Wahl trimmer 9900 doesn't work, even with fresh batteries. what could be the problem

SOURCE: how long to charge wahl envoy hair trimmer for?

LEAVE IT ON CHARGE FOR 4-5 HOURS

SOURCE: Where can I buy attachments for Wahl Super Taper.

Manny's Sharpening has the Wahl attachment for $3.00 ea any size from 1/2" to No 9 323 263-4697

SOURCE: need rechargeable battery for wahl cordless

[email protected] he is a Wahl Dealer

SOURCE: How do I split the case of my Wahl 9916C beard

Bottom side (black on mine) has a finger grove section that comes off with a small flat blade screw driver used to pry up, 4 tabs, one on each corner (Exposes 2 screws). Need a sauder (spelling not my thing) gun to remove and batteries are 2 ea 1.2 v (looks between AA & AAA size). I'm just going to just buy another unit. Good luck!

SOURCE: what is the replacement battery for this trimmer?

I have a 9918C. I dabble around with electronics from time to time so I took it apart, desoldered the battery wires and took it out and just soldered the wires to each other pos to pos, neg to neg. The battery was 2.4v and the adapter was 3v and it ran too hot so I put a 2.2 Ohm resister between the positive wires and it runs beautifully now. If shaving/trimming with it plugged in is undesirable then you may want to get a battery but I had to plug mine in all the time anyway because the battery was about shot so I am used to it. Now I just plug it on and go without any recharging or battery worries.