MAP21B0 RPC card reporting loss of +5V for force power off circuit

Each RPC card provides a +5v source voltage to the RPC card J204 connector that the optional customer remote force power off (FPO) switch cable connects to. If the RPC card detects that the +5V is not present, the failure can be in the RPC card itself, or the customer circuit (if connected).

MAP21B0 Section-1

Procedure

  1. The RPC card is detecting that it is not providing +5v to its connector J204.Locate the RPC card listed in the serviceable event FRU list. Is a cable connected to the RPC card J204 connector?
    • Yes, disconnect the cable and go to step 2.
    • No, return to the serviceable event and replace the RPC card.
  2. Isolate if the loss of +5v is a failure within the RPC card, or if there is an external short to ground on the cable assembly provided by the customer.
    1. Disconnect the customer cable from connector J204.
    2. Return to the serviceable event and do a pseudo replace of the RPC card. A pseudo replace means you use the normal FRU replace procedure, but do not actually replace the RPC card with a new one. The FRU verify process will determine if the original failure is still occurring.
  3. Does the original failure still occur?
    • Yes, the RPC card is failing, repeat the FRU replace process, but this time replace the RPC card.
    • No, the failure is external to the RPC card. Have the customer isolate the short circuit in their switch cable assembly.