Mitsubishi MU17NN User Manual

36
Check of indoor electronic control P.C. board
C
The unit doesn’t operate with
the remote controller.
Also, the operation indicator
doesn’t light up by pressing the
emergency ON/OFF switch.
Replace fuse.
1.Pull out power supply
cord.
2.Measure resistance
between CN201
on electronic con-
trol P.C. board and
on the terminal block
with a tester.
Trouble of indoor electronic con-
trol P.C. board.
Is there resistance
(Approx.0Ω)
Trouble of fuse(F12)
Replace varistor.
1
N
Yes
No
Yes
Check both “parts side”and “pattern
side
w
of indoor electronic control P.C.
board visually
No
Be sure to check both fuse
and varistor in any case.
Is varistor(NR11)burnt?
Yes
Is fuse(F11)blown?
Check of outdoor unit
D
Compressor and outdoor fan do not operate.(Only indoor fan operates.)
Check resistance to terminal block of outdoor unit. Is
there 115V(MS09NW), 208/230V(MS12/15/17NN) to
terminal block between - (MS09NW), -
(MS12/15/17NN)?
Press Emergency operation switch.
3-minute time delay works.
Test mode operates for 30 minutes.
Start
Check voltage to terminal block of indoor unit. Is there
12V to terminal block between - ?
Check the outdoor fan motor, compressor, relay, and
wiring.
Check the indoor, outdoor connection and
respective power supply.
Replace indoor electronic control P.C.
board.
L1
L2
L1
N
2
1
No
No
No
No
11
33
L1
N
Terminal
block
CN201
No
OB192--2.qxp 23/6/97 11:50 PM Page 36

Mitsubishi MU17NN Specifications

General

Brand	Mitsubishi
Model	MU17NN
Category	Air Conditioner
Language	English