19-04-2011, 04:51 PM
My earlier hopes have been dashed. I'd realised that the current symptoms are very like the trouble I'd had when I switched it on for the first time and that had been down to R20 having gone high. I checked that again and it looked like it was reading over a meg, as opposed to 680k, so I changed that again. This made no difference and when I tested the 'bad' resistor out of circuit I found it was spot on.
I can find no broken tracks or dry joints and have had a poke around between the tracks with my megger and can't find any conductive bits either.
I'm loathe to do much more as repeated de-soldering and soldering isn't going to do the PCB any favours. Is it possible that the EL84 itself could have an intermittent fault? I'm loath to buy another without being sure as they're not cheap and I don't have another radio that uses them so it wouldn't be that likely to be of use on another job; it isn't as though I'd dropped it or anything.
So far I've been philosophical and thought how for all that in some ways it would have been nice to have changed a couple of capacitors and then plugged it in and it have worked perfectly I wouldn't have had as much entertainment or really learnt anything. It is now though starting to cross the line into becoming a pain in the rear.
I can find no broken tracks or dry joints and have had a poke around between the tracks with my megger and can't find any conductive bits either.
I'm loathe to do much more as repeated de-soldering and soldering isn't going to do the PCB any favours. Is it possible that the EL84 itself could have an intermittent fault? I'm loath to buy another without being sure as they're not cheap and I don't have another radio that uses them so it wouldn't be that likely to be of use on another job; it isn't as though I'd dropped it or anything.
So far I've been philosophical and thought how for all that in some ways it would have been nice to have changed a couple of capacitors and then plugged it in and it have worked perfectly I wouldn't have had as much entertainment or really learnt anything. It is now though starting to cross the line into becoming a pain in the rear.
