Repairing a "Digital" Battery Charger like Exide
Several years ago I bought a "broken" battery charger at a garage sale,
hoping that there was some internal fuse I could replace to make it run
again.
I found out there were no fuses, but with some help from folks that did
understand electronics I managed to identify and replace the blown
voltage controller.
This has been the best battery charger I've ever had - so I was real
disappointed when I tried to use the "car start" option and blew it up
again. This time I took some pictures so other folks might be
able to fix theirs.

Here's my charger. I tried to use it to jump start my motorcycle and it quit again. Time to fix it!

Here's what the inside looks like. 12 volts comes out the bottom
(which is over to the right). Sorry about the blurry photo.

Now here's a photo to be proud of. See that three pin power
component on the heat sink? THAT little bugger is what delivers
the power to the battery! The original component was rated at
55amps, but the best I could find was rated at 30amps. I know now
not to try to use it as a starter again. The component that this
charger used cross referenced to a "NTE5460". I use the NTE components
because they have them hanging on pegs at the Fry's a couple of blocks
from my house. Other chargers may use different components, so
cross reference your own part. Not cheap though, the part was almost $7!
I disabled the "car start" option on my charger since it obviously
isn't really up to the abuse that both the original owner and myself
submitted it to.

Charging away. This is the most effective battery charger I've
ever had, but I'll still keep an "analog" one around just in case!
Now go fix yours!
Here's something I learned as a mechanical kind of guy messing with
electrical stuff. It's always the little three pin component
mounted on a heatsink!
Worked for TVs, VCRs, amps, battery chargers, and a bunch of other
stuff. The reason they're on the heatsink to begin with is that
they're having to work hard.