Levo SL Gen 1 Levo Sl intermittent power

[Letford]

Posting on behalf of my friend who's not on this forum. This morning on our ride his Gen 1 Levo SL started giving him problems. Intermittent power at first then nothing at all. No fault lights on the tcu. I happend to have a spare battery in my pack for the tcu so swapped it over and the problem continued. Anyone else had this issue, if so how did you rectify it? He's had the bike since new and it's now out of warranty so can't go down that route unfortunately. Any help would be appreciated thanks!