Installing SIMMs

As with any device, correct orientation of memory modules with their sockets is critical both for your real-world work and for the A+ Certification Exam.

SIMM modules have one end with a cut-off lower corner, corresponding to a projection, or bump , at the matching end of the SIMM socket; refer to Figure 7.2, where the cut-off side of the SIMM modules shown is the left side. This provides a keying mechanism designed to keep you from installing the SIMM backward.

To install the SIMM

1. Line up the cut-out end of the SIMM with the correct end of the socket.

2. Insert the SIMM at a 35-degree angle, ensuring that the connector is solidly in the socket, as shown in Figure 7.6. Do not touch the tin- or gold-plated connectors on the bottom of the module; this can cause corrosion or ESD.

   Figure 7.6. With either a 30-pin or 72-pin SIMM (shown here), insert the SIMM at an angle into the SIMM socket.

   

3. Push and lift the top of the SIMM until the SIMM is aligned at 90 degrees with the socket and is locked in place. If the SIMM slips out of the socket, double-check the orientation. The bump on the keyed end of the SIMM will force an incorrectly aligned SIMM out of the socket.

Some SIMM sockets are at a 90-degree angle to the motherboard, but many 30-pin SIMM sockets on motherboards or on expansion cards are at a 30-degree angle to the motherboard or expansion card. Determine the approximate insertion angle from the socket, not the board.

tip

If you need to install two or more SIMMs, make sure you install the SIMMs that will be blocked by other SIMMs first so you don't need to remove any modules to complete the installation.