I have a Milwaukie M-18 Battery Charger that is showing zero lights
when plugged in and dead battery inserted into charger.
Yes 110 receptacle is hot..........how do I trouble shoot this ????
Regular charger or fast charger?
EDIT: I'll just assume normal M18/M12 dual charger unless otherwise.
If you want to get inside and start troubleshooting here's what you should do. Remove the four case screws on the bottom. They're dual torx and flat head so you should be able to manage in either case. Once inside, be careful what you touch as depending on how long ago you had it plugged in and what they've selected as bleeder resistors the capacitors in the power supply or the switcher could still be charged up to full voltage and zap you. Follow the power from the wall into the circuit board and the very first component it goes through is a 3.5A fuse. It's got black heatshrink on it for some reason in the M18 charger. In the M12 it's just a regular old exposed glass fuse. I wonder if that was their "poor man's" HRC fuse? In any case, take a volt-ohm/multimeter, put it in resistance mode and measure the resistance between the two points indicated in this picture:
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It should read a very low value. On my charger it reads under 1ohm. If that reads "Infinite" or any high resistance than your fuse is most likely blown. You'll need a soldering iron to replace it as it's directly soldered to the board. Also, replacing a blown fuse without seeing the reason it blew usually just means you'll blow more in the future.
If your fuse shows a low resistance then it is most likely good. Move onto the next trouble area, power supply caps. These use somewhat crappy CapXon capacitors in them so I wouldn't be too surprised with a failure every once in a while. If you follow the fuse to the big piece of folded over aluminum, underneath you'll see two large cylindrical electrolytic capacitors. Check that they are not domed or have any damage to the tops. They should look like in this photo if they are good:
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Nice flat caps with the foil intact. In addition if the capacitors failed it's likely some electrolyte would have come out of them and there'd be some liquid/gel around the base.
Example:
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If you don't see any of those signs of failure then the problem will probably take some more in-depth efforts but those are the two easiest quickest things to check on it. Let me know what the results are and we can try to figure it out from there. Also take a good survey around the board. Failed electronic components usually "look bad". They will be black/brown with char around them on the board surface. There may also be yellowing on wires or on the board from heat. ICs (Little black retangular bug looking components) will have a hole blown through the black plastic. If you see anything suspect, take a picture and share it here.
I am always trying to get a hold of broken Milwaukee tools to fix and have had no luck so far.