[Arm-netbook] EOMA68-A20, MD 1.7 severe Power Problems

Pablo Rath pablo at parobalth.org
Tue Aug 11 12:34:45 BST 2020


On Tue, Aug 11, 2020 at 11:37:41AM +0100, Luke Kenneth Casson Leighton wrote:
> On Tuesday, August 11, 2020, Pablo Rath <pablo at parobalth.org> wrote:
> 
> > On Sun, Jul 26, 2020 at 10:29:07PM +0100, Luke Kenneth Casson Leighton
> > wrote:
> > > On Sunday, July 26, 2020, Pablo Rath <pablo at parobalth.org> wrote:
> > >
> > >
> > > >
> > > > I have a power supply from a Huawei Tablet (Output 5V, 2A) and one from
> > > > an old Ipad Mini (Output 5V, 1A) both with a wall plug and a female USB
> > > > socket.
> > >
> > >
> > > ok you need... a male to male cable.
> > >
> > >
> > > > Can I use one of them with a standard USB 2.0 USB A to USB A (male to
> > > > male) cable?
> > >
> > >
> > > yes that's the one.  usually used on laptop fan bases.
> > >
> >
> > Bought and tried the cable but I have no working UART.
> > So far I have tried both USB-ports on the Micro Desktop, powering with
> > the USB-port of my laptop and with the power supply (Output 5V, 2A).
> > I think that the cable is working because it is new and it can load my
> > smartphone (with an additional USB-OTG female USB to Micro USB adapter).
> > Is there anything else I can try?
> > It is frustrating. Without UART connection I don't know if anything
> > happens at all when connecting the USB cable to the Micro Desktop.
> 
> 
> does the USB UART happen to be one which has flashing LEDs on it?
> 
No. There are no LEDs on it.

> there is another way to power the Card: *carefully* plug in a USB-OTG cable.
> 
> however the SY6280 should prevent power getting back through to the Housing.
> 
> it will however not prevent the 3.3v Tx and Rx of the UART from lighting up.
> 
> if the SY6280 was damaged at the time then it will not be letting power
> through to the Card.
> 
> therefore powering via USB-OTG will bypass that.

Ok. I have tried that now. Pressed "2" while applying power over USB-OTG
but an Allwinner USB FEL device is not found with 'sunxi-fel version'.
Also tried to boot with my known working µSD-Card but there is no output
on UART.

Pablo



More information about the arm-netbook mailing list