ViewSonic PJ650, Service Manual

Page: 17 / 62

16
PJ650
17
PJ650 (C3XM4)
PWB assembly DRIVE
PWB assembly INPUT
PWB assembly SENSOR
PWB assembly SWITCH
PWB assembly REMOTE
The PWB assembly which has used lead free solder
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.
Lead free solder indicator
Printed circuit boards using lead free solder are engraved with an "F."
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 Soldering iron temperature
Mounting (chips) on mounted PCB 320˚C±30˚C
Mounting (chips) on empty PCB 380˚C±30˚C
Chassis, metallic shield, etc. 420˚C±30˚C
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).
ViewSonic Corporation PJ650