Whilst I think that most now agree that the signals should have been level-shifted, that does not explain how a clock that worked for ages suddenly goes nuts... good point that actually - was it a sudden fault or did it slowly get worse?
I would start by swapping the hv drivers over and seeing if the problem moves, scoping the 5v rail to look for noise and sag, removing the hv drivers and then replacing one at a time etc. i.e. elimination. Theory is great and interesting but won't help much in solving the immediate mystery... Nick -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/96584fe9-dce0-47e6-a0dc-bd31ddc23411%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.