Choose Your Product
No Product SelectedSelect Product
System board, microprocessor, and heat sink installation - ThinkCentre A50, S50

These instructions are also available in movie format:

Attention: If the computer has been turned off for a long period of time the thermal grease between the microprocessor heat sink and the microprocessor might not allow them to be separated easily. In this case turn on the computer for a few minutes to soften the grease.

  1. Turn off the computer and disconnect the power cord from the electrical outlet.
  2. Disconnect all cables attached to the computer. This includes power cords, input/output (I/O) cables, and any other cables that are connected to the computer.
  3. Open the cover. See "Cover removal ".
  4. While holding the left rear of the computer chassis down, pull upward on the handle provided, to remove the PCI riser card assembly along with any adapters.

remove PCI riser assembly

  1. Remove the plastic cover from the microprocessor heat sink '1'.
  2. Completely loosen the screw in each of the two clamps '2' that secure the microprocessor heat sink. Tilt the two clamps away from the heat sink.

removing the heat sink

  1. Carefully twist the heat sink to break the grease seal to the microprocessor, then remove the heat sink.
  2. Place the heat sink on a clean work surface.
  3. See figure below. Take notice of the orientation of the beveled corner on the microprocessor '2'. This is important when reinstalling the microprocessor on the system board.

removing the processor

  1. Remove the microprocessor '2' from the system board by lifting the small handle '1' on the microprocessor. Carefully lift the microprocessor out of the socket.
    • If you are installing a new system board assembly, continue to Step 11.
    • If you are replacing only the microprocessor, go to "Microprocessor installation ".
  2. Carefully take note of the location of all cable connections on the system board. It will be necessary to reconnect them properly when installing a new system board assembly.
  3. Take note of the cable routing. It is important to route the cables properly when installing the new system board.
  4. Disconnect the diskette drive cable from the system board by sliding the plastic cable retainer upward to release the cable.
  5. Disconnect all other cables connected to the system board.

system board diagram

  1. Microprocessor heat sink
  2. Fan connectors (2)
  3. DIMM connectors (2)
  4. SATA 1 IDE and SATA 2 ISE connectors (2)
  5. PCI riser connector
  6. Speaker connector
  7. POV connector
  1. Diskette drive connector
  2. Front panel connector
  3. Power connector (P1)
  4. PATA Primary IDE connector
  5. Power connector (P2)
  6. Heat sink clamps
  7. CD audio connector
  1. Using the two blue handles provided, lift the system board assembly out of the computer.

    Note: You will have to tilt the system board assembly and move it around the edge of the power supply assembly to remove it from the computer.

  2. Take note of the location of the memory DIMMs and remove them from the system board.
  3. Install the DIMMs on the new system board in the same location as they were on the system board being replaced.
  4. Install the new system board assembly into the computer chassis by aligning the two tabs on the rear of the system board assembly with the slots in the rear of the computer chassis. Slide the system board assembly to the rear until the front edge of the system board assembly fits behind the flange in the front and is seated flush to the bottom of the chassis.
  5. Reconnect all cables that were disconnected from the system board. Make sure all cables are routed correctly.

reconnect cables

  1. Install the microprocessor on the new system board. See "Microprocessor installation". Return here after replacing the microprocessor.
  2. Install the PCI riser card.
  3. Lower the drive bay assembly into the normal position.
  4. Close the cover.
  5. Reconnect the external cables and power cords to the computer.
Purchase parts online

If you are unable to find what you are looking for, please do try the following options:
1. Lenovo Assisted Search
2. Product usage and general troubleshooting tips
3. Lenovo Support Forum
4. Technical Support Call Centre

Country Availability
Document ID : PD011671
Legacy Document ID : MIGR-53118
Last Updated :
Copyright © Lenovo 2013, all rights reserved
Was this page helpful to you?YesNo

Select Task
Drivers & Software  
Guides & Manuals  
Diagnose & Fix  
Warranty & Services  

Support Help Index
Warranty Lookup
Product Detail
Technical Specifications - PSREF
Driver Matrix
KnowledgeBase Featured Articles
Community KnowledgeBase
Community Forums
Lenovo EMC
Windows 8 Support