It's been at 8k now for a good half hour. I am leaving it off to cool down to see if I can repeat the fault. I have had equipment that is faulty behave differently at different temperatures. If only I had some freeze spray.I think you have some problems with G3 (possibly).
That behaviour shouldn't happen (i.e. with the oscilloscope probe)...
I would suggest a NOP generator test and check G3 pins 1, 2, 3, 4, 5 and 6.
Dave
Contact cleaner works as a defacto freeze spray, if you put a small pool of it on an IC top, the latent heat of evaporation cools the chip, you can also keep applying it to the one IC and it is one way of localizing temp sensitive chip or component. Sometimes it is better than freeze spray as you can apply it from a soaked cue tip in a more localized manner, the freeze spray spreads out more.It's been at 8k now for a good half hour. I am leaving it off to cool down to see if I can repeat the fault. I have had equipment that is faulty behave differently at different temperatures. If only I had some freeze spray.
Ok it's back down to 4k now.I think you have some problems with G3 (possibly).
That behaviour shouldn't happen (i.e. with the oscilloscope probe)...
I would suggest a NOP generator test and check G3 pins 1, 2, 3, 4, 5 and 6.
Dave
I am struggling to use two probes and take video or pics at the same time safely in fear of shorting pins. I don't have any wire clips for IC legs to attach the probes safely.Ok, there looks to be a problem with your oscilloscope set-up.
Let's not bother with pin 1 but concentrate on pins 2 and 3.
Trigger the oscilloscope on pin 2 (the input pin connected to /SEL1).
Set the trigger mode to CHOP. I think you have it set to ALT at the moment.
What are you running for the CPU to give you these traces? A NOP generator or some firmware?
I am a little concerned that the timebase seems as slow as it is. What have you got it set to?
Dave