YN-468 help

Hi,

I'm wondering if anyone knows of a factory reset method?
I ask because my flash is only firing intermittently - even using the pilot button it only fires every now and again, sometimes it will work twice in a row, other times you could press it ten time waiting 30 seconds between and it would only fire once.

I've tried a few sets of batteries including 2900mAh Vapex and 2000mAh eneloops, all of which work fine in my other flashes.

Any ideas what I can do or should I just give it up as a bad light and replace?

Oh, I will add that eberything else seems to work fine and the charge indicator remains a solid red - which according to the manual means either

or

Although it does also mention a green light being lit, which there isn't.

Gotta love simple manuals