ViewSonic PJ452 Service Manual - Page 19

6. Service points 6-1 Lead free solder [CAUTION] This product uses lead free solder (unleaded) to help preserve the environment. Please read these instructions before attempting any soldering work. CAUTION Always wear safety glasses to prevent fumes or molten solder from getting into the eyes. Lead free solder can splatter at high temperatures (600˚C). Lead free solder indicator Printed circuit boards using lead free solder are engraved with an "F" or "LF". Properties of lead free solder The melting point of lead free solder is 40-50˚C higher than leaded solder. Servicing solder Solder with an alloy composition of Sn-3.0Ag-0.5Cu or Sn-0.7Cu is recommended. Although servicing with leaded solder is possible, there are a few precautions that have to be taken. (Not taking these precautions may cause the solder to not harden properly, and lead to consequent malfunctions.) Precautions when using leaded solder Remove all lead free solder from soldered joints when replacing components. If leaded solder should be added to existing lead free joints, mix in the leaded solder thoroughly after the lead free solder has been completely melted (do not apply the soldering iron without solder). Servicing soldering iron A soldering iron with a temperature setting capability (temperature control function) is recommended. The melting point of lead free solder is higher than leaded solder. Use a soldering iron that maintains a high stable temperature (large heat capacity), and that allows temperature adjustment according to the part being serviced, to avoid poor servicing performance. Recommended soldering iron: Soldering iron with temperature control function (temperature range: 320-450˚C) Recommended temperature range per part: Part Mounting (chips) on mounted PCB Mounting (chips) on empty PCB Chassis, metallic shield, etc. Soldering iron temperature 320˚C±30˚C 380˚C±30˚C 420˚C±30˚C The PWB assembly which has used lead free solder (1) PWB assembly MAIN (2) PWB assembly REMC (3) PWB assembly SW (4) POWER UNIT (BALLAST) (5) POWER UNIT (CIRCUIT) ViewSonic Corporation Confidential - Do Not Copy PJ452 16