4 bank charger issue

[Br4d1ey131]

So, I have a 4 bank charger for banger racing and when I'm running multiple cars, recently channel 2 stopped worked. I took it apart to have a look and couldn't see anything obvious. Tried the multi on the output and its a volt under the input voltage which is strange as the rest are at 0 volts when not in use. http://rclife.co.uk/GT-POWER-X-Drive...attery-Charger this is the charger I have. Any recommendations appreciated, thanks!