Troubleshoot Electronic Circuit (Lesson 1) - - - VMI

Salam,

Lesson 1: VMI (Visual Mechanical Inspection)



What is the purpose doing VMI?
To find out physical defect on electronic circuit.

Why?
Most of the functional failure can cause from hardware failure and software failure. The hardware failure more easier to identified if compare with software failure.

How to do VMI?
By doing physical inspection using microscope (30X zoom) to identified the physical defect such as Expose Copper, Crack, Solder Bridging, Solder Join, Melt, Explode, Burn, Shorted and others.

Why need microscope?
It much easier to inspect defect on SMD's Components(Surface Mounted Device). Naked eye difficult to recognize failure defect on extra small components.

all this remind me to this proverb: "Jika tiada angin masakan pokok bergoyang". Hope you get what i meant?

How you read schematic diagram without knowing the function of the circuit? (electronic)

Salam,

Many things need to catch up in past two weeks. Eight cases handled from various customer basically more on electronics's components (SMD) and Printed Circuit Board Assembly (PCBA). Alhamdulillah my senior assist me a lots. He told "we are like detective", because every time found somethings need to take evidence (picture/diagnostic/functional result). Jom! let learns together..



How you read schematic diagram without knowing the function of the circuit? (electronic)

I had search on google and found something goods from expert who have working experience more than 20 years on electronics.. :) Below is the answer:-

"I've been an electronics tech for almost 20 years now. Learning to read schematics takes time and is a crucial part of troubleshooting. There's people who have been in the field for years and are still not proficient at reading prints. Of course being able to read the prints does you no good if you don't understand electricity and electronics. But the first step to reading prints is learning the symbols.

Here's a VERY good free intro to schematic symbols. It even has a little matching excersice at the end. Start here:

http://www.wisc-online.com <--register free

Once you've completed the excersice, you can go to this link where they have a pretty good reference chart of component symbols and their function.

http://www.kpsec.freeuk.com/symbol.htm

These will get you started.

There are many different kinds of diagrams (1-line, 3-line, Elevation, P&ID, Instrument Loop, Logic Flow, Schematic, Mechanical Integrity, Electrical, Conduit plan, Wire Schedule, etc, etc). Learning how to read all of them proficiently is quite a task and can't be explained here."