Two cores broken?!

HRG

just got my M5Stack Fire delivered this week as well (from a store in Switzerland) and facing similar problems:
When switching on, the screen stays black most of the time. (Now it already seems to stay black all the time)
When switching off, strange noise when the power button is pressed.
When booting, I see normal boot messages on UART over USB.
Charging the device also works.

I have erased/updated the firmware with M5Burner several times, but does not help.
I can even program it with UIFlow, e.g. RGB bar or speaker work nicely, but the display stays off.

Unmounting the M5Go Base (bottom with the battery) and powering the device over USB alone does not help!
Shorting the battery does not help neither.
The battery power is 4V, what is fine for a LiPo, so the battery seems OK.
When powered over USB only, there is no more noise during power button presses, but I cannot switch off, only restart the device then (may-be intended?).

It is really a pity, M5Stack builds such nice devices, environment, with lots of documentation (although still not perfect) and community. And then quality issues make it unusable!

gabriele

@m5stack the voltage of the battery is 4.1V, so it works properly. The situation is the same for @liemph the core only works without the base containing the battery, so i don't have the battery, the additional ports, the led bars and the microphone, so, why i bought the fire model? When i'll have time i'll investigate further but i'm really discouraged...

liemph

@gabriele That is the most regretful part of buying Fire. Now I am using the Fire with other bases such as Base-X for playing with my Lego motors. In this case, you definitely have to unplug the battery base.

gabriele

@liemph this is very sad... @m5stack how is it possible so many bases have this kind of problem? there is some way to fix it? Can we modify the board, soldering/desldering some component?

anyway @liemph, can you tell me where did you bought the base-x? It could be a good replacement, i've bought m5stack for my son and without the base is almost useless for him, thank you

liemph

I bought it from the official store in Aliexpress:
https://www.aliexpress.com/item/4000481165186.html?spm=2114.12010612.8148356.1.eed67573HQiQdi
The base has also a battery included, so it will work without external power supply. But if you drive motors for a long time then you need to supply with external power. It has a DC connector for this purpose.

ajb2k3

@gabriele said in Two cores broken?!:

@liemph this is very sad... @m5stack how is it possible so many bases have this kind of problem? there is some way to fix it? Can we modify the board, soldering/desldering some component?

anyway @liemph, can you tell me where did you bought the base-x? It could be a good replacement, i've bought m5stack for my son and without the base is almost useless for him, thank you

This link will allow you to buy direct from the official store on this website https://m5stack.com/collections/all/products/basex?ref=pfpqkvphmgr

gabriele

@liemph and @ajb2k3 thank you for your feedback.

@m5stack do you have any answer about the problem? I think it'd be nice to give us a feedback, don't you think? There is a problem in the base board schematic? How can we fix it?

m5stack

@gabriele sorry reply late. you could contact the store, if is the product quility problem, you could got the replace.

also you could find the bottom schematic in this page

https://docs.m5stack.com/#/en/base/m5go_bottom

m5stack

@hrg sorry reply late. you could upload the UIFlow successfully but the screen still not work right?
could you check the print log by serial tool?

gabriele

@m5stack i finally had time to check the schematic. I've found a really, really strange thing: the pin 8 of the IP5306 (U3) is not connected with the +5V netlist! So i checked with the tester and it's true, there is not connection between the pin and the netlist. What is the usage of the IP5306 if it's output is not connected to anything?
So i tried to connect with the +5V netlist (i soldered a small cable to connect pin8 and the +5V pin of the m5stack bus) and now it works like charme!
At the moment i have only tested without battery (i desoldered it some days ago and i have to resolder it), but please, can you explain me this situation? Now everything works fine, led bars, microphone, anything, so there is a real issue with the schematic of the base or am i missing something? Please, explain

m5stack

@gabriele in the default situation , M5GO Core IP5306 5V output is connected to the 5V BUS. the M5GO bottom Integrated IP5306 just for the battery charge。

felmue

Hello @m5stack

I believe @gabriele talks about the IP5306 (U3) in the M5GO base (and not the IP5306 (U10) in the core).

And indeed in the M5GO base IP5306 (U3) pin 8 is not connected to 5V BUS, but looking at the schematics I think that might be intentional since pin 8 is not labelled.

It is my understanding that the IP5306 (U3) in the M5GO base is solely meant to charge the battery which then powers the core, but I could be wrong about that.

Maybe it was done like this to avoid issues in case power comes in via M5GO base and USB connected to the core?

Thanks
Felix

m5stack

@felmue yep. the M5GO bottom Integrated IP5306 just for the battery charge。 your understanding is correct

felmue

Hi @m5stack

thank you for confirming - I appreciate it.

Cheers
Felix