Miniserver and Gen1 repair

[Jonas]

Hello everyone,

Recently, my friend gave me two Loxone Miniservers for inspection: one Gen1 model and one of the newer generation. Both units appear to have suffered lightning damage, most likely through the Ethernet port.

🟢 Gen1 Miniserver (AT91SAM9G20-based)
After applying 24V power, I noticed the CPU (Atmel AT91SAM9G20) was heating up rapidly, which is a typical sign of an internal short circuit. Upon further diagnosis, I confirmed that both the CPU and the SPI Flash chip (AT25SF041), which stores the firmware, were shorted.

I proceeded to:
Replace the CPU and the Flash chip.
Flash the firmware onto the new chip.

As a result, the Gen1 Miniserver now boots successfully, is accessible via Loxone Config, and the onboard relays function correctly. I haven’t completed full testing yet, but so far it looks promising.

🔴 Newer Generation Miniserver (RK3328-based)
The newer Miniserver, however, suffered far more severe damage. One of the Ethernet traces was physically lifted from the PCB, clearly showing the extent of the surge.

Initial diagnosis revealed similar issues:
RK3328 CPU and AT25SF041 Flash chip were both damaged.
I also replaced the RK805-1 PMIC (responsible for generating multiple voltages for the CPU and peripherals) and the MP2491C, a 24V-to-5V buck converter.

Unfortunately, even after these replacements, the Miniserver still doesn't power up.

Additional Observations:

• The LINK and TREE interface chips (8-pin transceivers) are shorted.
• The EEPROM connected to the RK805-1 PMIC is damaged. This chip likely contains configuration data or power sequencing instructions required by the PMIC to correctly initialize the system.
• The STM32G471 microcontroller responsible for DI and DO is shorted as well. It appears to be running custom firmware, possibly protected from being read or cloned. The chip is not in a standard off-the-shelf configuration, making sourcing and programming a replacement difficult without official support.

My Questions:
I’m reaching out to the community for any advice or experience with similar repairs:

• Has anyone managed to fully repair a newer-generation Miniserver after such extensive damage?
• Is there any way to obtain a firmware dump or a replacement STM32G471 pre-programmed for DO/DI control?
• Is it possible to extract firmware from a working Miniserver, or are these microcontrollers protected?
• Given the state of this board, would you consider it beyond repair, especially due to firmware and part availability limitations?

Thanks in advance to anyone who can share knowledge or advice. I understand these devices are complex and proprietary, but I’m trying to learn more and possibly revive the unit if it’s within reach.

Best regards,
Jonas

Red - bad/replaced chips

Red - bad chips, Green - replaced chips

[Medes.net]

I have repaired a few loxone components but tbh this level of damage is not worth the effort. 

Unless it is purely for the education or fun of it  I might just recover the Terminals & Relays.

Never going to be able to use or sell a part that has suffered such serious physical damage. 

All the DP’s traces and board constants will have been affected by the super heating at fault point, essentially making the board an unacceptable risk going forward. 

Bit like a Cat B write off in a car. 

On 8 Jul 2025, at 17:52, Jonas <jo...@svidras.com> wrote:

Hello everyone,

<gen1-front-back.jpg>

Red - bad chips, Green - replaced chips

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[Vahur Kivaste]

Hi

I have two Gen2 miniservers both suffered from lightning through ethernet port. I took them to a very capable electronics repair shop together with a working example and they also struggeled with the same issues you are. So from my experience it is unlikely that there is a way to repair these Gen2 units. 

All the best.

[Deac99]

I've never successfully figured out a way to repair a miniserver after a lightning strike - I have replaced several over the years I'm near a mountain top and have several lightning hits per year.  But The damage for me was always via the DSL and RJ45 connections.  I finally isolated my entire network between the incoming modem  and my router with a pair of copper to fiber converters and the appropriate piece of fiber cable and so far after 6 years I've never had a problem.  Now when we get hit by lightning the only thing that gets cooked is my modem, and I get a new one from A1 free of charge.https://de.aliexpress.com/item/1005002998819713.html?spm=a2g0o.productlist.main.9.34bbzWNlzWNlUC&algo_pvid=b77740b2-8793-421b-b8f6-f0258b51d9e5&algo_exp_id=b77740b2-8793-421b-b8f6-f0258b51d9e5-8&pdp_ext_f=%7B%22order%22%3A%22259%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21EUR%218.95%216.17%21%21%2110.21%217.04%21%4021038e6617522655394562123e90af%2112000023143130996%21sea%21AT%21872445101%21X&curPageLogUid=UHl8APCMnciA&utparam-url=scene%3Asearch%7Cquery_from%3A

[Jonas]

Hey! 

I was wondering if you might have a defective Miniserver Gen2 you'd be willing to sell for a symbolic price (plus shipping to Lithuania)?

It would really help me narrow down the problems with my non-working one. Let me know if that’s something you’d consider 🙂  

Regards,

Jonas

[Jonas]

If anyone has the SPI chip firmware for the Loxone Miniserver Gen2 and is willing to share it, I would greatly appreciate it.
I already have the firmware for a unit with NANYA RAM chips, but I'm specifically looking for the firmware for a unit with IM4G16D3F RAM.
I guarantee that I will not use the Miniserver's serial number for any purpose, or you can clear it before sharing if preferred.