28Installing fan trays for the S12504X-AF switch1. Orient the fan tray correctly.To install a fan tray in the FAN1 slot, orient the fan tray so that the LEDs are on the left side ofthe front panel. To install a fan tray in the FAN2 slot, orient the fan tray so that the LEDs are onthe right side of the front panel.2. As shown by callout 1 in Figure 26Figure 26, align the positioning pin on the fan tray with thepositioning hole in the chassis.3. As shown by callout 2 in Figure 26, hold the fan tray handle and insert the fan tray into the slot.Keep the fan tray as straight and stable as possible while inserting it into the slot.4. As shown by callout 3 in Figure 26, fasten the captive screws on the fan tray.Figure 26 Installing a fan tray for the S12504X-AF switch(1) Align the positioning pin on the fan tray with the positioning hole in the chassis(2) Insert the fan tray into the chassis (3) Fasten the captive screws on the fan trayInstalling power modulesThe power module slots are located at the two sides of the rear panel.The installation procedure is the same for DC and AC power modules.To install a power module:1. If a filler panel is installed in the slot, remove the filler panel first.{ For a filler panel as shown in Figure 27, thread a flat-blade screwdriver through the hole inthe handle of the filler panel and pull the filler panel out.{ For a filler panel as shown in Figure 28, use your forefinger to hold the filler panel throughthe hole and pull out the filler panel along the guide rails.2. Correctly orient the power module.If you install the power module in a left power module slot, make sure the latch is above thehandle. If you install the power module in a right power module slot, make sure the latch isbelow the handle.3. Holding the handle of the power module with one hand and supporting the bottom of the powermodule with the other, slide the power module along the guide rails into the slot until you heara click.