On each water circuit in side the service cap, there are 4 soldering stems which two of them are inside blue nylon insulator and other two are connected to service tray. Each stem has two soldering spots. See attachment pictures for detail location. I sprayed 15 psi helium on each soldering spots on stems  for 20second on each circuit. I sprayed tons of helium inside each blue nylon.No any leak has been found during the check. The leak detector base leak rate:0.0 XE-9 atm.cc/sec, base pressure:0.0X E-4 torr. The circuit which I checked are :TA+, Ta-, Tube+, Tube-, PQ (coil 2), RU( coil1), EE, MSP, GE. The HS and window circuit are opened at this moment so they can not be checked.