Fresenius Medical Care 2008K2 Troubleshooting Manual page 577

b) Per the Figure below, open the power supply. TWO (2) checks:
CHECK #1: Inspect the entire length of the 24V Power Harness. If burning or damage is
located this may be the problem!
CHECK #2: Inspect the surface of and all wires attached to the Power Control Board. If burning
or damage is located this may be the problem!
Figure 109 – Power Control Board / 24V Power Harness / IC4
c) Locate IC4 on the Power Control board..
d) IC4 (see Figure 109 above) is socketed and can be removed without desoldering! CAUTION!
Being careful NOT to install it upside down swap in a known good IC4 chip BEFORE continuing
to procedure number WD- 1.0.4 (page 574).
2008K/K2 Troubleshooting Guide
P/N 507298 Rev. H
Page 573