# LDO Leviathan v1.3 won't flash

**URL:** <https://klipper.discourse.group/t/ldo-leviathan-v1-3-wont-flash/25659>\
**Category:** General Discussion\
**Created:** [February 19, 2026, 6:00pm UTC](https://klipper.discourse.group/t/ldo-leviathan-v1-3-wont-flash/25659 "2026-02-19T18:00:54Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![thefjordkeeper](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@thefjordkeeper](https://klipper.discourse.group/u/thefjordkeeper)\
**Post date:** [February 19, 2026, 6:00pm UTC](https://klipper.discourse.group/t/ldo-leviathan-v1-3-wont-flash/25659/1 "2026-02-19T18:00:54Z")

</div>

### Basic Information:

Printer Model: Voron v2.4  
 MCU / Printerboard: LDO Leviathan 1.3  
 Host / SBC Pi4 8GB  
 klippy.log

_Fill out above information and_ _ **in all cases attach your** _ **`klippy.log` _file_** (use zip to compress it, if too big). _Pasting your_ `printer.cfg` _is **not** needed_  
_ **Be sure to check our “Knowledge Base” Category first. Most relevant items, e.g. error messages, are covered there** _

### Describe your issue:

I cannot get this MCU to flash klipper from katapult. I’ve double and triple checked the Katapult and Klipper menu config settings. I’ve used three different USB-C cables. Powered the Pi via external PSU. Any ideas what I’m missing?!

Here’s my BASH, if that helps!

`kevin@voron:~/klipper$ python3 ~/katapult/scripts/flashtool.py -f ~/klipper/out/klipper.bin -d /dev/serial/by-id/usb-katapult\_stm32h743xx\_220045000751333232323930-if00

Connecting to Serial Device /dev/serial/by-id/usb-katapult\_stm32h743xx\_220045000751333232323930-if00, baud 250000

Detected USB device running Katapult

Detected Klipper binary version v2026.02.00-0-gc70d21ab-dirty-20260219\_110219-voron, MCU: stm32h743xx

Attempting to connect to bootloader

Katapult Connected

Software Version: v0.0.1-110-gb0bf421

Protocol Version: 1.1.0

Block Size: 64 bytes

Application Start: 0x8020000

MCU type: stm32h743xx

Flashing ‘/home/kevin/klipper/out/klipper.bin’…

[ERROR:root:Flash Tool Error

Traceback (most recent call last):

File “/home/kevin/katapult/scripts/flashtool.py”, line 429, in send\_file

```
resp = await self.send_command(

```

File “/home/kevin/katapult/scripts/flashtool.py”, line 407, in send\_command

```
raise FlashError("Error sending command \[%s\] to Device" % (cmdname))

```

FlashError: Error sending command [SEND\_BLOCK] to Device

The above exception was the direct cause of the following exception:

Traceback (most recent call last):

File “/home/kevin/katapult/scripts/flashtool.py”, line 1104, in main

```
await sock.run()

```

File “/home/kevin/katapult/scripts/flashtool.py”, line 1078, in run

```
await flasher.send_file()

```

File “/home/kevin/katapult/scripts/flashtool.py”, line 433, in send\_file

```
raise FlashError(

```

FlashError: Flash write

failed, flash address 0x8020000`

…

---

<div class="post-metadata">

**Author:** ![cardoc](https://avatars.discourse-cdn.com/v4/letter/c/ec9cab/32.png) [@cardoc](https://klipper.discourse.group/u/cardoc)\
**Post date:** [February 19, 2026, 9:55pm UTC](https://klipper.discourse.group/t/ldo-leviathan-v1-3-wont-flash/25659/2 "2026-02-19T21:55:46Z")

</div>

> [@thefjordkeeper](#):
>
> LDO Leviathan 1.3

Let us see your build settings. Run

```auto
cat ~/klipper/.config

```

And copy the output to the thread.

---

<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\
**Post date:** [April 20, 2026, 9:55pm UTC](https://klipper.discourse.group/t/ldo-leviathan-v1-3-wont-flash/25659/3 "2026-04-20T21:55:50Z")

</div>

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