SINUMERIK 802D sl "No Boot Device Present. Halting" - CF Card Recovery Procedure

The SINUMERIK 802D sl (and 802D sl T/M plus variant) is a panel-mounting CNC control used on turning and milling machines. The control stores its system software, PLC project, drive data, compensation tables, and the option/license keys on a removable CompactFlash (CF) card seated on the rear of the operator panel front. When that CF card fails or loses its partition table, the embedded BIOS displays the diagnostic line:

No boot device present.r>halting

This article documents the root cause, the diagnostic path, and the field-proven recovery workflow for the 802D sl boot alarm, using the example of a failed CF card with Siemens part number 6FC5810-2YG14-1YA0 (SW-Version T/M PLUS, serial example 116815C1508V0201).

1. System Overview and Boot Architecture

The 802D sl boots from the CF card slot on the back of the operator panel. The card is accessed through a hinged flap or a metal cover (depending on the panel revision). The internal BIOS looks for a specific boot signature on partition 0 of the CF card; if the signature is missing, the controller outputs the black-screen "No boot device present. Halting" message and stops.

Refer to the SINUMERIK 802D / 802D base line Commissioning Manual (English, 08/2005 edition) for the original hardware description of the operator panel, the CF card slot location, and the boot sequence.

2. Fault Symptom

Observed behavior on a 802D sl that has suffered a CF card fault:

• 24 VDC supply at the operator panel is present (PCU/CCU power LED illuminated).
• Display backlight does not turn on, or turns on but remains completely black.
• No SINUMERIK splash, no Channel reset, no alarm line.
• After several seconds, the following BIOS diagnostic is printed on the screen:

  No boot device present.r>halting

• The system is unresponsive to NC Start, Reset, or any key on the keyboard.

This symptom is unambiguous: the embedded PC core cannot find a valid boot device on the CF slot, and execution halts before the SINUMERIK HMI loads.

3. Root Cause Analysis

3.1 Primary Cause: CompactFlash Card Failure

The 802D sl was designed around an industrial CompactFlash card as the primary mass-storage device. Field experience shows that consumer-grade CF cards used as a replacement fail first; the OEM-specified industrial CF card (MLFB family 6FC5810-2YG...) carries a wider operating-temperature grade and a more robust wear-leveling controller. Typical failure modes are:

1. Wear-out of the internal NAND after years of PLC project save/load cycles.
2. Loss of the Master Boot Record (MBR) or partition table due to a power dip during a write operation.
3. Mechanical damage or bent pins on the CF card or in the slot (look for dust, swarf, coolant ingress).
4. Use of a non-Siemens CF card that is not on the released compatibility list.

3.2 Secondary Causes to Rule Out

Before declaring the CF card dead, exclude the following because they can produce the same boot message:

4. Field Procedure: Confirming CF Card Failure

1. Power down the machine. Lock the main disconnect. Wait at least 60 s for the DC bus to discharge.
2. Open the cover over the CF card slot at the rear of the operator panel (typically two Phillips screws).
3. Press the CF card eject button and remove the card. Inspect the 50-pin socket for coolant, swarf, or bent pins. Use a magnifier and a flashlight; do not blow into the slot.
4. Read the label and record the MLFB, SW version, and serial number. The replacement card must match the SW-Version printed on the label (e.g. T/M PLUS) for the correct firmware and PLC firmware version.
5. Insert the CF card into a USB CF-card reader connected to an external engineering PC running Windows 10/11.
6. Open Disk Management (diskmgmt.msc). The expected view is: one FAT16 primary partition labeled with the SINUMERIK file set, plus a smaller system partition containing the bootloader. If Disk Management reports the card as RAW, unallocated, or shows an Unknown partition, the card is corrupt.
7. Run chkdsk <drive> /F from an elevated command prompt only if the partition still mounts read-only. A successful clean run with no lost clusters may indicate a soft fault; a repair that recovers data, or one that fails outright, indicates a hardware-level failure.
8. If chkdsk cannot run, attempt a sector-by-sector copy with ddrescue (Linux) or HDD Raw Copy Tool (Windows). When the copy aborts on the first unreadable block at the MBR, the diagnosis is confirmed: the CF card must be replaced.

5. Sourcing a Replacement CF Card

The SINUMERIK 802D sl is supplied in some markets with a pre-imaged industrial CF card under MLFB 6FC5810-2YG14-1YA0 (T/M plus). Equivalent cards in the same MLFB family include:

Procurement paths in priority order:

1. Siemens regional sales office (e.g. Siemens AG Digital Industries, Factory Automation). The card is identified by the MLFB; the office can also issue the matching license key.
2. Siemens Industry Online Support (SIOS) – for end customers with a valid support contract, the Web License Manager (WLM) at siemens.com can reissue the option key when the hardware serial is provided.
3. Authorized Siemens solution partner – useful if the regional office has limited stock for an obsolete SW version.

