does I will then post some pics of it back together. I then need to get some of that black sticky covering stuff to go over the case top.

[Deathwish]

Excuse the state and clarity, only have a phone. Nice new Pot and Red knob and I can see the digits now, the inside was a bit of a spaghetti junction on the mains input wiring so  i sorted that out and will cable tie them up inside . It is now fixed and works first time