I see some others having good luck and leaving feedback so figured I'd uipdate.

Quote Originally Posted by Six_Shooter View Post
Some EPROMs, due to the voltage needed might require an external power supply. If you burn out your USB port, don't go blaming the programmer. ;) The USB port is only 5V and 500 mA. Trying to bump that up to 21 V will draw a LOT of current from the USB port, The GQ-3X also has a power port, but is only needed for the EPROMS that require a higher voltage to program, as well.
There is some truth to this. After using the Gq-4x for 2 years on one laptop I never had issues with burning chips without a External Power supply. Well that all changed when I changed laptops. Chip burn went fine and the lights all did the same thing but chip was no good? Took a while to figure out but broke out the old laptop and it worked fine! So I bought the wall wart power supply and it now works on all laptops I tested it on.