Datron 1072 IP-0 displayed

[moebius326]

Hello All -

I purchased a Datron 1072 a few months back and it has been (seemingly) working well. Today I turned on the unit and it displays IP-0. The unit passes self test, but will not otherwise function.

The manual defines the Cause as "Input Zero memory error" and suggests the Correction as "Repeat input zero procedure."

So, this raises several questions

   How do I perform the Input zero procedure?"
   Does it require the Calibration mode (I have the key)?
   Is this indicative of a current - or imminent - failure?

Your help is greatly appreciated -

Thanks -
moebius326

[dacman]

IP-0 can be cleared without being in the calibration mode.

1) Short the input
2) Select DCV mode
3) Press the (Input) Zero key

I think that it will zero all ranges if in Auto Range mode, or just the range selected otherwise.  Ohms can also be zeroed, if fitted with that option.  Check the specifications.  The 1072 may need to be zeroed within 15 minutes of usage in order for the unit to meet specifications.  (This is required on some Datrons, but I haven't researched a 1072.)

Those units are notorious for electrolytic capacitor failure.  If you have a decent LCR meter, I'd check them all, especially the (blue) ones located at the front top left (and the ones on the rearward power supply).  There are about 11 aluminum electrolytic capacitors in those type meters.

I'd recommend the following:
1) Check the 5V power supply (it's adjustable, set to 5.1 Vdc)
2) Check the lithium backup battery
3) Check the 15V supplies for dropouts (with an oscilloscope)

Another problem with those units is that there are a lot of socketed ICs, which makes for easy replacement and troubleshooting, but the socketed ICs can develop high contact resistance and cause problems (like IP-0).  Something else that I suspect could cause an IP-0 error is a loss of power during a memory write operation (but that is more likely to cause a FAIL error than IP-0.)

[moebius326]

Thank you - very comprehensive!
I will try this out tomorrow.

Sent from my SM-G950U using Tapatalk

[moebius326]

Hi dacman -

My thanks to you again.

I followed your instructions, the IP0 message disappeared and the unit was working fine again.

At least it did for about an hour. Then the system went somewhat crazy - all the LEDs illuminated and nonsense on the display. I turned it on and off during the day, but always the same problem.

After re-reading your suggestions, I took the unit apart today, reseated all of the DIPs and connectors, checked the battery (good) and looked at the caps (they look ok). I then powered it up - back to life!!! I checked the operating voltages - all good.

Fingers crossed (very scientific) and hope for continued functionality.

Thanks again, again.

moebius326