# Mcu not connecting & network dropping **URL:** \ **Category:** General Discussion\ **Created:** [July 29, 2024, 11:42pm UTC](https://klipper.discourse.group/t/mcu-not-connecting-network-dropping/17969 "2024-07-29T23:42:39Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![dabidov](https://avatars.discourse-cdn.com/v4/letter/d/6bbea6/32.png) [@dabidov](https://klipper.discourse.group/u/dabidov)\ **Post date:** [July 29, 2024, 11:42pm UTC](https://klipper.discourse.group/t/mcu-not-connecting-network-dropping/17969/1 "2024-07-29T23:42:39Z")
### Basic Information: Printer Model: Elegoo Neptune 3 Pro MCU / Printerboard: stock mainboard Host / SBC: Raspberry Pi 4 over USB 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’ve been encountering a pretty weird issue lately. I recently moved and connected my printer to a different wifi than it had been prior. I had no issues with this, and the printer worked as normal. I then would notice that during a print, I would no longer be able to connect to the printer (mainsail could not connect to Moonraker). The print would continue with no issues, and after a day or two it would reconnect. A couple print attempts in, I had noticed that the printer began having mcu ‘mcu’: Unable to connect errors. When I noticed these, I would simply firmware restart and all was well after a few minutes. The other day I started a temp tower to run, and the connection dropped as it usually did. The print continues, and I thought nothing else of it. It took about 3 days to connect back to the printer, and ever since then I have been unable to get past the mcu ‘mcu’: Unable to connect errors. Some things I thought of to help narrow it down: There was no power outage or brown out in this timeframe Nothing has been unplugged since then The printer itself has been powered off once between the print finishing and the printer reconnecting I do not have Ethernet to test this out There were no changes to any config files In an attempt to remedy the issue, I fully updated everything in the mainsail update manager [logs-20240729-194031.zip](https://klipper.discourse.group/uploads/short-url/htMU55V9wMw4Id9CYX10bq7CQk0.zip) (8.1 KB) ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [July 30, 2024, 7:24am UTC](https://klipper.discourse.group/t/mcu-not-connecting-network-dropping/17969/2 "2024-07-30T07:24:54Z")
Sounds like an issue with the underlying Linux of your RPi4. Dropping the connection is not Klipper related. I’d try a new SD card and provision a fresh Linux on it. ---
**Author:** ![dabidov](https://avatars.discourse-cdn.com/v4/letter/d/6bbea6/32.png) [@dabidov](https://klipper.discourse.group/u/dabidov)\ **Post date:** [July 30, 2024, 1:21pm UTC](https://klipper.discourse.group/t/mcu-not-connecting-network-dropping/17969/3 "2024-07-30T13:21:40Z")
If I have sonar enabled then shouldn’t it reconnect after a short period of time? Also, is there a chance that re-flashing the SD will fix this MCU error as well? ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\ **Post date:** [August 29, 2024, 11:22pm UTC](https://klipper.discourse.group/t/mcu-not-connecting-network-dropping/17969/4 "2024-08-29T23:22:37Z")
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