What phono preamp board is in a NAD 7150 Receiver ?

Im getting a very deep popping noise out of one channel in phono, almost like a crackling noise. Sometimes the channel is fine, then it loses clarity and volume. When I wiggle the board it happens too.
There is a 3150 phono preamp board for a NAD on ebay, looks the same...just looking for advise. Like I said if I move the board just right it will work fine.
Can I just bypass the phono stage with an external phono preamp?