can you see what your voltages are at in the bios with each diferent power supply?
there are few reasons why pluging something else will help
1 it drops power going to the card meaning the card is probably overheating (is the card hot)
2 you have a connection problem and doing this some how completes the circuit getting rid of the stray voltage or grounds it
3 you are geting spikes in your power so plugging something else lessons the spike
4 the new power supply has a bad regulator (could be high or low or not true dc bad filtering)
are you using a ups or any filtering on power supply?
there are few reasons why pluging something else will help
1 it drops power going to the card meaning the card is probably overheating (is the card hot)
2 you have a connection problem and doing this some how completes the circuit getting rid of the stray voltage or grounds it
3 you are geting spikes in your power so plugging something else lessons the spike
4 the new power supply has a bad regulator (could be high or low or not true dc bad filtering)
are you using a ups or any filtering on power supply?