Salvaging unreliable MCUZone MR5210P M.2 to Ethernet/USB board/box?

Thanks to everyone here on this forum reporting reliability problems with their MCUZone M.2 to Ethernet/USB boards, I’ve ordered a rework.network replacement instead.

That said, this MCUZone box wasn’t cheap. I am wondering whether it can be repaired or otherwise made to work reliably.

The suspicion is that they don’t provide consistent-enough power (either the voltage sags or the current sags or both) to run the 5G modems it is supposed to support (I ran into problems with an RM520N-GLAA). I bought a massive overkill 12V power supply that can supply 36W if needed, but that did not help.

I am wondering if anyone has tried any of these possible solutions.

a) Does it work reliably on PoE? I don’t have PoE and can’t test this.
b) what if we just use IoT modems that have lower power draw such as older 4G LTE modems? If anyone has gotten a particular modem to work reliably, please let us know the model. I am considering using a Quectel 4G LTE modem that is known to draw less/lower power.
c) Maybe we can swap out a capacitor on the board. I can do surface mount soldering. Many of the Quectel Hardware Design Guides have reference power supply designs in them. They often mention that a certain capacitor has to be at least some rating to work with the given modem.
d) other ideas that work reliably are welcome.

Thanks in advance. I’m just hoping to give extra use/life to all these expensive MCUZone boxes everyone has sitting around doing nothing. They’d still be useful if we can pop in lower-power-draw 4G LTE modems (for example, I can’t really use my 5G modem anyway because there is barely any 5G signal where we are).

I checked a few of the Quectel 4G LTE models to look at their power requirements.

If it’s voltage that’s sagging, then it’s likely none of the 4G models will work, since the one I looked at all had the same minimum voltage threshold of 3.135V before automatic shutdown as the 5G RM520N-GL.

But if it’s current that’s sagging, 4G LTE modems might work. Of the ones I checked, they had lower current requirements. One was 2.0A minimum, another was 2.7A minimum. The RM520N-GL requires 3.0A minimum continuous current.

I’m not sure yet whether it’s current or voltage or both that sag. My hope is that it’s only current that sags, which would mean a 4G LTE modem could work reliably in my MCUZone box.

If any of you happen to have an unreliable 5G MCUZone M.2 to Ethernet/USB board and also a Quectel 4G LTE modem, could you insert the 4G LTE modem and check it for reliability and let us know how it goes? Thanks in advance!

Dear @dchang0
Sorry about this, we didn’t familar with this device.

Hope other guys in forum will help you.

1 Like

I received my new rework.network M.2 to Ethernet box today and transferred the Quectel RM520N-GLAA from the MCUZone MR5210P box to it.
Right away, it was clear the internet connection was more stable.
For one, I was not able to visit these forums when the modem was in the MCUZone box, but now I can!
Basically, the unreliability expressed itself like this: initial data requests would work, but after the first second or two, later requests would hang and never complete or complete much later. For many large or simple websites, this was not a problem, but for websites with a lot of background calls to various APIs, it was fatal.

Anyway, I am going to decide whether to buy a Quectel 4G LTE modem to pop into the MCUZone box to test my hypothesis that it can support 4G modules with their lower current requirements.