Isolate 24 Volt Switch - Fresenius Medical Care 2008T Troubleshooting Manual

P- 2.0.6 ISOLATE 24 VOLT SWITCH
Turn the machine OFF!
a)
b) Per the Figure previuos page,
pin 1
'X2' connector,
c) Looking for pin 1 to fall below 1.0 volts AT LEAST ONE (1) TIME,
FROM THE METER
d) TWO (2) possible scenarios:
1) IF (and ONLY if) pin 1 REMAINED ALWAYS more than 10.0 volts i.e. NEVER fell to less than
1.0 volt. Repeat procedure P- 2.0.6. If pin 1 STILL NEVER drops to less than 1.0 volt see
procedure number
2) IF, AT LEAST ONCE, pin 1 DID FALL to less than 1.0 volts: If System Initialization DOES NOT
reach 100%, TWO (2) possibilities: 1) Bad 24 volt switch (IC4)* on the Power Control Board (inside
the power supply) OR; 2) Bad thermal (BROWN) fuse S18*
* To LOCATE IC4 and fuse S18 refer to
HOLD
the meter lead on the solder (rear) side of Power Logic Board's
(bottom row, first pin from the REAR of the machine).
, turn the machine ON (fan running) and watch it for thirty (30) seconds!
P- 2.0.7 (page 704).
LEFT BLANK INTENTIONALLY
2008T Troubleshooting Guide
P/N 490292 Rev. A
WITHOUT LOOKING AWAY
Figure 132, (page 710)
Page 703