Fresenius Medical Care 2008K Troubleshooting Manual page 128

T- 7.3.0 TROUBLESHOOT TEMP DISPLAY PROBLEM
Seven possibilities: 1) Bad test board; 2) Bad actuator board; 3) Bad sensor cable*; 4) Bad sensor board;
5) Bad function board; 6) Bad distribution board; 7) Bad motherboard.
* The cable can be checked for continuity. NOTE that one (1) NTC #3 connection will be checked and
proceed to page 228,
T- 8.0.0 CHECK NTC #2
This procedure checks NTC #2 resistance ( ). An accurate thermometer is required. If not available or, if
preferable, replace NTC #2 (see
T- 7.0.2 (page 122).
a) IMPORTANT! Turn the machine off.
b) Referring to Figure 54
"CON-NTC"). This is NTC #2.
c) Using a flashlight, check the vacant position for 'white'
corrosion or damaged male pins that may cause false signals.
If damage is located this may be the problem!
d) Referring to Figure
chamber to expose its 'probe end'.
e) Clean the 'probe end' with paper towel. Do not touch it from
this point forward to avoid fouling it!
f) VERY CAREFULLY (very thin wires) open NTC #2's
female distribution board connector.
g) Check for rust, corrosion, or broken solder connections.
Replace the NTC if rust or corrosion is located.
h) Touch your ohm meter's leads together and subtract its resistance ( )
reading from subsequent resistance readings.
i) Referring to the Figure (above, right), CLIP or HOLD FIRMLY the
meter leads between the green and white wires.
j) Fill a Styrofoam cup with water between 36 and 38
measured with an accurate industrial grade thermometer.
k) Referring to the Figure (right),drop NTC 2's probe end into the cup
and allow 30 seconds for stabilization.
SECTION 17 - CHECKING THE SENSOR BOARD
Figure 54, page 126) with a known good then return to procedure number
(page 126), unplug the connector from the
Figure 54 – Hydraulics Rear View – NTC #2
54, remove NTC #2 from the hydro
Fresenius 2008K Troubleshooting Guide
P/N 507298 Rev. B (Draft 1)
CABLE.
st
1
position from the left, (labeled
o
C as
Section 4 – Temperature Problems
Page 126