A SIMATIC Field PG identified as 6ES7717-1AA10-0AC2 (VPK1954242) became completely unresponsive after being left in standby. Disconnecting the CMOS battery and updating the BIOS restored operation initially; when the fault returned several months later, disconnecting the CMOS battery restored it again. The available evidence supports a standby-power investigation, but it does not establish a defective component or a confirmed root cause.
Separate Standby Drain From an OFF-State Fault
The reported operating state is ambiguous in the initial description: it says the PG was turned off while charging, but the later clarification identifies standby. This distinction matters because standby continues consuming energy. Record the exact power state, whether external power is connected, and whether the unit becomes unresponsive or merely has a discharged main battery.
| Observed fact | Engineering implication |
|---|---|
| Main battery falls from 100% in approximately 8 hours | Evaluate standby power consumption; do not treat this measurement as OFF-state battery life. |
| BIOS update plus CMOS-battery disconnection restored operation | Firmware or stored configuration is a candidate, not a confirmed cause. |
| CMOS-battery disconnection restored operation after recurrence | The recovery is repeatable in the reported case, but the evidence does not identify the failed subsystem. |
Check Standby Power Configuration
A BIOS option that keeps USB power enabled while the PG is off or suspended was proposed as a possible load. Windows power options were also identified as relevant. These are diagnostic hypotheses rather than confirmed SIMATIC Field PG M5 behaviors.
- Open the BIOS setup and inspect any setting that supplies USB power while the PG is off or suspended. If enabled, disable it for a controlled test.
- Review the active Windows power options and confirm which standby or sleep mode is selected.
- Charge the main battery to 100%, enter the same standby state, and record elapsed time and remaining charge.
- Repeat the test after changing only one power setting so the result can be attributed to that change.
Interpret the CMOS and BIOS Recovery Correctly
Do not treat CMOS-battery disconnection as proof that the CMOS battery caused the failure. The action can alter stored firmware configuration, while the BIOS update changes firmware; because both were performed before the first recovery, their individual effects were not isolated. The later recovery after CMOS disconnection makes stored configuration a reasonable investigation path, but it still does not prove causation.
Escalate a Recurring Failure
If the PG again becomes completely unresponsive, document the selected power state, charger connection, battery percentage before standby, elapsed time, BIOS power settings, Windows power options, and which recovery action restores operation. Submit those observations with the identifiers 6ES7717-1AA10-0AC2 and VPK1954242 through an official Siemens support channel. A recurring total-dead condition on a recently supplied unit requires manufacturer diagnosis rather than repeated CMOS disconnection as the permanent remedy.
FAQ
Why does my SIMATIC Field PG M5 die after 8 hours in standby?
The evidence confirms a drop from 100% charge over approximately 8 hours in standby but does not confirm the cause. Check BIOS USB-power behavior and Windows power options, then repeat a controlled standby test.
Does unplugging the CMOS battery prove the CMOS battery is defective?
No. CMOS disconnection restored operation in the reported case, but it may also reset stored firmware configuration; the evidence contains no component test proving that the battery itself failed.
What should I send Siemens support for a recurring Field PG failure?
Provide identifiers 6ES7717-1AA10-0AC2 and VPK1954242, the exact power state, charger status, battery percentage, elapsed standby time, BIOS and Windows power settings, and the recovery action that restored operation.