I was replacing two light switches. Turned of power to them. Only after job was done did I notice numerous LEDs lit up on my Optima alarm panel. Pressed reset but nothing happened. Tried to enter pin code but no response from buttons. In fact no buttons respond - completely dead. Power light is on (so is Tamper light).
Don't think it's battery, because that only powers the alarm in case of power cut. Alarm usually re-sets when power is restored. Could I be lucky and find it's just one of the internal fuses? Any advice appreciated.

TomUK, June 2017

Have you replaced it yet?

It would be so good to hear if an answer solved the problem but it's HOW TO MEND IT & people don't do that here :-(

Sally's father, June 2017

like wot he said

Sally's father, June 2017

It's the battery, time for a new one

ynot, June 2017

Optima panel UPDATE
I noticed with power off the LEDs were still lit (except the Power indicator) showing the battery was still active.
I checked the two internal fuses - both ok.
Removed the battery to clean dust off. When I re-connected battery - a bleep sounded and everything returned to normal. Pressed the tamper button and alarm now operating as before. Rather puzzling!

TomUK, June 2017

Should have mentioned that Optima the alarm is on the same circuit as the lighting I was working on.

TomUK, June 2017