23-01-2012, 03:19 PM
If the second Y-input channel is only showing a horizontal line - but you can shift that horizontal line up and down the screen with its vertical shift control, and that when a signal is presented to that Y-input, you get the resultant waveform displayed - then that is normal behaviour. If the undeflected trace arising from no input to that Y-input is distracting, then use its vertical shift to move it off the screen.
As for it now "bursting into life", that suggests one of 4 things:
1. Dry solder joint; fix = obvious.
2. Intermittent / dirty mechanical contact somewhere: fix = scrape & clean + switch cleaner. Check all plugs & sockets.
3. Dirty switch somewhere: the T/B switch or trigger selector being favourites: fix = switch cleaner.
4. Something else I've forgotten to mention: but I'm sure someone else will!
I wouldn't ignore that fault, hoping that it will never re-occur: it will!
Although I do appreciate that tracking down intermittent faults can be very time-consuming and frustrating. 
Al.
As for it now "bursting into life", that suggests one of 4 things:
1. Dry solder joint; fix = obvious.
2. Intermittent / dirty mechanical contact somewhere: fix = scrape & clean + switch cleaner. Check all plugs & sockets.
3. Dirty switch somewhere: the T/B switch or trigger selector being favourites: fix = switch cleaner.
4. Something else I've forgotten to mention: but I'm sure someone else will!
I wouldn't ignore that fault, hoping that it will never re-occur: it will!
Although I do appreciate that tracking down intermittent faults can be very time-consuming and frustrating. Al.
