So, having managed to get the emmc working on the switch I was talking about in the “Is this CPU failure thread”, I then set about fixing the less pressing issues on the device. All of which went well. However, as is often the case, I bent a pin in the LCD connector when putting it together.
So, I took a connector off my spares board and swapped it over. What I didn’t notice before attempting to boot it from battery however was a tiny short between two of the pins on the left hand side of the connector.
On attempting to boot it from battery only, I got nothing, and I could feel heat from the LCD connector area. It was only on closer inspection and testing that I found the short. I have now reflowed the connector and no short is present.
With the newly working emmc installed it WAS booting this morning (pre-short). Now I see no response. With the emmc removed, I am able to get it to connect to the PC with the USB in one direction, but not the other. The bad way round the PC knows it has been detected, but shows an error. With it the good way round, I am able to connect to RCM and inject a payload, and it returns 0x7000 as it used to, but I no longer see anything on the screen and the backlight does not come on.
I have checked for shorts in obvious places, including under the CPU, but haven’t found any. All the rails around the PMIC look to match what I would expect. I will continue to do some reading etc, but does anyone know if there is any hope on this one, or where to start?