Basic tips for circuit board repair
A common circuit board, the circuit is combined into ten million,
The appearance of the component often changes, and the character recognition is the key
Resistance and capacitance are the most common, and damage is also very common
The resistance value is easy to change, and the leakage capacitance of the capacitor is also leaking.
Inductive transformer is a coil
Diode and triode, measure the positive and negative of the PN junction
MOS tube and thyristor, trigger test is the key
The above are discrete parts, integrated circuits for many years
Analog devices have op amps, virtual short and virtual ends to judge
The optocoupler isolates the front and rear stages, and the damage is tens of millions
Digital devices are often seen, in front of 40 and 74
There is also an analog-to-digital converter, which is very laborious to test
Don't forget ROM and CPLD, programming depends on programmer
CPU, microcontroller, timing judgment logic instrument
Various sensors, ranking first in damage probability