Thank you Askild. I will order the right parts. I replaced the 28C16 in two analyzers exactly as described by HP (life!) without any issues or error messages. After debugging one and finding the RF flatness calibration constants were all gone. Looks scary indeed but it seems to work without problem.
In the meantime I bought an Eprom programmer (kindly advised by one of the forum members), so now I can also follow your way.
I consider it a good idea to (gradually) replace all the Eproms in 25+ year old equipment as a matter of preventive maintenance. Eproms can be obtained pretty cheap these days, even from trusted sources.....
Thanks again, kind regards,
Harke
On Thursday, February 28, 2019, 10:29:21 PM GMT+1, Askild <megafluffy@...> wrote:
Hi
Yes, its 27C512 if you have the 6 eprom version. I think there is newer version of the cpu board that only have 4 eproms, so check.
It is also advised to replace the eeprom, if its the original 2816, replace with 28C16.
The service manual has a procedure to change the eeprom with power on, but I did not use that procedure when I upgraded firmware and replaced the eeprom, I just used my eprom programmer to read out the eeprom and 'burn' it on the new one.
