LRS-3

This one started in January. Three stop, front only, homes on 2, 1st floor locked out. ROA. Complaint car not opening doors at 3. once I caught it doing it, guess what wrong place wrong time. Checked all power supplies. Seemingly good. But then runs fine. Another call, doors open, car six inches low on 3. But ROA. Reed switches, didn't help. Next call, DOA .Change AC tap on transformer for COP power supply. Although it says 9 VDC on print had 11VDC, now 13VDC. Car runs fine. Next call DOA, Change power supply in COP, Car runs fine. Next call DOA, Change MCB, car runs fine. Next call DOA, jump regulator on RB1 YEAH. Ran for 2 days. NOPE. Change C1 Cap, was 27.6, still 27.6 you got it, NOPE. change DRF1, NOPE. POR, car makes one trip, either up or down, 2 floor or one floor, doors open buzzer goes off, doors close, door open button works, no car or hall calls. It will shut down even when it homes. Next is RB1. Any other thoughts............

Are there window covers on the Eproms? U65, U66, U67? U64 is the contract chip. If you have an eprom burner, verify checksums.

Well RB1 didn't do it, Makes me think more, so do you suppose it could be the tone board. It would be a surmisation, but, if it stays at the floor I can open doors all day long, then make a run, Dead. Even when it homes it pukes without doors, so that takes the car lantern out of the equation. Losing sleep over this one..... Rolly, unfortunately I don't have a burner, and yes they are covered. New MCB, almost had that AH-HA moment when I replaced it though. the old board was discolored where the door inputs were. DOL and DCL change states correctly.

Have you tried the cpu power supply? That supply is a voltage doubler circuit and uses the caps for that. They get ripple in them, To much ripple damages Ram chip. You could try replacing the 2 big caps on the power supply in the car panel, it has been in service for many years.

Rail guide DBG too wide (car falls to the opposite side of the inductor box) maybe making DZ intermittent?
Failing DZ relay
Failing DZ cartop inductor? (Reed switch you say?).

Rolly, yes the cpu power supply was changed. El, thought the same, moved rails in before I changed the Hatch Proximity Switch interrupters, is what SEES calls them, yeah it can be called an inductor, in February. All new relays again, New RB1. DZ is up. Checked RV relay in COP, it's working fine, tried even to jump the contacts (a sagging voltage) and make a run, failed. I could understand if it didn't make a perfect run up or down, mis-level, no doors, wrong speed, miss a slow down, not stepping. But it's doing it all right ONCE in either direction. even multiple floors PI is also changing correctly. Floor passing gong works. I hate to think that the contract chip went bad. Usually when they go bad they are done NOW, not intermittent. But its definitely something now. I'll be working on it today and not till next TUE but I'll let all know. Thanks for the help.

It seems to be running normal, just not opening the doors on occasion, is that what I understand so far?
“Door open buzzer goes off”...as in delayed close...nudge buzzer?
Sooo maybe the door operator itself?
DO /DC relay on cartop?

Keep us posted with your findings.

Do you know what kind of door operator is on it???

Sorry for the delay, QL door operator. Still in the woods.

Does the unit have a screen or safety edge? Make sure what you have is not firing intermittently when car is coming into floor. This can kill door time.

Well, I'm putting this one away. When checking for a ground, found wire out of terminal feeding rem, which was off-line but what the hell, put it back, fired up rem( w/out Otis line worked for a week). Same s>>t. punched all wires in COP. good for two days!!!!. Well lo and behold, bad DZ switch out of the box, intermittent at best. One of the first places I went, WTF.... Running for three weeks now. I would like to thank all for your input, and El, I never went back to the (NEW) switches, Why right.

Good afternoon all. I have a Otis LRS3. Car was running then all of a sudden it stopped working and now tries to go on fire recall. Car will not run on inspection or normal. Checked Saftey and limits and all are good as well as all fuses. Any feed back would help. Right now The car is below the floor by about 4 inches. There is no low pressure switch as this is a Hydro or a final limit

That buzzer you hear may not be fire recall. I had problem with switch tree on top of car and heard that buzzer also . Those marsh Mello rollers are problems as well as the older door relays in controller .. Unitec sells an upgrade for those because they had a high point of failure

Do you have a runx relay. Try pulling that