IBM 7133 Series Service Manual

Back Backplane Assembly| Note for Models 010 and 500: The back backplane assembly can be removed whilethe disk drive modules at the front of the 7133 remain operational. Unless you have aparticular reason to do so, do not turn off the using system or the 7133 when removing orinstalling the back backplane assembly.| 1 Use the Link Verification service aid (see the chapter about SSA service aids in the| SSA Adapters: User’s Guide and Maintenance Information manual) to ensure that allSSA loops that pass through the front backplane assembly are not broken. (Forexample, all external SSA cables are connected correctly; all disk drive modulesand, if required, dummy disk drive modules are installed correctly.)If a loop is broken, repair it, then check whether you have solved the originalproblem. If the problem remains, go to step 2.| 2 If not already done, remove (Models 010 and 020) or open (Models 500 and 600)| the front cover (see “Covers” on page 3-2).| 3 On Models 010 and 500, ensure that the disk drive modules in the back of the 7133| are no longer available to the using system.| On Models 020 and 600, stop all operations on the 7133, then remove all power| from the 7133 (see “All Power” on page 3-7).4 Remove the two back-power cards from the front of the 7133 (see “Back-PowerCards” on page 3-41).| 5 On Models 500 and 600, open the back cover (see “Back Cover (Models 500 and| 600 Only)” on page 3-6).| 6 Carefully make a note of the locations of the disk drive modules and (if present)| dummy disk drive modules that are at the back of the 7133. This action ensures| that you reinstall the modules into their original slots. (They might not all be| connected to the same SSA loop.) Attach identifying labels to the modules if you| want to.7 Remove all the disk drive modules and dummy disk drive modules from the back ofthe 7133 (see “Removing a Module” on page 3-17).| 8 At the back of the 7133, do the following actions:| For Models 010 and 500:| a. Disconnect the external SSA cables (if present) from the two back-signal| cards. To prevent damage to the SSA connector screws, ensure that you| use the special screwdriver (SSA tool, part 32H7059) to unscrew them. The| screwdriver is supplied with the 7133.| b. Remove the two back-signal cards (see “Signal Cards and Bypass Cards”| on page 3-43).| For Models 020 and 600:| a. Disconnect the external SSA cables (if present) from all four bypass cards.| To prevent damage to the SSA connector screws, ensure that you use the| special screwdriver (SSA tool, part 32H7059) to unscrew them. The| screwdriver is supplied with the 7133.3-52 7133 Service Guide