arggh! help driver keeps shorting out in heatsink?

[Purplemonkey]

I have a amc7135 driver which works fine as long as its not in the heatsink, but as soon as i put it in, the terminal points on the driver to the diode are to close to the rim and are touching the heatsink and it shorts out and battery gets very hot. Any ideas how i can insulate them from the heatsink? tried a bit of tape didn't seem to work.

 

[Zeebit]

Desolder the diode from the driver then use some heatshrink

 

[Purplemonkey]

tried that didn't work, it seems its not getting ground through heatsink to driver. it works if i touch the ring on the underside with ground but if i try and put ground on the heatsink as it would be in the ultrafirewf501b . My battery starts smoking. It seems the driver isn't actually conecting to the heatsink on the negative terminal, i tried soldering across it but solder won't stick to the heatsink. I'm completely stumped???

 

[BShanahan14rulz]

find a different spot on the driver to solder to, and cover the old point in epoxy. You might have to modify your heatsink.

+ is just a passthrough from the Vin.

got any pics of your driver close up, and the heatsink you are using it in?