Hello John,
Have a look at the link below which is a discussion on Out and About Live about a similar problem and includes a further link to Leisure Electronic Repairs.
https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/battery-charger/27113/
Leisure Electronic Repairs are well known for repairing all type of Hobby / Toptron chargers.
