7i76e all P1 pins are 5v high (except 18 ~25 which are 0v common as expected)

More
04 Sep 2020 18:07 - 04 Sep 2020 18:08 #180724 by PCW
If the P1 and P2 I/O pins don't work (and not just one but many) Its possible that you
damaged one or both bus switch chips (FST16211) on the 7I76E

You can check this by carefully measuring the voltage across C11 (for P1) and C68 (or P2)
If these are not close to 4V, the bus chips have been damaged by excessive
input voltage (less than -0.5V without a current limit or greater than 7V)
Last edit: 04 Sep 2020 18:08 by PCW.

Please Log in or Create an account to join the conversation.

More
04 Sep 2020 20:30 - 04 Sep 2020 20:31 #180749 by jhandel
both mid 40's mv so I'll chalk that up to a "learning" experience :-(

So given that the BOB was never plugged into P2 and P2 was never hit by anything but the 7i89 I am guessing the plugging of it in "hot" last night after the failed test of P1 killed P2...

And I guess my sainsmart cheap bob from 2016 that was collecting dust from a 2018 re-wiring of my CNC-Router might have been bad and somehow killed P1...

yah *jazz hands*

well I can save a whole bank of relays I added by switching to a 7i69ed because all the outputs on my machine sink voltage.. (all my inputs do too but I already have my pullup resistor trick so that is less important)

any suggestion on what to look at to see if the 7i89 is dead too?
Last edit: 04 Sep 2020 20:31 by jhandel.

Please Log in or Create an account to join the conversation.

More
04 Sep 2020 21:08 #180757 by PCW
Its possible that the 7I89 was damaged but can't be sure

The 7I76E is likely repairable by replacing the FST16211s

Please Log in or Create an account to join the conversation.

More
04 Sep 2020 21:56 #180768 by jhandel
likely true if I could do surface mount soldering.. but that would require a bit of tooling that might cost as much as a new card... I'll have to noodle on what to do now that I have gone and done fowled this up..

Please Log in or Create an account to join the conversation.

Moderators: PCWjmelson
Time to create page: 0.244 seconds
Powered by Kunena Forum