If the 12V Ni-Cd Akku inside, take it out!
Open the case and cut the big cmos-battery from the mainboard.
Often is bad and the WLTC would not boot.
The WLTC needs 18V + inside - outside, the original powersupply supports 21V 1,6 A.
Otherwiese 12V (old PC-powersupply) to the Akkuconnector...