Norton posted:gunrunnerjohn posted:Pete, I see that Adrian beat me to it, 8V P-P is too low, that indicates that probably two of the four gates in the 244 have already failed. You should be getting around 14-15V P-P with a properly functioning TIU, see my previous post before and after replacing the 244 for the failing channel.
Ok, I rechecked mine using a transformer on Fixed 1. I get 12v P-P on Fixed 1 and 14v P-P on Fixed two which I never use. I expect the two variable channels are fine as week as they never get used. I will order parts to have on hand but hold tight until something breaks.
I have to say it seems odd that these devices fail gradually instead of with a bang.
Pete
Whoa! This is a new twist. So in your initial measurement (8V P-P) the 12V DC wall-wart was into Fixed1?
Anecdotally, DCS operates better on DC than AC. But in this sample of 1, it appears going from DC to AC increases the DCS signal level from 8V P-P (on all channels) to 12V P-P (Fixed1) and 14 P-P (Fixed2). Hmm.
As described in earlier posts, the ACT244 is the originator of the DCS-signal. That's a 5V IC chip. It does not matter what the TIU power source is (AC or DC). AC and DC supplies are or course not created equal, so it could be that your particular AC and DC supplies load down the DCS signal differently than two random other supplies. I don't think we want to go down this rabbit hole (yet). So to keep the conversation focused I think it should be specified that we are talking about an AC transformer power source so that everyone is measuring the same thing.
