Alpine MRV-F300 board problem

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Got what might be an easy question. I have the Alpine MRV-F300 that was showing short on the rectifier D9902 (common cathode rectifier). I took it out of the board, and tested, it tested fine. I checked the board and the board had a short between the legs. But i can find no where that those legs would be shorted. Is this a multi layer board (more than the top and bottom layers)? I couldn't find where all the traces go, leading me to think there is at least a 3rd layer sandwiched in there. Any help is great, thanks!
 
You can use a backlight from a bright light to see inner layers.

In the MRP-M1000, I've had similar problems with the outputs. I just let it run through a limiter and after a while, I heard what sounded like a fuse blowing and the short was open.

Side note... The service manual doesn't even show all of the layers.
 
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