FLUKE 1502 repair need FW copy

[gearedbyby]

i get a fluke 1502,  it display garbled characters,i check the manual,the diff between 1502 adn 1502a maybe 1502a use more better reference resistor。i check the power 5v is ok.crystal is ok, if remove crystal or EPROM（AM27C512-150DC）, the display disappear，if remove eeprom 93lc66，always display garbled characters。because MCU and SRAM not easy to replace,so i thought maybe the FW in EPROM is broken, i want to refresh the ROM.but can't find a copy of this model, can someboby (i thought 1502 and 1502a have the same FW and pcb, so which one is ok)read a EPROM FW copy for me.thanks