PinOut of DEC F11 Chips in a Professional 350

[Rob Jarratt]

As I mentioned in an earlier thread, I am trying to repair a DEC
Professional 350 system board. I think I know the pinout of the F11 chips
from a KDF11-A printset, can anyone confirm that pin 23 of the DIL package
is the RESET signal? If that is correct then it is oscillating and resetting
the machine constantly. I am trying to trace the source, but it seems to go
through quite a few chips and I haven't yet traced its source.

 

The chips where I believe the RESET is oscillating on pin 23 have been
labelled E151 and E152 in the following photo:
https://rjarratt.files.wordpress.com/2018/10/system-board-labelled.jpg But I
am not really sure if I have identified them and the pin correctly.

 

Thanks

 

Rob