CLC board DMC Elevator Fault

Hi guys

I have a problem with DMC elevator. I can't stablish comunication between CLC and FAST. Also I have fixtures TURNED OFF, calls buttons activate and deactivate. This is the first time I have communication problems with this elevator.

I checked R5 and R6 resistors on 6300BP4 CLC are not working, it looks an open circuit if you read with multimeter. Does anyone know the R5 and R6 nominal values to replace?

Regards

Try unplugging the selector,then the door operator.

I did it already. Same problem

Power supply issue? I’d check that.

10.75V, 5~5.1VDC from power supply are correct.

Also 150V and 120VAC.

Did you ohm out the communications plug? On the board, it should be open from pins 1-3 and 460-480ohms pins 2-4. Does the LED on the CLC board come one and stay on?

Replacing the resistors is probably not gonna work as it's not fixing the underlying problem (what blew them?) and there's a good chance there's other damage.

Replug your communication cables. With power on replace you 3v battery backup on board. If it still doesn’t come up, then your CLC board is bad.

I removed LCC9 and LCC10 connectors, to read the harness resistance. Everything is ok, pins 1-3 are open and pins 2-4 shows 472 Ohms. The CLC LED is ON. I don't want to remove the CLC battery because the CLC data will be deleted.

I have doubt with the resistances because are old and overheated. The current CLC board was made in 1998.

Replace CLC. If you try and plug service tool directly into CLC with selector and door disconnected and no comms

Where are you checking the power supply voltage? Checking at the supply is a good way to get fooled. Also, do you have any ripple on the supply output? Check 5 volts at the CLC.

Negative lead on the CLC ground test point and positive lead on the right hand side of C48.

That toggle switch has gotten me a few times.

Does the red watchdog led come on?

Since the CLC LED comes on the CLC software is running. With a bad power supply you don’t get the watchdog. Can you talk to the selector and door with everything plugged in? If you can, replace the CLC, if you can’t, make sure you have at least a meg ohm from PSC to ground and from NSC to ground on the harness without comm plugged in on all 3 cards. Also try removing the “trans orbs” that go from PSC to ground and NSC to ground. Comm will work without them but they will take down comm when they fail. If that’s the problem you can let the car run but do replace them.

Watchdog LED is ON. I have 5.1V between C48 and CLC Ground.

I can't stablish communication in any card (door operator , CLC and selector)

I have 2.3kOhm between PSC and physic ground. The same with NSC and physic ground. That data was taken with serial harness (LCC9 and LCC10) disconnected from CLC board, door operator and selector. The problem continues...

Does your service tool establish comms on other Cars?

I think it's time for a clc,from my experience if no comm with other devices disconnected and proper voltage your clc is bad.

2.3K ohms to ground on your harness is not okay. You should have at least a Meg ohm. It’s not he CLC (or at least not just the CLC) if you can’t talk to the door or selector with the CLC disconnected. To eliminate the harness from the equation you can plug directly into the selector and the door with their comm (in) disconnected to see if you can talk to those boards individually. If you can’t talk to anything, you may want to make sure your service tool works on another car as Jluff suggested.

Thank you guys.
I found one of the harness shorted and main selector board damaged. I replaced them and the car is working for now. The communication was recovered.

Thanks for the follow up.

Side note, if you replace (or remove to check voltage on it) the CLC battery with the power turned on you won't loose your settings

I have seen a few pins removed from the jack where you plug in the fast tool. Check that the pins didnt get pushed through or the wire removed to fool you.