Home Forums General Discussion Technical Questions Miprom Hydro

Having intermittent issues with a Miprom Hydro for the last few years. Symptoms are in response to a hall call the doors may open half an inch, half way or not at all. Sometimes they open all the way and have no dwell time. Two stops, issue occurs at both landings. Issue also present with car calls. If you hold the button, hall or car, the doors will continue to open.

To no avail, the following items have been changed: all input cards, all output cards, both backplanes, power supply card, power supply, relay board, timer board, SRB, the board next to the SRB (can’t recall the name), door operator board, cable from operator to detector edge, limits in door operator, hoistway switches and traveling cable wires have been swapped around.

This issue may occur one in a week or remain failed for several days in a row.

I’ve finally got my hands on a tool and the car is currently failing.

Moving the run/debug jumper on the SRB yields no action in the debug menu.

Does anyone have any diagnostic information they can share?

Post or pm your email and I'll send you what I have.

I think at this point, I would start looking at the door micro switches. A flaky close limit switch or a loose connection to a micro could be an issue. When the Miprom doesn't know what to do it will try to close the doors. So an input from a micro telling it to open while another input says to close would cause the problem.

Micro switches check out ok and have also been replaced.

I poked around the tool a bit today and spoke with Cetek. We found that my ALU software input was toggling high and low. Also, I cannot get my NVRAM to initialize.

I ran an input test and it looks like the first slot on my backplane is bad. I’ll post my findings once I get my hands on some parts.

Swapped the input backplane and the first input card, input test now passes.

Was also able, with assistance from Cetek, to initialize the non volatile ram.

Car ran without fail for an hour or so and then ALU started getting flakey again and my issue returned.

New I/O interface card is next.

Tried two new I/O interface cards, problem remained.

Replaced second input card and issue cleared immediately, which it sometimes would with a power cycle.

Re-installed second bad input card and issue was clear, ran car non-stop and issue returned after about 30 minutes.

Re-installed new input card and ran two hours, no more failures. Time will tell if this thing is fixed.

Have you traced wires from door operator and saftey edge/photo eye? I had a miprom 1, years ago was flaky with the door operation and ended up having wiring mistakes. I remember mine would randomly ignore the saftey edge/ignore door open time and slam doors closed.

Also dob and dcb?

Operator switches have been replaced and all wiring checks out.

Door open, door close and detector input wires have been lifted while failing and issue remained.

What is ALU? I cannot remember seeing that particular designation.

According to Cetek ALU is a software input that is the sum of several inputs associated with door zone.

The signal is only viewable from the tool, it is not a discrete signal.

ALU = At floor leveling unit.

Not sure if that's relevant though, I think it's only used for group controllers.

When you replaced the backboards did you reuse the little voltage regulators that are mounted on the side of the metal cage and wired to the boards? If so, did you confirm you have a clean 14vdc coming out of them. There should be 2 capacitors on the right side of the cardrack you can measure the voltage across fairly easily. Also, flip to AC and see if there's any AC coming through.

Those can go bad and cause all sorts of input issues. Usually the card leds will stay on or off and it will be a row or entire card but I wouldn't be surprised if it could cause this issue.

Checked back in at the job last week, all is well. I think this thing is fixed.

LAmech is correct on those voltage regulators they can deal you a fit but once you know you know and easly check them. Also on older models with weird door problems remember to check door motor brushes and there are 2 big capacitors hidden under the main operator board with a transformer. I still remember how happy i was when i found them and replaced them and my nightmare call backs went away.