Daikin 2MKS40FV1B, Service Manual

Page: 164 / 206

SiEN12-710A Check
Service Diagnosis 153
5.1.12 Power Transistor Check
Check No.13 " Checking the power transistor
! Never touch any live parts for at least 10 minutes after turning off the circuit breaker.
! If unavoidably necessary to touch a live part, make sure the power transistor's supply
voltage is below 50 V using the tester.
! For the UVW, make measurements at the Faston terminal on the PCB or the relay
connector.
5.1.13 Main Circuit Electrolytic Capacitor Check
Check No.14
" Checking the main circuit electrolytic capacitor
! Never touch any live parts for at least 10 minutes after turning off the circuit breaker.
! If unavoidably necessary to touch a live part, make sure there is no DC voltage using the
tester.
! Check the continuity with the tester. Reverse the pins and make sure there is continuity.
Tester's negative terminal Power transistor
(+)
UVW
Power transistor
(–)
UVW
Tester's positive terminal UVW
Power transistor
(+)
UVW
Power transistor
(–)
Normal resistance Several kohms to several Mohms
Abnormal resistance 0 or
∞
Keep the tester in the
resistance measuring range.
When the pointer swings,
it means the capacitor
functions.
If the pointer does not swing at all,
or if it swings all the way but does
not return, it means the capacitor
malfunction.