DCT Instruments, Sensotec (Honeywell) J Series Help??

I've googled JKW3KGZ and could find a site of manufacturer. Why don't you call them?

Nevertheless, there are my thoughts of ur trouble:

1. I don't think it was a wrong combination of buttons. Good made and certified device should be foolproof. Its simply should ignore any wrong pushed combinations of buttons.

2. It's likely also that programm flashed into controller is operating properly. You can watch correct indications of digits, therefore there is a convertion from measured parameter to digital output, so ADC is operable along with uP. Here is always some probability of ADC or uP faults though.

3. It's most probable that pressure transducer inside your gauge got broken (zero level out of range). That's why you can't achieve eng unit indication. I'm supposing some logic condition does not allow to switch at this state as there is not passed initial test of permitted zero level.

4. Due to p.3 factory test can't be fulfilled properly.

I can't scan what developers of this gauge kept at their minds, but I'm supposing they didn't invent a wheel.

Therefore it's likely a mechanical problem: broken sensetive element of transducer, broken insulation, etc. It could be a problem with cable and junction box. Have you checked this?

I Googled it long and hard before ever posting here. Not much information online.

Calling Honeywell is like calling the gov!

Have you tried removing battery for a minute or so and see if that sorts it out, since it sounds like firmware maybe temporarily corrupted.