Hi Again Bob (and all)

So I got my new BlueDSO (bluedso.com) in the mail today and the last one I received was defective for sure as this one works just great. The ironic thing is that when I scope across +5MEM the blips completely disappear. It does an even better job than leaving the chip in as the chip's effectiveness as a blip eliminator diminishes as it gets warmer. There is never a blip heard when the scope is attached making it difficult to observe what may be happening in +5MEM. I took the probe to both C4 and C5 on the UCB and both had proper potential on their + sides so they are not shorting to ground at least. Is there a way I can check them better with my scope without removing them from the PCB

Looking at the schematic I wondered if there was anything in the +5MEM path that would release transients and I thought maybe it could be the battery which is labelled as being made in June of 1983 (amazingly it still works and actually had all the patches still saved after being cased for almost 10 years). It's no longer necessary with the MIDI kit so I removed it from the circuit and still had blips etc. so it's no the culprit.

Clearly some capacitance is fixing the transient. .1uf didn't really help though. I am finding that the smaller the value is the better. I tried the 47pf and it got rid of almost all of them. I then found a small electrolytic labelled 470K630V. I am thinking it is also a 47pf as well and so far it cures the problem completely. So for now I'll just leave that cap in but I'd really rather treat the disease and not the symptoms though so if you have any ideas let me know.

Sincerely,
Rich Clarke