Unfortunately it sounds like an internal problem. Resoldering the terminals or board is a daunting task. Even the high end stuff is put together sometimes pretty shoddy on the inside. Trying to fix one thing you may break another. But if its past warranty it wouldnt hurt to pop the hood and have a look. Wish I was local and I could stop by to check it out for you. You may check to see if theres a local repair for HK nearby.
Otherwise you may just want to upgrade.