Removing Smd Resistors And Capacitors From Pcb With A Soldering Iron; Removing Smd Ics From The Pcb; Removing Smd Ics With A Hot Air Smd Tool; Fitting Replacement Ics To The Pcb With A Soldering Iron - Cyrus 6 Service Manual

CYRUS 6 & 8 – Replacing SMT Components
Keep the soldering temperature as low as possible. 260ºC is recommended for SMD
rework. Most SMD components will withstand 260ºC for 5 to 10 seconds
Use tin/lead/silver solder which has a lower melting point (about 179ºC). Tin/lead/silver
solder paste or small gauge solder (26SWG) is recommended.
When using solder paste a pressure dispenser should be used to ensure the correct amount
of solder is applied to each pad.
Solder paste should not be used with direct heating methods as the solder between
component pins may not be melted.
If necessary, remove excess solder paste with solder braid.
Removing SMD resistors and capacitors from the PCB with a soldering iron
1. Fit the soldering iron with a tip large enough to bridge both ends of the component.
2. Place the soldering iron so that its flat tip will heat both ends of the component at once.
3. When the solder melts, remove the component with tweezers.
4. Allow the PCB to cool for a few minutes, removing any excess solder with desoldering braid.
Fitting replacement SMD resistors and capacitors to the PCB with a soldering iron
1. Apply a little flux to the connections.
2. Place the component in position.
3. Tin the soldering iron, bring the tip into contact with the PCB pad and flow solder to the
joint. Avoid bringing the soldering iron tip directly into contact with the component.

Removing SMD ICs from the PCB

1. Using fine tipped side cutters or tweezer cutters, snip all the leads of the device and remove
the IC body.
2. Desolder the leads from the PCB pads.
3. Clean up the PCB with solder braid.

Removing SMD ICs with a hot air SMD tool

1. Fit a suitable size tip for the IC being removed.
2. Heat the IC evenly until the solder melts.
3. Remove the IC with tweezers.

Fitting replacement ICs to the PCB with a soldering iron

1. Check that the pins of the IC are not distorted.
2. Using tweezers, position the IC over the footprint.
3. Check that all the IC pins are correctly aligned with the pads.
4. With a very fine tip soldering iron, solder in the pins at the corners of the IC.
5. Re-check the alignment and correct if necessary.
6. When the alignment is OK, solder the remaining pins of the IC to the PCB.
9 Jan 2006