The HP T-620 Thin Client is a powerful little machine, that with ease can be hacked into using a random 19VDC PSU and run Windows as any normal PC, easy and cheap PC!
This thin client was thrown out, without anything else than the box itself, no power supplies, no nothing.
The port and connector layout from the manual shows that the HP T-620 models needs a 19VDC power supply. A little searching showed that it was not as simple as just supplying it with 19VDC. HP has put in a few tricks to make a “smart laptop charger” so that you can only use their chargers.
The “smart laptop charger” restriction can be bypassed with a simple current limiting hack as per this little schematics.
All credits for this hack goes to: http://nerdipedia.com/wiki/tiki-index.php?page=Smart+laptop+charger
The machine itself is powerful enough to put a little work into modding it into a PC, running Linux or Windows off a USB disk or for some models, you can even find a spare SSD slot on the motherboard, unlucky for me, this model does not have that option.