>On Sun, Jul 26, 2020 at 10:54:27AM +0100, Luke Kenneth Casson Leighton wrote: >> On Sun, Jul 26, 2020 at 10:33 AM Pablo Rath <[email protected]> wrote: > > > > I am very sorry to inform everyone on this list that I had a severe power > > problem with my Micro Desktop 1.7. > > I applied power to the DC Jack and the area right to the jack burned > > out. (see attached picture). > > thank you for sending this to the list, as i asked, after you sent it > initially privately. i had this happen to a 1.5 MD board 3 years ago, > but no others, despite them running for prolonged periods of time. > > what i noticed about that board was that the inductor was not properly > soldered down. this would be insufficient contact, introduce > resistance, and at that point the RT8288 would go unstable.
Ok. As you have probably deduced from my questions I am not really into hardware. Thank you for all your explanations and clarifications. I still try to wrap my head around what should work straight away, what could work with the right modifications and what can never work... [...] > > As I said I am very sorry that I screwed up. > > Luke, do you have any ideas what went wrong? > > not in the slightest. or - maybe: have a look at the contact points > where the inductor sits on the PCB. there should be quite a lot of > solder, there. Sorry for the dumb question but where can I find the inductor? > > Do you think this > > +also destroyed the computer card? > > when it happened for me it did no damage. all i did was (because i > didn't have any spares) find a USB2 back-to-back power cable (i may > have made one by cutting a plug off a USB device and wiring it to a > 5.0v supply), plug it into one of the USB2 ports and provided "direct" > 5.0v power that way. you *need* a stable supply to do that (1.5 > preferably 2.0 A) designed *specifically* for providing USB power. > UNDER NO CIRCUMSTANCES plug the 12v PSU into the USB socket. and DO > NOT use an "off-the-shelf generic 5.0v wall wart". use something > SPECIFICALLY designed for providing USB power because it is (a) stable > and (b) current-limited. 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. Can I use one of them with a standard USB 2.0 USB A to USB A (male to male) cable? The term 'back-to-back' power cable yielded limited search results in my case. Another option is an official PSU for the Raspberry Pi, 5V, 2A with wall plug and a non-detachable micro-usb cable. I can buy a micro-usb to USB A adapter if this is going to work. So I have to either buy a cable, an adapter or a whole new USB Power supply depending on your opinion. > if you plug the Card directly into a socket (OTG, removed from the > MicroDesktop) - not via a USB hub - "ls" should show the familiar USB > ID for the A20. My initial thought today was: "NO, now everything is lost." so your reply made my day. Tested the Card standalone and 'sunxi-fel version' shows an Allwinner Device in FEL-Mode. Computer Card still alive! Pablo _______________________________________________ arm-netbook mailing list [email protected] http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to [email protected]
