I had to use the same technique on a doxport dp1110 after I jtagged the wrong firmware into the flash.In my case I removed r70 which later I found out is a pullup resistor going to ce on the flash chip.With a jumper across the missing resistor and cycling power the flash was detected as FFFF FFFF and removing the short it finally detected correctly.I replaced the 10k resistor and was able to erase/program again.