Mains Supply indication missing

My Auto Sleeper Devon accepts mains power, but the 'lightning' symbol on the Control panel does not appear. Mains circuit in the motorhome works, and I assume the battery charger does. I have a solar panel input as well so I'm never quite sure. The symbol appears, according to the manual, when mains is connected and the charger is switched on. The charger is switched on at the EC500 Power Supply Unit on the floor, but the only thing unusual there is the blue  'on' light flickers.    Any ideas please as to the missing symbol?

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Richard

Is the charger switch on the main EC500 unit illuminated green, as normal?

Yes the green light is on...( I said it was blue in my first post...sorry) but fllickers slightly

Ah, Ok - the colour caused me some confusion. I'm not familiar with the EC500 but if the charger light is flickering then there must be a problem somewhere. Just to be clear: you have an EC500 control system and an EC480 control panel/display and it's the small lightning symbol in the header at the top of the screen that you're referring to?

You should be able to diagnose the problem further, but the first thing you will have to do is eliminate the effects of the solar panel, either by disconnecting it, or by covering the panel, or by carrying out tests after dark.

The simplest thing that you need to find out is whether the charger is charging the batteries. Probably the simplest way to do this is (with the solar panel isolated) to turn off the charger and leave the system to settle for an hour. Note the battery voltages and then switch on the charger. You should see one of the battery voltages rise above 14 volts - it won't be possible to predict which one as you ~probably~ have Smart Charging enabled.

If you don't see that happen, there is a problem with the charger output (as opposed to a problem with the light on the charger switch) - though at this stage it won't be possible to say for sure that the charger is faulty.

Whatever the outcome of that test, I would try to check the multi-pin connectors on the underside of the EC500, as it's not uncommon for these to work loose, despite the fact that they have locking tabs that should click into place, and to check the connectors on the back of the EC480 control panel (though the latter seem less likely as a cause of the issue).

Many thanks....I'll test the charger operation tonight. I'm not into much further investigation as I'd be out of my depth, but it will be enough to know the charger is working or not with winter coming on and a dearth of sunlight.
Workshops are operating with a backlog so are not able to take in work at short notice. but hopefully that will ease with winter.

Many thanks again...your steps indicate the charger is not working, and according to the manual is enough to not illuminate the lightning symbol on the control panel. I'm going to take it to a workshop now.  
Another problem that's cropped up at the same time is the Whale water system refusing to allow fresh water in. This is subject to separate post on this website but I can't see it's connected in any way.