Troubleshooting (Dv5Hh) - DeVilbiss Healthcare SleepCube nCPAP Device DV53 Instructions De Service

14. Troubleshooting
Symptom
The PAP does not recognize the
heater. (With the PAP blower
ON, the PAP display does not
indicate Heat:xxx on the bot-
tom line.)
Heater plate does not respond
to the PAP heat setting.
(With the PAP blower ON and
the heat setting at 1 or above,
the heater plate does not get
warm.)
Symptom
The PAP does not recognize a
known good DV5HH heater.
(With the PAP blower ON, the
PAP display does not indicate
Heat:xxx on the bottom line.)
Heater plate on a known good
DV5HH heater does not respond
to the PAP heat setting.
(With the PAP blower ON and
the heat setting at 1 or above,
the heater plate does not get
warm.)
Symptom
Excessive air leak
Water leak from the humidifi er
chamber.
HEATER
Connect the heater to a known good PAP device, if one is available. If PAP display still does
not recognize the heater, replace the heater.
If a known good PAP device is not available, remove the PAP from the heater and check
the thermistor for resistance. The thermistor pins are located in the connector and are the
ones closest to each other. See image below. The resistance should be 10 K ohms +/- 1%
at 25° C (77°F). If open or shorted, replace the heater. See Service instructions. Alternative-
ly: Replace the heater plate assembly, DV5H-607. If the resistance is in the correct range,
the issue is in the PAP device. Troubleshoot as indicated below.
Connect the heater to a known good PAP device, if one is available. If the heater still does
not respond to the heat setting, replace the heater.
If a known good PAP device is not available, connect the PAP, using the serial interface
cable DV54/DV53D-615, to a PC using a terminal program (such as Windows HyperTer-
minal, or equivalent) with Com settings 9600 baud, no parity, 8 data stop bits, 1 stop
bit, Flow Control set to none. Turn the PAP blower ON and increase the heat setting to
10 using the PAP keypad (UP key). In the terminal program, connect to the PAP device by
typing 'ri' followed by ENTER; then type 'Ht' followed by ENTER. Repeat the 'Ht' – ENTER
sequence every 2-3 minutes and verify that the returned value increases. If the value in-
creases, the system is operating normally. If the value does not increase, remove the PAP
device from heater and measure the heater resistance. The heater terminals are the ones
diagonal to each other on the connector.
thermistor terminals
The resistance should be between 180 to 220 ohms; if not replace the heater. See Service
instructions. Alternatively: Replace the heater plate assembly, DV5H-607. If the resistance
is in the correct range, the issue is in the PAP device. Troubleshoot as indicated below.
PAP
Check the wire harness on the PAP / heater connector; repair or replace, if needed. If
the wire harness and connections are correct, replace the control PC board. See Service
Instructions.
Check the wire harness on the PAP / heater connector; repair or replace, if needed. If
the wire harness and connections are correct, replace the control PC board. See Service
Instructions.
MANIFOLD and O-RING
Remove the humidifi er chamber. Inspect the manifold in the heater base and replace, if
torn or worn. Inspect the O-Ring in the humidifi er chamber and replace, if worn or missing.
Remove the humidifi er chamber. Inspect the chamber for cracks in the plastic or water leak-
ing from the heat transfer plate. If cracks or transfer plate leaks are found, replace the water
chamber. Inspect the O-Ring in the humidifi er chamber and replace, if worn or missing.
Action
heater terminals
Action
Action
EN
DV5HH
25
LT-2026