MBP Up/Down doesn't work, Precise indicator lit when push, Standard indicator not lit when push. Med wrench Valley Lab 4B service manual is different from this 4B. The bipolar control board, bipolar output board, CPU board are not individual board, instead all circuits are mixed on parent board. The info in the back: Force 4B, Dash -20, S/N P9B1520B. Any other version of Valley Lab 4B Service Manual?
