Power via USB stopped working after just one hour #morserino #issues


Florian Meißner DO1MRV
 

Hi @all,

After I received my Morserino 2nd generation, Firmware 4.0.1, last week, I finally assembled it today and tested it. Therefore I powered the Morserino via its USB port on the Heltec module and it stared up fine as expected. But after about an hour, the Morserino stopped working completely that way. No more LED indications, dark screen, no sound what so ever.

But when I disconnect the USB cable and instead power the Morserino via the Lipo battery, it still works like a charm. So as already discussed in https://morserino.groups.io/g/main/topic/78721108?p=,,,20,0,0,0::Created,,usb,20,2,20,78721108,ct=1&ct=1, there seems to be a problem with the 5V distribution from the USB socket.

I also did measure the voltage across the power pins of the Heltec module in the following configurations. For all tests with USB power I used the same powerbank / cable setup, the powered the Morserino successfully at the beginning as well as several different USB power supplies and PCs.
Heltec module inserted in the Morserino
Powered via USB, battery disconnected
5V - GND       0V
Vext - GND    3,3V
3V3 - GND     3,3V
Powered via battery, USB disconnected
5V - GND       0V
Vext - GND    0V
3V3 - GND     0V
Heltec module removed from Morserino
Powered via USB, JST on the bottom disconnected
5V - GND       0V
Vext - GND    0V
3V3 - GND     0V
Unfortunately, the thread linked to above did not mention what really was at fault. I hope, you can help me with this one. Since the Morserino is brand new, it is somewhat disappointing that one function quit that rapidly!

73,
Florian DO1MRV


Willi, OE1WKL
 

Some power banks switch off after a while when there is not enough drain on their battery... you can buy circuits on eBay etc to prevent that.
This could be one reason it stops working. Did you test it with some other usb supply, e.g a computer or a phone charger?

Willi

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Florian Meißner DO1MRV
 
Edited

Hi Willi,

I tried two different phone chargers, a dedicated Raspberry Pi power supply and the USB port on two different computers. All with the same results. Also I used at least three different cabels which all do power my Rpi very fine!


Florian

 

Am 01.04.21 um 18:54 schrieb Willi, OE1WKL:

Some power banks switch off after a while when there is not enough drain on their battery... you can buy circuits on eBay etc to prevent that.
This could be one reason it stops working. Did you test it with some other usb supply, e.g a computer or a phone charger?

Willi

Von meinem Mobiltelefon gesendet





Willi, OE1WKL
 

The 5V pin is a power input pin and can be disregarded here. Both 3V3 and Vext should show 3.3 V when the Morserino has started up, no matter how it is powered.

Pls check also the soldering of the Heltec's header pins - if there is a problem with either ground or 3V pins you might see symptoms similar to yours...

Willi

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Florian Meißner DO1MRV
 

The pins look normal. Anyway, it did work via USB for about an hour!

On 01.04.21 19:10, Willi, OE1WKL wrote:
The 5V pin is a power input pin and can be disregarded here. Both 3V3 and Vext should show 3.3 V when the Morserino has started up, no matter how it is powered.

Pls check also the soldering of the Heltec's header pins - if there is a problem with either ground or 3V pins you might see symptoms similar to yours...

Willi

Von meinem Mobiltelefon gesendet



Clay Nicolsen
 

It could be a cold solder joint that intermittently goes open.

I might suggest re-flowing the solder joints.

Clay NF7X

On Thu, Apr 1, 2021 at 10:15 AM Florian Meißner DO1MRV <do1mrv@...> wrote:
The pins look normal. Anyway, it did work via USB for about an hour!

On 01.04.21 19:10, Willi, OE1WKL wrote:
> The 5V pin is a power input pin and can be disregarded here. Both 3V3 and Vext should show 3.3 V when the Morserino has started up, no matter how it is powered.
>
> Pls check also the soldering of the Heltec's  header pins - if there is a problem with either ground or 3V pins you might see symptoms similar to yours...
>
> Willi
>
> Von meinem Mobiltelefon gesendet
>
>
>
>






Willi, OE1WKL
 

Did you try to remove three Heltec and power it through usb? What is happening if you do so?

W

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Florian Meißner DO1MRV
 
Edited

Yes, I did. Please see my first post again where I listed exactly what I tried and what I did measure.

 

On 01.04.21 19:27, Willi, OE1WKL wrote:
Did you try to remove three Heltec and power it through usb? What is happening if you do so?

W

Von meinem Mobiltelefon gesendet





Willi, OE1WKL
 

Under these circumstances I have to assume that the LiPo charging / voltage regulator circuit on the Heltec has given up.
I will ship you a new Heltec Module free of charge.

73
Willi


Florian Meißner DO1MRV
 

Thanks a lot! Do you still have my address from the order or is there a way, I can mail you a shipping address?

On 01.04.21 20:06, Willi, OE1WKL wrote:
Under these circumstances I have to assume that the LiPo charging / voltage regulator circuit on the Heltec has given up.
I will ship you a new Heltec Module free of charge.

73
Willi





Willi, OE1WKL
 

I still have your shipping address...
W

Von meinem Mobiltelefon gesendet

Am 01.04.2021 um 20:09 schrieb Florian Meißner DO1MRV <do1mrv@darc.de>:

Thanks a lot! Do you still have my address from the order or is there a way, I can mail you a shipping address?

On 01.04.21 20:06, Willi, OE1WKL wrote:
Under these circumstances I have to assume that the LiPo charging / voltage regulator circuit on the Heltec has given up.
I will ship you a new Heltec Module free of charge.

73
Willi