M4 v2 New build may have damaged the board

[ravenhaven]

Hello, I need some advice on whether I have ruined my new M4. Prior to connecting Kissys expantion board I was able to connect to ground control only using USB power with all leds lighting up correctly. I soldered the expantion board using paste and heat gun and I thought I did a good job as it was my first time soldering these tiny components.I checked all the solder points with a magnify glass and was convinced every thing was OK.
When I first connected the M4 with the expantion board on top using the USB to the computer the the red led between legs 1 and 4 light up solid and the red led charge light one flash and stays off. The device manager sees the M4 but I cannot connect to ground control as I could before adding the expantion board.
I removed the expantion board tried to connect again and the red led stays on soild with a quich flash from the charge led.
I only used the USB to power up the board and have not used the lipo.
Have I damage the board?
Thanks for any advice
Wally

[JussiH]

I dont think your board is fried - sounds more like a boot or undercurrent problem on the USB port.

Try the following:

Try USB again - Keep the board still while booting.

Try another port - Not all USB ports are created equal and some simply wont deliver enough current. This will become especially evident when trying to power peripherals like expansion boards.

Try and hook a 5V powersource to Vusb pads.

Connect a charged 1S Lipo to the battery pads and see if the board will turn on and off with the On/Off pushbutton:

http://autoquad.org/wiki/wiki/m4-microc ... onitoring/

[ravenhaven]

Thanks for your help Jussi. I will try another USB cable and change the port and also connect the lipo to see if I cant get the board back. Anyway I have ordered another one just in case its kaput. I wont be back home till monday so will try then and let you know.Do you offer a service to solder the kissy extention board as I have also ordered another and here in Perth I dont know who would do the soldering for me.
Wally

[JussiH]

I am working on a updated production version of Steves expander, but its gonna take 4-5 weeks before the first ones can be here. I cant offer to assemble any at the moment, I have to focus the little time I have to make other more important things happen on the HW front...

[OlliW]

[ravenhaven]

Hi olliw
On receiving the board I connected to ground control with the bare M4 with no problems using USB. Later I soldered the kissy expantion board and mated it up with M4. and plugged it into the computer to try and connect to ground control. The only leds to light this time up were the red led between one and four leg of the m4 frame which indicates power and remains on solid and the other led is the one red charge led which just flickers once.I knew something was wrong as the other leds did not light up for the boot sequence.
I removed the expantion board and with just the bare M4 and USB cable for power I connected to the computer again expecting the leds to light up in sequence but only the one red power indication lights up and the charge led flickers once all the rest of the leds are blank. The computer sees the USB connection but the bare board with out the expantion board cannot now connect to ground control. The only power applied to the board is from the USB as I have not yet soldered the battery leads to the M4. The only other thing I did was to check the windows 8.1 driver for the board which is OK.
I soldered the expantion board myself and may have used a little too much solder paste as this is the first time I have soldered such small componants, I doubled checked all solder points visually before connection which seemed fine but what is unders the surface mounts componants I cant see and I dont have the electrical experiance to check using multi meter other than checking continuity and voltage.
Thank you

[OlliW]

so, it's the 2nd, removing the expansion didn't bring the M4 back
I was asking because I think I had a very similar, if not the same, incident
(for the details, it's describe here, http://www.rcgroups.com/forums/showpost ... stcount=62, and the following posts)

My M4 did also work nicely just powered by USB, but suddenly for no reason it didn't do anymore. As in your case just the red power led goes on, but the MCU doesn't boot and hence no other leads and no USB communication is possible. So, something went bad on the board (I carefully checked it's not the PC, cable etc.). Sounds very similar to what you describe, so it might be that its not related at all to the expansion board, but that it was just a coincidence that it happened exactly then.

Anyhow, I could get around it. I removed the usb esd protection chip, and then found that I just have to plug the M4 also to a lipo battery, and everything works well again. I'm not sure if it was needed to remove the esd chip. So I suggest that you just try and connect a battery to the M4, and check if things would work then. This at least works for me, and although not optimal I find this an acceptable situation.

I have not yet identified what got destroyed, I could not yet fully decipher the electric scheme. But it is obvious that something with the distribution of the USB power to the MCU doesn''t work anymore. There is a double fet on the board and it's not yet clear to me what it is used for, my current feeling is that it is the culprit.

Anyway, connect a lipo, and if it's then working, then you're back in business (and I know that I'm not the only one LOL).

good luck, Olli

[ramminger]

Hi Wally,

i sufferd with the some problem. First time i pluged the new M4 Board into my USB-Port everything worked
fine. Installation of the USB-Drivers was fine and GC could connect the M4 Board. But after some configuration trys and
errors and some Bord-Resets the Problem appears as you described.

I solderd now an Battery-Plug to the Board and connected with an Ladybird-Lipo. When i started the Board with the Power Switch it bootet perfect and everything went fine. Then i could connect with the USB and connection with GC was also o.k.

When you connect a Battery to the Board DOUBLECHECK the POLARITY. There are small Lipos whitch have reversed Connectors.

I hope you are sucsessful
Ulrich

[OlliW]

so, you're saying that initially you could power the M4 from USB alone and it would work, but that it suddenly did do that anymore, and that henceforth one has to use a battery in addition to it?

this would make it when 3 cases where this happened

would indicate that there is indeed something wrong with the M4v2's power path design

in order to diagnose what might be going on, could you do this and confirm/disconfirm this behavior:

1) then you plug the M4 to the USB only, then
1a) only the red led goes on,
1b) and it flickers a little bit

2) when you know connect the M4 to a battery in addition, the
2a) the M4 starts to work, i.e. all the other leads come up
2b) the red led got much stronger and shine bright and clear
2c) one doesn't have to press the little power switch

3) when you now disconnect the battery but keep it connected to USB, then
3a) continues to work as in (2), that is it runs and all leds are doing what they are supposed to do and the red led is bright

I think that the answers to these points should allow anyone with a knowledge of the electric scheme to identify the broken part

(the error pattern suggests that a switch which distributes the USB power to the M4 isn't triggered anymore with the USB only)

[ramminger]

@ Olli

now i did some Tests as you described. To avoit additional problems from PC-Usb, Drivers, etc. i used an stupid USB-Powerbank as Power-Source.

1. USB only connected. Red led lights dimmed with some flickering. The Voltage between DGND (J2-1) and +V OUT (J2-2) measured are only 2.13 Volts.

2. When i then connect the battery the red led becomes bright and the M4 starts without pressing the Power Button. The output Voltage jumps to 3.3 Volts.

3. Yes, it continues to work and the red led stayes bright.

I think too there is probably a problem in the power distribution.

I can live with this little problem, but someone inexperienced could have troubles with that.

Ulrich