Manufacturing defect?

[world101]

I received my m5stack yesterday from Amazon (sold through MakerFocus). When I opened the case to view the internal circuitry, I noticed this extra resistor connecting the circuit board with the ESP32 shield casing. I assume this is a manufacturing defect?

I had many issues trying to get the m5stack connected to the Arduino IDE, but now I think I'm past those issues. I still think I'm going to return this board to Amazon as defective. I'm not sure what solder pad is under that resistor on the PCB that may be grounding something by mistake.

[JJ]

@world101
Hi, your photo shows an earlier model M5Stack - so this is not the most recent model with 4Mb PS-RAM and MPU-9250.

This is not a manufacturing defect. (although if that cap is not connected properly on the left side you could call that bit of soldering a minor defect).

This is an intentional adjustment to the circuit.... where a SMT cap has been added between ground and RST as shown in photos below. It is equivalent to an easier, but non-permanant fix where you insert a capacitor into the ports on the right side of the unit (into GND and RST).

I have various M5Stack models including this model WITHOUT the modification that yours has. When i reflash it I just connect the cap to the ports and it reflashes fine. If that fix on yours is working you shouldn't need to do that.

If you have any problems reflashing you could check the left side connection of that cap in case the connection is not 100%... using a multimeter to test continuity. Or just resolder the left side with a quick hit from a soldering iron.

I don't know what specific issues you had trying to get it connected to the Arduino IDE - they may or may not be related to this.... depending what they were.

[world101]

Thanks JimiT. Good to know that the SMT cap helps with flashing the m5stack. I haven't had any issues flashing, so it looks like I'll be keeping this one. I ordered another one from Amazon that does not have the 2.2uF cap, so I'll return that one instead.

Question though regarding the earlier version. This is the one I ordered:
https://www.amazon.com/gp/product/B076Q92DWD/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

It specifically says it has the "Built-in MPU9250". Mine is in the grey case, not the black case. How can you tell mine does not have the MPU9250?

Regarding my issues with the Arduino IDE. As I posted on another thread here, it was something with my computer and a previous installation of the IDE. After reinstalling it from fresh, I have not had an issue since then :-)

[JJ]

@world101
Hi World101, Just to clarify, I was saying the one you have is "not the most recent model with 4Mb PS-RAM and MPU-9250" - emphasis on the AND. So your model does have the MPU9250 - but it does not have the 4 Mb PS-RAM.

At this time - Feb 2018 - all models in grey cases include the MPU9250. The models in black and white cases do not include MPU9250.

The model in the grey case that includes the 4 Mb PS-RAM features a different chip (SoC) that is much smaller and does not have a sticker on the back showing the GPIO ports. Check the photo comparison. The photo on the left does show a black case model but the chip is the same as in yours - as you can see.

Thanks for clarifying the issue you had and multiple kudos to you for following up your earlier posts and noting how you fixed things. Good operator!