I am saddled with a perfect 8405A with one defective probe. Swapping the
sampling board between probe tips shows that the fault follows the
board. The measured voltages are correct for the good board, but not for
the failing board. The diodes check out OK for F/B ratio, leaving not
much else to change except the FET.
Can anyone on the list suggest a suitable replacement part or
troubleshooting strategy?
Arthur Shulman VE3ZV
