Tweco 151 with SL100SV - Manual (Page 99)

Manual 0-4691 5-31 SERVICE
5
C. Logic PC Board Replacement
Follow the antistatic instructions provided with the replacement part. The Logic PC Board connects to the Main PC Board
through an extender board perpendicular to both boards.
1. Remove the power supply cover per Section 5.09-A.
2. Remove the bolts in each corner of the Logic PC Board.
3. Detach the Logic PC Board and the extender board from the Main Power PC Board. Detach the extender board from the
Logic Board.
4. Install the replacement Logic PC Board by reversing the above steps. The pins on the right edge of the Logic PC Board
must fully engage the sockets on the edge of the extender board. The extender board must fully engage sockets on the
Main Power PC Board.
D. Input Diode Bridge Replacement
Follow the antistatic instructions provided with the replacement part.
NOTE
Follow the electrostatic discharge instructions provided with the replacement component to prevent damage to
the component.
Thermal pads, heatsinks, and the large flat surface on the back of diodes and IGBTs must be kept clean. Diodes and
IGBTs must not be bent or allowed to pick up any foreign material. A very clean installation between the module
and the heatsink or chassis is essential for proper operation.
1. Remove the power supply cover per Section 5.09-A.
2. Turn the Power Supply onto its side.
3. Locate the Input Diode mounted to the center chassis, to the left of the Main Power PC Board. Refer to Appendix pages
for location and position.
4. Label, then remove all wire connections to the diode bridge being replaced. Note the routing of wires. Ensure that the
wires are put back in the same place when installing the replacement bridge. Keep the hardware for re-use.
5. Remove screws securing the bridge to the heatsink and remove the bridge from the Power Supply.
6. Use isopropyl alcohol and a clean rag to clean the chassis area behind the component being replaced. Clean the large flat
surface on the back of the replacement component. Do not scratch or abrade the surface.