Siemens SIMATIC HMI TP700 Comfort 6AV2124-0GC01-0AX0 - OS Recovery, ProSave Procedure, and TIA Portal V15.1 Compatibility

A TP700 Comfort panel that powers up, accepts Ethernet traffic, exposes a valid ProSave descriptor, and yet shows a completely dark display is one of the most common first-commissioning failures on used and surplus SIMATIC HMI hardware. The signature points to a missing or corrupt runtime image rather than a hardware fault, and it is recoverable in the field without opening the enclosure. This reference documents the full recovery workflow for MLFB 6AV2124-0GC01-0AX0 with image version V15.01.00.00_26.01, the compatibility assessment against TIA Portal V15.1 with WinCC Advanced V15.1, and the diagnostic steps that distinguish a recoverable OS image from a damaged backlight or main board.

1. Problem Description and Reported Symptom

The reported failure on a TP700 Comfort (MLFB 6AV2124-0GC01-0AX0) presents a consistent and recognisable signature:

• 24 V DC supply is applied; the panel's main board initializes (LED activity, Ethernet link LED, internal fan if fitted).
• The display remains completely dark. No Siemens splash screen, no operating system shell, no loader menu.
• The X1 Ethernet port is reachable. The IP address can be changed through the partially loaded control panel area, or assigned by the engineering tool.
• ProSave V15.1 connects without error, reads the device descriptor, and reports a valid image slot.
• Image status returns the string "The selected image can be installed."

This pattern - dark display, live ProSave connection, installable image reported - is the canonical fingerprint of an empty or corrupt runtime image, not a hardware fault. The panel has booted into the recovery loader; the loader enumerates the internal storage and exposes it to ProSave, but the active image partition is empty, unreadable, or pointing at a slot the boot loader will not chain to.

2. Device Identification - Capture Before Recovery

Always read and record the device descriptor before any recovery action. The descriptor is the single source of truth for ordering, support, and image compatibility. For the affected unit, ProSave reports:

The Siemens support entry for this order number, including datasheets, manuals, image downloads, and operating instructions, is available at the SIMATIC HMI TP700 Comfort product support page. The Comfort Panel family is the mid-to-high end of the SIMATIC HMI range, and the TP700 is the smallest of the widescreen Comfort devices.

3. TIA Portal V15.1 and WinCC Advanced V15.1 Compatibility

The TP700 Comfort is a Comfort-line panel and is programmed exclusively with the WinCC component of the TIA Portal. STEP 7 (Basic or Professional) does not configure Comfort Panels. The seller reference to "Step 7 V13" is a common first-time-Siemens confusion:

• STEP 7 Basic V15.1 covers S7-1200 PLCs only. It does not include HMI configuration of any kind.
• STEP 7 Professional V15.1 covers S7-300/400/1500 controllers and includes WinCC Basic for the Basic Panel line. It does not include WinCC Comfort, Advanced, or Professional.
• WinCC Basic V15.1 configures Basic Panels (KTP, KP, TP Basic) only.
• WinCC Comfort V15.1 configures all Comfort Panels, including the TP700.
• WinCC Advanced V15.1 configures Comfort Panels and Advanced Panels (e.g. TP1500, TP2200, MP).
• WinCC Professional V15.1 adds PC Runtime and Plant Intelligence options on top of Advanced.

Compatibility conclusion: WinCC Advanced V15.1 fully supports the TP700 Comfort 6AV2124-0GC01-0AX0. The V13 reference from the seller is a reference to a generation of TIA Portal (V13 = 2014 release, V13 SP1 = 2015 update). V13 SP1 and later all support the TP700 Comfort. TIA Portal supports project migration across versions: a V13 project opens in V15.1 with Project > Migrate, and a V15.1 project opens in any later version. The ProSave and image versions must be matched to the engineering tool, not the panel: image V15.01.00.00_26.01 is the TIA V15.1 image, exactly the generation the user has installed.

4. Root Cause Analysis

Two root causes produce the observed signature, and both are fixed by the same procedure:

1. Empty image partition (most common). The panel was shipped from a refurbisher with a placeholder image slot, or the previous project was wiped via the loader menu. The boot loader finds no bootable image and halts in the loader. The Ethernet stack and ProSave service still initialise, which is why the engineering tool can connect and report "The selected image can be installed." A panel that has never had an OS installed always returns this status.
2. Corrupt image partition. An OS update was interrupted (power loss, Ethernet disconnect, ProSave crash), or the image was written with the wrong TIA generation. The boot loader cannot chain to the broken image and falls back to the recovery loader. ProSave still sees the slot and reports it as installable rather than active.

Both cases are resolved by loading a known-good image via ProSave with the "Reset to factory settings" option enabled. The factory reset clears the image partition and any residual configuration, ensuring a clean install of the new image.

