GA-B150m-HD3 without memory power supply repair

Jijia GA-B150m-HD3 has no memory power supply and replaces MAQ8. After that, the bright machine fault is relieved!

Machine model: GA-B150m-HD3

Fault phenomenon: Click Switch, the fan will stop once,switch can be repeated

Maintenance process:

1、Test VCC, according to Intel timing, the first test memory is VCC, the first detection result is 0V.

2、Find the fault, repair around this fault, first detect the memory VCC chip mau210 pin chip z33b, in the Xunwei forum under a drawing run line.

3、First, measure the 3 pin en under mau2 working conditions, and find that no VCC is 0V. Then run down the line and find that the 4 pin to mau3 chip is a PG signal.

4、Mau3 chip is screen printed with 133a. This chip generates a 2.5V VCC. When the chip normally generates 2.5V VCC, the chip will send a PG signal from 4 pin to turn it on.Memory VCC chip mau2, measurement mau3 the 5th pin en for 0V, find the fault point, and then run down, to the maq7 maq8 maq9 three transistor.

5、It is found that the signal of maq8 2 pin control pin is available, but it can’t pull down 3 pin, which leads to that the 2 pin of maq7 is not pulled down, so the 2 pin of maq7 is always high level, so the 5 pin en of mau3 is pulled down. After the maq8 is replaced, the fault is removed and the maintenance is over!