It could be a bad voltage regulator, but it is most likely a solder short from a pad to the ground plane. The bottom of the board is filled with a ground plane, and sometimes a bit of the black solder mask is burned away accidentally and the copper is exposed. If a solder joint accidentally connects with this ground plane, there is a short.
Make sure that none of your solder joints are accidentally going beyond the solder pad and connecting to the ground plane underneath the black solder mask. Look especially at the solder joints marked in the image below with red circles. Sometimes there is a bit of extra solder that can be removed. Also, if you can take a good, high quality photo of the front and back of the board and post it, I'm happy to have a close look.
Of course, if there's no easy fix I am happy to send you a replacement. Where are you located?
- Hackvision 5V pins
- board_vcc.png (33.94 KiB) Viewed 1489 times