
4
44
4
F
ault Finding
9. Fault Finding
1. The LCD display may show marks and symbols when the unit is not turned on. This is
caused by static charge on the display and will disappear after a short while.
2. If the marks do not disappear, then the display could be stressed or cracked.
If this is the case fit a new display.
9.1 LCD - Marks On Display
1. Check for output at the headset socket. If present, check speaker and headset socket.
2. Check for signal on input to volume control potentiometer and output to headset socket.
3. If no fault is found with the headset socket, volume control or speaker fit a new PCB.
N.B.
Ste
ere
eo
o o
output iis o
onlly a
ava
aiilla
ab
blle
e wiith
h th
he
e SD2
2-P
P, MD2
2-P
P o
or RD2
2 wiith
h h
he
ea
ad
dph
ho
one
es
c
co
onne
ec
cte
ed
d.
9.2 No Sound
1. Check for supply voltage across the on/off switch, if supply is not present it may be a
broken track, battery connector or a flat battery.
9.3 Unit Dead
1. Check integrity and continuity of sockets.
2. Refer to user manual to ensure that the Dopplex is in the correct mode.
9.4 No Output From Sockets
1. Refer to user manual to ensure that correct technique is used.
9.5 Poor Heart Rate Tracking
3. Apply firm pressure radially around the outside edge of the faceplate using thumb and
forefinger. Listen for clicking, instability or change in background noise level.
4. If any of these effects are heard, reject the probe for head replacement.
9.6 Poor Sensitivity, Crackling
1. Check retractile cable with either known good PPG probe or vascular probe.
If fault still persists, consult Huntleigh Healthcare Ltd Service Department.
9.7 PPG not locking on
CAUTION:
Und
de
er no
o c
ciirc
cumsta
anc
ce
es sh
ho
oulld
d pre
essure
e b
be
e a
applliie
ed
d d
diire
ec
ctlly to
o
th
he
e fro
ont fa
ac
ce
e o
of th
he
e pro
ob
be
e h
he
ea
ad
d o
or PPG se
enso
or.
Test for cracked crystals as follows:
1. Connect transducer to control unit (not applicable to D920-P, D930-P, FD1-P or FD3-P).
2. Set audio volume to maximum. Ensure that faceplate is clean, dry and unmarked.