Modify circuit for Erase data W27Exxx , SST27SFxxx

Figure 1. cut trace and add part

Figure 2. Schematic PCB3 or PCB3A

WinBond Chip (W27E512,W27E010,W27C010,W27C020)

1. Cut trace PCB U5A(pin 12) to ZIF32(pin 26) and add part figure. 1
2. parallel R15(2k2) with resistor 15Kohm for increase Vpp(12.5V) to Vpe(14V) figure. 2
3. Run program Eprom.exe
4. Put CHIP W27xxxx
5. Select Device W27E512
6. short JPx (close)
7. click Icon Erase (It will Erase and check blank)
8. move JPx (open) and Resistor 15Kohm
9. check Blank again
10. load DATA
11. click Icon Program
12. End

SST Chip (27SF256/512/010/020)

1. Cut trace PCB U5A(pin 12) to ZIF32(pin 26) and add part figure. 1
2. Settting Vpp = 12.5V
3. Run program Eprom.exe
4. Put CHIP SST27SFxxx
5. Select Device W27E512
6. Short JPx (close)
7. Click Icon Erase (It will Erase and check blank)
8. Move JPx (open)
9. Check Blank again
10. Load DATA
11. Click Icon Program
12. End