Checking Method For Pcba Of 7~12Hp - Hitachi mini-HNRQ1 Series Service Manual

3.2 Checking Method for PCBA of 7~12HP

(1) Checking Method of Outdoor Unit PCB
Check the power circuit on O.U.PCB in following procedures. Refer to the figure on next page about the
positions of LEDs, fuses, and check points. Refer check points by a circuit tester and judgment value as well.
CAUTION
!
● Pay attention to an electric shock when the voltage is measured by a circuit tester.
● Do not contact the test lead to unspecified check points when measuring by circuit tester. It may cause
failure of terminal and circuit tester.
● When the voltage is measured by a circuit tester, the range should be set within the DC voltage
measurement. If the setting is not correct, it may cause failure of O.U.PCB and circuit tester.
Turn ON outdoor unit
LED4 (Red) is turned ON.
Yes
DC5V-Driver is applied
between Vcc05 and GND.*1)
Yes
DC5V-Driver system is
normal.
Yes
DC12V is applied between
Vcc13 and GND.*1)
Yes
DC12V system is normal.
Yes
Check is completed
Power circuit is normal.
*1) The following table shows the check points and the normal range of voltage in case that the voltage on
O.U.PCB is measured by a circuit tester. The setting of circuit tester shall be set within the DC voltage
measurement range when the following voltages are measured.
(+) Side of Tester
5V
12V
No
No
No
Check Point
(-) Side of Tester
GND
Is fuse EFR1
blown out?
No
AC Power is lower than
90% of the rated voltage
No
10.5VDC ~ 13.5VDC
109
TROUBLESHOOTING
Yes
Change the fuse
Yes
Check the voltage
Failure of AC Power
Circuit
Normal Range (V)
4.8VDC ~ 5.1VDC