Ok so necrothread revival but maybe this is of use to someone.
Found a replacement switch salvaged from an old faulty mp4 player (generic Chinese tat) which is identical and still fully functional. Spend a while desoldering the old switch, cleaning contacts and fitting the new one. End result - the Dingoo still reboots instead of powering off.
So it looks like it isn't a faulty switch at all causing this, anybody got any ideas as to what might be wrong with it? I've resoldered the battery contacts and there doesn't look to be anything shorting on the board.
GPD Win, GPD XD 64gb, PlayGo, RS-90, 3DS XL, DSi XL, GBA SP, GBBC Clone, Gameboy Pocket c/w screen mod, PSP Go
Medion Erazer, Toshiba Z20t, Dell Mini 9, Psion 5MX
Tons of other old laptops and tablets.....