Replaces TI99/4A power board to allow it to be powered with a 16v to 18v DC Power Supply Make sure to check the pinout on your original power board, the pinout is the same as my (UK) model but i've heard there are different pinouts on other models, so you may need to make an adapter cable - V7805-2000 https://www.digikey.co.uk/product-detail/en/cui-inc/V7805-2000/102-2175-ND/2352134 - V7812-1000 https://www.digikey.co.uk/product-detail/en/cui-inc/V7812-1000/102-1718-ND/1828611 in the UK i've had success here: - https://www.enrgtech.co.uk/product/dc-dc-converters/ET11313633/V7805-2000 - https://www.enrgtech.co.uk/product/dc-dc-converters/ET11831634/V7812-1000 The Original TI99/4A Power Board is REALLY thin, I made this at 1.6 and it fit, but there was a little fighting with the case. You might want to see if you can get it made thinner, although the ground plane does make that harder. I've successfully made a board with 0.8 thickness on JLCPCB and it works fine #keepITalive