If the regional Siemens office is not reachable (e.g. limited local presence), open a service request through the Siemens support hotline for the country. Provide the serial number of the control and the SW version on the original CF card label so the replacement contains the same image and feature set.

6. Restoring the System Image

The replacement CF card is supplied either pre-imaged (preferred) or blank. If the card is pre-imaged with the T/M plus system software, no further installation is required; the new card is a direct drop-in.

If the card is blank, the system software must be loaded using the procedure in the SINUMERIK 802D Commissioning Manual:

1. Copy the SINUMERIK 802D sl T/M plus system-software image (typically a directory tree with mmc2, bd, setup.com, etc.) to a USB stick formatted FAT32.
2. Insert the USB stick into the front USB port of the operator panel before the replacement CF card is fitted.
3. Power up; the BIOS will boot from CF and detect the missing image. With a valid image on the USB stick, the system will perform a one-time self-install onto the CF card.
4. Allow 5 – 15 minutes for the install; do not power down during this window. Progress is shown on the panel display.

7. License / Option-Key Recovery

The license key for the SINUMERIK 802D sl is tied to the hardware serial number (the seven-segment serial, e.g. 116815C1508V0201) and is stored on the CF card as a separate file. Replacing the CF card means the key is lost. Recovery workflow:

1. Identify the original serial of the control (printed on the nameplate on the side of the operator panel).
2. Collect the option set you had activated (e.g. ShopMill, ShopTurn, additional axes, advanced technology functions). Cross-check with the original machine invoice or the OEM's configuration file.
3. Open the Web License Manager (WLM) at siemens.com. Log in with the customer SSO account.
4. Select the affected SINUMERIK 802D sl serial, and choose CoL (Certificate of License) reissue. The system generates a new license-key text file that can be downloaded and copied to /siemens/sinumerik/sys on the replacement CF card, or imported through the HMI menu Setup → License after boot.

If WLM is not accessible in your region, the regional Siemens office can perform the reissue on your behalf when presented with the serial and a copy of the CoL document.

8. First Boot Verification

After installing the new CF card and applying the license, power the system up. The 802D sl normally runs through the following checkpoints within 60 – 90 s:

1. BIOS prompt briefly visible (BIOS version 1.x for T/M plus).
2. Siemens splash screen, then SINUMERIK HMI start page.
3. Reference-point confirmation dialog (if axis positions are not yet referenced).
4. Alarm list appears, often with a single cleared alarm 8080 "Power On" or an NCK reset alarm.

Verify the following from the HMI:

9. Alarm-List Behavior After a Hard Reset

Once the controller has booted, the alarm list will show entries because the PLC was running an in-flight program when power was lost. The first alarm in the list is always the alarm last occurred. If more than eight alarms have occurred, the first seven alarms plus the newest alarm are shown. The list can be cleared with Cancel alarm (vertical soft key) once the underlying cause is resolved.

The reference to "more than 8 alarms" is documented in the SINUMERIK 802D Commissioning Manual (08/2005), section on alarm history. Use this to verify that the alarm list is operating correctly after the card swap.

10. Preventive Measures

To minimize the risk of a repeat boot failure:

• Use only Siemens-recommended industrial-grade CF cards. Consumer cards lack the wear leveling for the SINUMERIK write pattern and fail in 1 – 3 years of continuous use.
• Keep the panel enclosure closed. Coolant mist and airborne oil cause the card slot to corrode and intermittently disconnect.
• Back up the CF card to USB once per quarter (HMI menu Setup → Service → CF card backup). The image is restorable with the same procedure as section 6.
• Verify the 24 VDC supply is within tolerance; under-voltage during PLC save operations is a major cause of MBR corruption. Use a regulated, low-noise 24 V industrial power supply with battery backup on the control leg.
• Replace the CR2032 coin-cell on the operator panel every five years. A dead battery can corrupt the BIOS configuration and the option-key file.

11. Troubleshooting Matrix

12. Summary

A black screen on the SINUMERIK 802D sl displaying "No boot device present. Halting" is a deterministic symptom of a CompactFlash card fault. The recovery path is well-defined: confirm the card failure with a PC-based reader, source a pre-imaged replacement CF card with the matching SW version (e.g. 6FC5810-2YG14-1YA0 for T/M plus), swap the card, and reissue the license key from the Web License Manager using the original control serial. A clean image restores normal boot within 60 – 90 s, and the alarm list will clear once PLC and drive references are confirmed.

Where the Siemens regional office is not active, use the Web License Manager and the global Siemens support hotline to obtain the software and the license. Do not attempt to reformat a partially-readable card; the next step is always a known-good image from Siemens.