7i76E: Damaged Line Driver U12 & U19 (74ACT540DTR2G / 74ACT541DTR2G)

Hello,
I found out that i damaged my 7i76E dir/step line driver U12 and U19. (see picture)
The damage happend after i had to fix 2 wires inside my control panel that is mounted to my Lathe Z Axis and it seems the 24V wires got squeezed after i mounted it back.

Actually i am not 100% sure if both are damaged and my actual question is if its possible that only the 74ACT540DTR2G (U12) got damaged, but not the 74ACT541DTR2G (U19?
U12 is visible damaged, but not U19.
I ordered already the 74ACT541DTR2G driver, because its not available anywhere, but on aliexpress and the shipping will take for sure at least 2 weeks, so i thought i better order it now.
In case its possible that only the U12 driver got damaged, then i will order it and replace it without the U19 driver, but if its pretty safe that also the U19 driver got damaged then i will wait and let both replace at ones.

Thanks in advance.
 

You can often tell is the driver is OK by simple checking the
unconnected step/dir output voltages. They should be very close to 5V or 0V
When LinuxCNC is not running, the + pins should be high, the - pins should be
low, and anything else indicates a bad chip.

Hello PCW, thanks for your reply.

I was just at the workshop to do the measurements, but i believe i measured wrongly, but still the results might be telling:

Voltmeter Plus wire to +5V on the terminal of the 7i76e
Voltmeter Minus wire to Dir+ and Step+
Result: about 4.8V (but i also put the minus wire on the Dir- and Step- and got about the same voltage)

Voltmeter Minus wire to GND on the terminal of the 7i76e
Voltmeter Plus wire to Dir- and Step-
Result: below 0.2V (but i also put the plus wire on the Dir+ and Step+ and got about the same voltage)

Also i measured between +5V and GND on the step/dir terminal:
Result: 5.00 V, almost exactly.

Edit:
Dir+    to   Dir-  :   -0.021 V
Step+   to   Step-  : -0.021 V

Well, the last reading indicates a problem.

You should always have 5V (or -5V) when measuring
between Step+ and Step- or Dir+ and Dir-

Alright, thank you PCW.

I will wait for both Line Driver and replace them at same time.