⑧
. Clock Fault
Step one: the first to rule out the battery (normal voltage 3.3 V), and then ruled
out 8563 T, 32768 HZ, diodes
⑨
.VGA Output Color Devation
Step 1: measuring 75
Ω
resistance (RG4/5/6), or replacement
Step 2: measurement BAV99 (Q3/ 7/8) PIN 3 impendance to GND, or
replacement
Step 3: rule out 6303 chip
⑩
.USB Fault
Step one: measurement SESR05 (QA1 or QA2) 2, 3 feet voltage difference
value (normal voltage difference about 3.05 V), as well as the impedance to the
GND, or replacement
Note: SESR05 (QA1 or QA2),front and after USB interface is independent of
each other
SESR05
（
QA2
）
SESR05
（
QA1
）
