Ampeg BA-112v2 not silent with phones?

I have a Ampeg BA-112v2 and it makes some sound even with headphones plugged in. I took out the board and did a few experiments. It seems to bleed the aux-in sound a little too. I am not talking very loud I’m just talking about recognizable thumping while I’m practicing. I took the Jack out and doesn’t seem to be much I can see that’s wrong but I’m having a little bit of trouble finding a new headphone jack in a timely fashion. I found the entire board for about $47. My question is is this unusual or a common thing. I called an amp repair place this morning and He said that I should check to make sure that that’s not abnormal before I go spending money so here’s my question thanks

 

Called Ampeg Customer Service today. Great Convo. The guy said he actually had my amp there and asked for me to hold a few minutes so he could try what I was talking about. He came back and said it shouldn’t be doing that so my choice was to either deal with it or get a new Preamp Circuit Board (easy drop in direct replacement) so that’s what i’ll do. Very friendly, one of the best interactions I’ve had with phone customer service.

 

Update I did some research and found the right jack and replaced it. Same problem. So I ordered the $47 board. I called my local Ampeg authorizes service guy. He said to buy the board because he wouldn’t be able to fix it for that price. Waiting for it to arrive they said could be a couple of weeks.