Made some progress today with the Thandar SC110 mini portable scope, stripped it down for fault-finding and after a good long coat of looking at under magnification I have so far failed to find a smoking gun, it really all looks pretty good to me. All the solder joints that are visible without further stripping seem to be in good condition, maybe I might find something lurking beneath the vertical and horizontal board once I remove it, who knows.
I find a few caps with small holes in them, but they exhibit zero outward signs of suffering, the holes appear to have been there from new .
Here a few pics so far, I doubt that I shall be working on it tomorrow as I shall be over at Hangar 11 collection, working on that Ferguson TE20 tractor restoration.
That tant on the far left. What is that black at the base? And it looks like it has a crack in it.
Today I finally got that board disconnected and removed and that tant with the black bit on the bottom is perfectly OK. It turned to be solder flux as that leg is top soldered only, I found that in the manual, after I had removed it and tested it.
Still have no sweep, although I have been able to prove that the timebase is running OK and producing a sawtooth wave form and the various time/div positions are all working OK and varying the frequency as it should do. It seems that the problem now resides on the main board, so need to investigate that more. I had thought that the X amplifier was on the plug-in daughter board, but that is just the Y amplifier which is OK according to the observations I have made. That will be another day.