No headlight

Hi- Ive had two GS's and Ive fitted HID's to both without any issues. OK, Ive had a ballast go before- but that was mainly due to the Dealer jet-washing the bike...
Anyway- I had no headlight on the way home tonight- but the Main was ok- both are HIDs
Got home, removed what I thought was the offending ballast, then the bulb- checking both and they are ok. They work off a spare battery.. Ive a few spare sets as I had them on my lastr car- so plenty of chances to fit others for the test.
Now, as theres no fuses and I cant get a headlight working- I get the usual LAMPF up- any ideas?

Ive 'sort of' solved the initial problem- No front light- by replacing the HID with an H7- Id not got any spares when I wrote the post- but I thought as Id tried 2 different HID packs- that I know both work-then trying the one that had been fitted to the bike for the last 2 1/2 years- I assumed the problem was with the bike/ecu.
Anyway- Im going to run with the original set-up ofr a few days as Im less dependant on bright lights now its spring. Ill definiltly go back to HIDs as they have certainly saved accidents over the years as cars DO see you!

ive read posts on here that duff battery can cause this- even though the bike starts fine. The HIGH beam as also an HID- for completeness- Ive replaced that for the moment with an H7 Bulb.

Mine faults if the battery is low, usually fix it by unplugging and then re plugging the ballasts, when the ignition is off! When the bike is getting plenty of use and the battery is well charged it doesn't seem to be an issue.
Mark

Well, as you were replying- I was out having another go and drew the same conclusion as you- the battery may be low. I do 100 miles per day on average- my battery is a fibreglass mat one and is about 14 months old- so it hasn't lasted long. Ive gone back to HIDs and my high beam works fine- it did before all this. The low beam works- but I get a permanent LAMPF on. Im on new lamps/ballasts for both lights- Ive got spares as I sold my old car and removed them...

Just been out for a run and LAMPF extinguished after about 300 yards...odd..

I'd call that fixed then!
Mark