Two hardware cases produce a similar display symptom but a different ProSave signature. These are the false positives that must be ruled out before starting the OS update:

• Backlight or display failure. The panel boots, the OS loads, but the backlight is dead or the TFT is damaged. ProSave will report a normal image version, not installable.
• Power supply out of range. The main board powers up partially, the loader is reachable on Ethernet, but the display driver cannot initialise. A bench supply with current readout and voltage under-load is the fastest diagnostic.

5. Power Supply and Display Hardware Verification

5.1 Power Supply Checks

The TP700 Comfort requires a regulated 24 V DC supply. Before any software recovery, validate the supply at the panel terminals under load:

• Measure the voltage at the X80 power connector while the panel is powered. The voltage must be inside the 24 V DC window: typical Siemens specification is 19.2 V ... 28.8 V DC (24 V nominal ±20 % per typical SIMATIC HMI hardware manual). Out-of-range supply at the terminals is a common field cause of partial boot.
• Confirm the supply can deliver the panel's rated current with at least 25 % headroom for inrush and backlight peaks. Comfort Panels draw peak current during display warm-up, backlight ramp, and flash access. If the supply dips below 19.2 V during the boot sequence, the panel may stay in the loader without a visible image.
• Check for AC ripple on the 24 V rail. Industrial supplies near VFDs and large contactors can inject 100 Hz ripple that the panel's input filter cannot fully reject.
• Verify the connector is fully seated and the screw terminals are torqued. A loose connector on a vibration-loaded cabinet is a classic intermittent cause.

5.2 Display Health Checks

To distinguish a corrupt OS image from a damaged display without opening the panel:

• Shine a white-light flashlight at the display surface at a shallow angle during the boot attempt. A working backlight with a black-on-black boot screen still leaks light at the edges and through any lit pixels. A dead backlight shows no leakage. If a faint image is visible under the flashlight, the OS is running but the backlight or inverter is failing - that is a hardware issue, not an OS issue.
• Listen and feel the panel. The Comfort Panel range includes an internal fan; if the fan is running and the front LED lights, the main board is alive. If the panel is completely inert (no LED, no fan, no link light) despite a correct supply, escalate to RMA.
• Watch the X1 Ethernet port LED activity immediately on power-up. A loader-resident panel shows brief link activity even without traffic. A completely dead panel shows nothing on the port.
• Use ProSave Device status to read the boot counter and runtime hours. A panel with thousands of runtime hours is more likely to have a worn backlight than a brand-new unit.

6. Recovery Procedure - OS Update via ProSave with Factory Reset

ProSave is the Siemens service tool used to back up, restore, and update the operating system on SIMATIC HMI panels. It is installed with the TIA Portal / WinCC setup and is also available as a standalone component in the SIMATIC HMI toolset.

6.1 Prerequisites

1. PC with TIA Portal V15.1 (or at minimum WinCC Advanced V15.1) installed, including ProSave V15.1.
2. Correct OS image file for the TP700 Comfort. The image must match the TIA generation: V15.1.0.0_xx.xx. Images from a different TIA generation will be rejected. The image is typically supplied as a .img file inside a .zip archive.
3. Direct Ethernet connection between the PC and the panel's X1 port, or a switch in between. Use a crossover cable only if the PC NIC does not support Auto-MDIX - all modern PC NICs do.
4. PC Ethernet adapter set to a static IP in the same subnet as the panel. Common panel defaults are 192.168.0.1 / 255.255.255.0 or DHCP. For a blank panel, ProSave's MAC-based discovery works without any IP configuration on the panel.
5. 24 V DC supply confirmed stable at the panel terminals, as per Section 5.1.
6. Windows Firewall rule allowing ProSave and the S7DOS help service, or temporarily disable the firewall for the duration of the transfer.

6.2 Procedure - Step by Step

1. Launch ProSave. The default location is Start > Siemens Automation > SIMATIC > ProSave or, on x64 systems, C:\Program Files (x86)\Siemens\Automation\SIMATIC\ProSave\ProSave.exe.
2. In the ProSave main window, set Panel type to TP700 Comfort. Set the Connection to Ethernet (IP address) if the panel already has an IP, or Ethernet (MAC address) for first-time contact with a blank panel.
3. Enter the panel's IP address (or the MAC 28-63-36-10-49-07 for first-time discovery). Click Device status. ProSave should connect and return the descriptor matching Section 2.
4. Switch to the OS Update tab.
5. Tick "Reset to factory settings". This wipes the active image partition, user administration, recipes, and any residual configuration before installing the new image. Without this option, a corrupt image can survive the new install and continue to cause boot failures.
6. Browse to the OS image file. For a TP700 Comfort on TIA V15.1 the file is typically named TP700_Comfort_V15.01.00.00_xx.xx.img or the equivalent .upd package. Image files are available from the Siemens support entry for the order number.
7. Click Update OS. ProSave copies the image to the panel, verifies the checksum, and reboots the panel to apply it.
8. Do not interrupt the 24 V supply or the Ethernet link during the transfer. A failed flash returns the panel to the recovery loader; the procedure can be retried. Power loss mid-flash is the only failure mode that can leave the panel in a state that requires a second ProSave session to recover - and the loader is designed to remain reachable in that case.
9. When ProSave reports "OS update completed successfully", reboot the panel from ProSave (or cycle 24 V power).
10. Re-run Device status from ProSave. The image version should now match the file you just installed, and the image status should be the active version, not installable.

