I've got an old e400 that I hadn't used for years. I decided to re-instate it and do various projecty things with.
I bought a 3rd party battery but although it is charged up and I measure 4.2v from it, the e400 refuses to switch on battery power. It will switch on on mains power, but behaves as if it has no charge i.e. shows the reset screen then ask me to calibrate the touch screen. Date/time set to default.
I did read in another post that the voltage might be an issue. If this is the case I can ask for a replacement/refund. I just hope it's not a motherboard problem as it would be uneconomical to repair. Damn and I spend money on a battery and cables.