MJLJ V4 kit assembly guide

Revision as of 04:16, 11 June 2008 by Brentp (talk | contribs) (+parts table)

Precautions

Surface mount Components

The soldering portion of this kit was NOT designed for beginners!

The Megajolt Lite Jr. makes extensive use of surface mount components. 
Hand-soldering SMT components requires advanced soldering skills and a steady hand. 
Individual parts are tiny, and are therefore easy to overheat and damage.

If you are not comfortable assembling this kit after reviewing the instructions, we recommend you purchase a ready-made and tested unit from our online store, offered at a reasonable price.

Before you Begin

Familiarize

Read the instructions completely before soldering your first component.

Do not lose parts

  • Leave the parts in their bags and protective tape: Remove them just before soldering.
  • Tiny flying parts: Be careful when extracting the parts from the tape- they can go flying if the protective tape is removed too quickly. Also, ensure you have a good grip on the part with your tweezers- a missed tweezer grab can send the part flying.
  • Work surfaces and floor: Work in a clean and open area, preferably with hard floors: if a part falls off the bench or flies away from a missed tweezer grab, it will be easier to find.

Lighting

Use lots of good lighting- best is to use bright overhead lights combined with an illuminated magnifying glass.

Note part orientation

Some components, such as diodes and capacitors are marked with a band indicating their orientation. The markings on these components can be faint- especially with the diodes. Be sure to positively identify the component orientation before soldering- good lighting will help this tremendously.

Do not overheat

Small parts are easy to damage- use minimal heat required for soldering components. It is essential a recommended low wattage, fine-tipped soldering iron be used for assembly.

Assembling the kit

Tools you will need

Below are the essential tools you'll need for this project:

Essential smt solder tools.jpg
Illuminated magnifying glass.jpg
The essential tools for SMT work

  • A fine-tipped, low wattage soldering iron is necessary for precision work.
  • Probably the best tool - a cross-action set of tweezers. This tool is normally closed, allowing you to hold parts with a relaxed grip and reduced tremors.
  • Solder wick. Too much solder and you'll create ugly blobs and solder spikes. use this to clean up your joints by drawing away excess solder.
  • A magnifying glass, preferably illuminated, is useful for identifying package markings and inspecting solder joints.

Parts Inventory

Core Parts
Part Type Value Photo
R1,R7 Resistor 100 ohms 1206 chip resistor.jpg
R2,R8 Resistor 1K 1206 chip resistor.jpg
R5,R6 Resistor 2.2K 1206 chip resistor.jpg
R9 Resistor 680 ohm 1206 chip resistor.jpg
D6,D7 Schottky Diode SOD-123.jpg
C3,C4,C5,C6,C7,C10 Capacitor 0.1uF 1206 chip capacitor.jpg
C15 Capacitor 0.001uF 1206 chip capacitor.jpg
C16 Capacitor 0.22uF 1206 chip capacitor.jpg
C1 Capacitor 33uF 20v electrolytic Radial electrolytic capacitor.jpg
C2 Capacitor 33uF 35v tantalum D-case tantalum tan.jpg
D1,D2,D3 Diode 1A 400v rectifier SMA case diode.jpg
D4 Diode 12V Zener SOD-123.jpg
LED1 LED Right angle LED, green LED right angle green.jpg
U1 Integrated Circuit MJLJ V4 Processor Freescale MC908QB8 File:MC908QB8.jpg
IC1 Integrated Circuit ULN2003 Transistor Array File:ULN2003.jpg
U2 Integrated Circuit MAX232A Transceiver (or equivalent) File:MAX232a.jpg
U3 Integrated Circuit LM2937-5.0 voltage Regulator SOT-223.jpg
QG1 Oscillator 16MHz oscillator Oscillator half can.jpg
IC1,U1 Sockets 16 Pin DIP Socket File:PDIP-16 socket.jpg
X1 Connector RJ-11 jack File:RJ11 jack.jpg
X2 Connector Molex Right angle, 16 position File:Molex minifit right angle pcb.jpg
TPS Option
Part Type Value Photo
R3 Resistor 1K 1206 chip resistor.jpg
C11 Capacitor 0.1uF 1206 chip capacitor.jpg
C12 Capacitor 0.001uF 1206 chip capacitor.jpg
C13 Capacitor 0.22uF 1206 chip capacitor.jpg
C14 Capacitor 15uf D-case tantalum grey.jpg
D5 Diode Schottky Diode SOD-123.jpg
L1 Inductor 1uH 1210 smt inductor.jpg
MAP Sensor Option
Part Type Value Photo
R4 Resistor 270 ohm 1206 chip resistor.jpg
C8,C9 Capacitor 0.1uF 1206 chip capacitor.jpg
PS1 Sensor MPX4250ap File:MPX4250ap.jpg


Surface Mount Parts

Power supply Circuit

Components

Testing Voltages

Main Circuit

Components

Testing Voltages

Through Hole Parts

Installing ICs

Inspection