Phenomenon: The power-on screen flashes 0.00 or the screen does not light at all;
The fault occurs indefinitely, and the normal maintenance time is not fixed. Heat treatment will make its function temporarily normal.
The fault can be solved by setting the I/O port high. But the power consumption is increased;
Repeated reset phenomenon occurs. Through continuous testing, the P7.6 port line is configured to output high level, then no reset occurs and the function is normal.
Crystal oscillator circuit
P7.6 port circuit
Reset circuit
