Dimmer and Relay Unit C-Bus & Unit Lights alternating flashing - bad units?

Help if possible - before spending thousands $$$ on new units!

Last week 3 L5504D2UP dimmers and 2 L5512RVFP relays stopped responding to any messages from input units or directly via ToolKit toggle via their lighting channel group. I have around 20 output units on the network and the others are all fine - the network has been running for years.

The bad units alternate their c-bus and unit LEDs which flash approx 6-7 times then (seem to do) a very brief pause (less than 1 sec) and redo the flashing. If a channel is held down for 10 secs then the that channel will come on and stay on and cannot be turned off. If you redo the 10 secs to another channel that will be the one on and the other off. The unit doesn't go to normal learning mode - something I haven't generally used. Even without c-bus cables connected (but with 240v into the unit) the LEDs will do their alternative flashing.

My understanding of this is that the unit is saying there has been a local override (unit light flashing?) and also there is not sufficient power on the c-bus network (flashing c-bus light) - but the voltage reading on the diagnostic network scan is 29v and not unit is below 25v - the inability to toggle learning mode and out again normally seems odd.

Despite being scanned on the network I cannot save the 'bad' unit back to the network. I can't see any specific errors in the logs either. If I toggle a channel on a bad unit the logs show that having been done.

Any help would be much appreciated.

Thank you.

 

I've reduced the network to a just CNI and one (apparently dodgy) relay with a built in PS (hardware burden). The inbuilt power supply is providing 34.3v and I have created a new project which opens and can scan and load the relay unit via toolkit but cannot save back to the network. The unit and cbus lights flash alternatively. Again with a slight pause after 6/7 alternative flashings. The flashing also occurs without any cbus cables connected from the CNI. Any suggestions welcome.

 

[QUOTE Any suggestions welcome.[/QUOTE]
assuming that you still have sufficient network power with all the other units connected, have you tried to power up the installation with the dodgy unit out of play?
Its happened to me on a quite a few occasions where a faulty unit with PS was now not only not supplying power but also drawing excessive network current and/or spitting out lots of excessive network traffic.

 

Thanks for the reply - if I bypass the faulty units the system is ok - even with them connected it works but those units do not respond to any requests via toolkit or from key input units. I have a feeling the 2 relays (1 with power 1 without) and the 3 universal dimmers (1 with power 2 without) are now faulty.

It is the alternative led flashing that confuses me (even with no cbus cables connected) - that 'seems' to be learn mode but holding a channel button down for 2 secs does nothing. I've had the site power off for 30 mins to see if it resets anything but no luck. The other odd thing is when the power is turned back on to the relay that I'm testing all 12 channels turn on then turn off.

 

[QUOTE.

so does that mean that with the faulty unit bypassed you CAN save and backup?

[QUOTE I have a feeling the 2 relays (1 with power 1 without) and the 3 universal dimmers (1 with power 2 without) are now faulty.
.[/QUOTE]
Its possible but highly unlikey that 5 devices are going to crap out at once-even if hit with a power surge. Once again, its a common symptom of a faulty PS. Hope that you find the problem soon.

 

Are these 5 units in the same board feed from the same supply.
If so check the mains voltage
Run a separate supply to the units
As 5 units are showing the same symptoms check any common elements
Anything local that may be influencing them RF transmitter as an example.
C-Bus cable feeding them
Your idea of testing one on its own is a good idea but pull it out of the board and include an input unit in the small network.
I have seen output units behave strangely when there are no input unit to communicate to.

 

Thanks for the suggestions.

All other units can be saved (physical and network) even with faulty units on the network but the 5 units with the flashing cannot be saved to network/physical (only database).

I'll try running a separate supply as suggested and with an input.