Problem about 1769-L31

Dear All members

I have problem about CPU CompactLogix 1769-L31 as follows;

Step 1. I connect this CPU 1769-L31 with 1769-PA2 and 1769-ECR.
Step 2. Later, I power ON to 1769-PA2
But The green LED near the lamp symbol (LED Power)
on 1769-PA2 will turn OFF immediately !

1769-PA2 Not working !!

Step 3. Later, I change the another CPU to connect with this 1769-PA2
The 1769-PA2 still working properly.

I suppose that there is the problem in 1769-L31, but I don't know
what is a problem ? and solution ?

anyone please tell me how to fix this problem.

Thank all

You could inspect the pins of the backplane connector to see if anything is obviously wrong but it sounds like its now a door stop.

To jstolaruk

I connect this CPU with 1769-PA2 properly.
This CPU had worked properly until the last month (May 2018), It has failed !!

When I power ON to 1769-PA2, There are no LED lamp show on both CPU
and 1769-PA2. ( I guess 1769-PA2 shutdown itself.)

But I use another CPU connect with the same 1769-PA2, They work properly.

I never encounter this problem.

Sounds like whatever has failed in the cpu crowbars the power supply. There is no procedure or instructions available to repair a cpu that I am aware of.