HIKVISION DS7208HVI-ST Product/Maintenance Manual page 16

⑤.RS485 Failure
Step 1: the first to exclude thermistors JK250 (RPT1/2)
Step 2: measurement TVS tube B03NC (BA2/7) impedance, or replacement
Step 3: measurement 6L184 6and 7 feet chip difference voltage (normal close
to 5 V), or replacement
⑥. Internet Links
Network light and network data transmission light are flashing

Step 1: first measurement RTL8201 chip PIN 36 input voltage 3.3V is normal, or
to measure WCX (FBN1) impedance, or replacement
Both network light and network data transmission light not bright

Step one: first measurement 25 M (Y3) crystal, or replacement
Step two: replace RTL8201
Both network light and network data transmission light are nomal

Step one: first replace RTL8201, and then ruled out MS10232, BV03C
（TVS32/17）
⑦.SATA Hard Dish Fault
Step one: first measurement BD9329 (U1) PIN 3 power output voltage wheather 5V or short
circuit, or replacement
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 75Ω 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