6.3 Alternative Recovery Path - SD Card Image Transfer

If the Ethernet connection is unreliable, the Comfort Panel range supports OS update from an SD card inserted into the panel's X51 slot:

1. Copy the OS image file to a Siemens-formatted SD card (FAT32, MBR).
2. Insert the SD card into the panel's X51 slot.
3. Power-cycle the panel. The loader detects the image on the card.
4. Confirm the on-screen prompt to install the image. If the display is dark, this prompt is not visible - the SD card method requires a working display, so it is not the right path for the reported failure mode. Use ProSave over Ethernet instead.

7. Verification and Recommissioning

After the OS update, perform the following verification sequence before deploying the panel:

1. On power-up, the Siemens splash screen should appear, followed by either the loader menu or the project (if one is present). If only the loader appears, the panel is healthy but no project has been downloaded yet.
2. From ProSave, run Device status and confirm the new image version matches the file you installed. Confirm the image status is the active version.
3. Open TIA Portal V15.1. Use Online > Accessible devices to confirm the panel is discovered. The PROFINET device name should be configurable at this point.
4. Assign the panel's final IP address and PROFINET device name, then compile the project and download it via Online > Download to device. The panel will restart into the configured runtime.
5. From WinCC, run Commissioning > Project diagnostics. Verify that all configured connections to the PLC are green and that the live tags update.
6. Set the panel's date/time, language, and regional settings. A factory reset returns these to defaults.
7. Test the touch calibration. The Comfort Panel range supports single-point and multi-touch calibration from the loader.
8. Run a full ProSave Backup to capture the working state. Storing a fresh image is the fastest path to a future recovery.

8. Field-Proven Diagnostics Matrix

9. Common Pitfalls and Field Caveats

• Mismatched TIA and ProSave versions. ProSave V15.1 will not load an image built for TIA V14 or V16 without conversion. Always match the image to the active engineering tool. The TIA Portal version installed on the PC defines the image family you must use.
• Skipping "Reset to factory settings". Without the factory reset option, residual image fragments can cause the new image to inherit corrupt configuration. Always tick the option on a known-bad panel; on a healthy panel, use Backup/Restore instead of OS Update to preserve project state.
• Power interruption during flash. A power loss during the OS update can leave the panel in the recovery loader, but the loader is designed to remain reachable so the procedure can be retried. Do not cycle power repeatedly hoping the panel recovers - it is already in the recovery state and a fresh ProSave push will resolve it.
• Confusing STEP 7 and WinCC editions. First-time Siemens users often install only STEP 7 Basic or Professional and then discover it does not include HMI Comfort configuration. WinCC Advanced, WinCC Comfort, or WinCC Professional is a separately licensed component within the TIA Portal setup. Without it, the panel can be reached by ProSave but cannot be programmed from the engineering tool.
• Windows Firewall and security suites. Windows Firewall and third-party endpoint protection block ProSave's discovery and transfer protocols. Allow-list ProSave.exe and the S7DOS help service, or temporarily disable the firewall for the duration of the transfer.
• MAC vs IP targeting. On a panel with a blank IP, ProSave must use MAC addressing for first-time contact. Once the IP is set, IP addressing is faster and supports both transfer and runtime download from TIA Portal.
• Using SD cards from non-Siemens cameras. Industrial SD cards formatted by cameras and other devices use GUID partition tables that the panel's loader does not recognise. Reformat the card with FAT32 / MBR on a PC before copying the image.
• Ignoring the ProSave log. ProSave writes a verbose log to %TEMP%. If the update fails silently in the GUI, the log shows the actual transfer error.

10. Reuse, Migration, and Project Lifecycle

The TP700 Comfort supports a complete image backup via ProSave (Backup tab). Always capture a working image as soon as the panel is commissioned. The backup includes the runtime image, the configured project, recipe databases, user administration, audit trails, and parameter sets. Restoring that backup brings the panel back to a known state in minutes. The Backup/Restore pair is distinct from the OS Update path: OS Update touches only the firmware partition, while Backup/Restore touches the project and data partitions.

When migrating a TIA V13 project to V15.1, use Project > Migrate in TIA Portal. Comfort-panel projects are forward-compatible across V13 SP1, V14, V14 SP1, V15, V15.1, and later generations. After migration, recompile the project and download it to the panel. The runtime image is independent of the project binary: a TIA V13 project running on a V15.1 image is normal, as long as the image generation matches the engineering tool, not the project generation.

When migrating from a Comfort Panel to a larger Comfort device (TP900, TP1200, TP1500, TP1900, TP2200), the project migrates with a screen-fit rescale. The TIA Portal handles the screen layout adjustment; only custom-tag pointers and screen-specific animations need manual review.

11. FAQ