I am Haroon and i have not too much experience in PCB repairing therefore can any one explain that how can i start to diagnose a problem in any type of PCB . I mean that if a circuit board consist of RAM , EEPROM , lathes , logic gates , resistors , capacitors , transistors and operational amplifires and i dont have schematic and description of pcb than which components i have to check first.

Best Regards

Haroon

 

All you can do is visually check the board and look for components that look damaged. But even if you replace the damaged parts if you don't know how they were damaged then you replacements may not fix the problem.

Otherwise you question is far to vague to really comment much further.

 

Like pwdixon said, look at things first for any obvious problems. Resistors may burn or components may melt, smoke or overheat while the circuit is running too.

After that you should check active devices like transistors and chips, but if you can tell us how the circuit is behaving if it is doing anything at all, it might help limit the places to look. Is it completely dead or just wounded?

 

Thank you for your replies , actually i am working in an inverter that converts single phase into three phase power. All IGBTs and their base resistors and transistors are OK but gate to source voltages are completely zero therefore can you suggest me that which section of that inverter may be suspected . I meant that is it controller problem ?