820-00164-A (intermittent shutdown) Solved. Just wanted to share.

I had something I have never seen before and don't know why it failed. I wanted to share.

This board has a history of being intermittent. Came in for intermittent shutdown. I did notice some intermittent green light so I went and looked at PP3V42_G3H Noticed that I had 3.1v. After checking resistance to ground on L7905 I decided there is not a short or excessive load on this supply. Usually if I see a low voltage I jump to both sides of L7905 and if they are not the same I can see that the supply is heavily loaded. In this case high resistance to ground and no heavy load. After checking supply to U7090 I determined that it was getting great power. I figured I either have a cap here or a bad U7090. I decided to go for the U7090. U7090 fixed my problem Output went to a solid 3.42v

Just wondered if anyone has seen this in a PP3V42 supply before?
 
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