I have this willem programmer: Im trying to erase one of my 27SF512 chips but im having a hard time. I am somewhat new to chip burning so im sure my stupidity is the problem and not the programmer or the chip. If someone could break it down "big bird and barney" style for me and give me a step by step of what i need to do, that would be great. Thanks for any help.... again -Allen

You are using the SST 27SF512. To erase that part you need to pull the CE# pin low then apply a voltage of 11.4 to 12 V to the OE#/Vpp and A9 pins.

If you are having trouble getting the verification values of FFH afterward make sure you are getting the voltage you need to the OE#/Vpp and A9 pins. Without that voltage the device wont erase.

Look at this to make sure you have followed the programmers instructions for switch settings and jumper placements.

http://forum.pgmfi.org/viewtopic.php...b609385bb1cd2d

E

sweeet thanks for the link!!

Pay close attention to putting the jumper in place for erase picture, and the remove jumper for program picture. That seems to usually be the main cause of why users can't erase the 27SF512 chips.

i can understand why, the manual that came with my programmer is shady at best when it comes to describing how to erase these chips.

Yep, very important to have the jumpers in the right places. It took me a but to figure that out, as well.