Attached is my attempt at highlighting the waveform test points on the track side of the PCB. Zoom in to see detail. The three signals we are looking at are colour coded as indicated by the legend in the bottom left hand corner. Each test point is numbered to correspond with the oscilloscope diagrams (1-18) extracted from the Technical Reference document (see post #40). I’ve done my best to minimise the effect of flash flare so that the areas we are interested in are clearly legible.
Notice that some of my test points don’t appear to be in the same place as the ones shown in the image posted by Sirius. In terms of connectivity there’s actually no difference between the two. For example, we’ve placed 18 on different solder pads but these are both connected to the case/collector of transistor Q721.
I’ve no idea whether or not pudwink is finding any of this helpful but at least the track side view will add to the bank of available PET resources. With that in mind I’m also attaching a cleaner version of the PCB (track side) without the test points relevant here but with various enhancements.
Alan