Old thread, but did you find anything?
I just got T1600 with broken PSU on flea market - with a few shorted n-channel mosfets. Won't boot, it flashes on/off power led. Same happens when I apply ~8v to battery pins.
I'm recently fixing a lot of switching psu's in old devices, but it's always easier with schematics.
One I got has 286-12 CPU and 40MB. No modem or any expansion fitted. Nice thing is that one of internal batteries (this connected directly to power supply) is on plastic tray - it was leaking, but all contamination was inside this tray, all boards are corrosion-free.