For sale? No, i do it myself.
I used a buck converter dc to dc to converts the 12v to 3v to power the po's and i removed the external plug power connector and switch.
Link to buy the converter:
RfcAAOSwabhUYcNT" target="_blank">http://www.ebay.co.uk/itm/LM2596S-DC-to-DC-Buck-Converter-Adjustable-Power-Step-Down-Module-1-5-35V-UK-/361209263228?hash=item5419bff47cRfcAAOSwabhUYcNT