Problem with 4 channel dimmer

A 4 channel dimmer suddenly started to have a strange behavior. When any of its channels is turned off, the lights still burning very dimly (1%??).
Any ideas please?

Thanks

 

Some more feedback.
When I cut the power off for a couple hours and power on again, for about 10 minutes everything works fine. After that all four channels starts burning very dimly again.

 

I haven't heard of this problem before. Some things to check:

1)What is the dimmer type? Circuitry varies between our range of dimmers and the cause of this problem could be different depending on the dimmer hardware.

2)What type of load is connected? Mains voltage or low voltage incandescent, or some other load like LED or fluorescent? Some load types can glow dimly with very little current (see below).

3) If the load is very low wattage (under 20W), the current that passes through the EMC suppression capacitors in the dimmers can be enough to make lamps glow dimly.

4) Have you checked the minimum brightness setting in Toolkit? If you want the loads to turn completely off the values for each channel should be 0.

 

1) The dimmer is a L5504D2A (4 Channel dimmer 250Vac, 2A per channel, 200mA C-Bus power supply)
2)Every channel has mains voltage incandescent lamps
3)The installation was working fine since last year that we finished the project until last week.
PS: Homegate is running on site but even if we disconnect it the problem remains
<table x:str="" style="border-collapse: collapse; width: 354pt;" border="0" cellpadding="0" cellspacing="0" width="472"><tbody><tr><td class="xl24" style="height: 12.75pt; width: 280pt;" height="17" width="373">
</td><td class="xl25" style="width: 74pt;" width="99">
</td></tr></tbody><tbody><tr style="height: 12.75pt;" height="17"></tr></tbody></table>

 

Blowjob effect

After blowing some air in the unit started working fine.
God Knows why...