I am trying to switch on the board (LIME2 A20 ). I can get 5V at 5V test point but there is no Volatge on 3.0VA and 2.5V test points. The IPSOUT from AXP209 gives 5V.
There is nothing on the debug UART!
I have been trying to debug. Here are some details
AXP is powered by ACIN using 5V,
IPSOUT is 5V,
LDO1 gives 1.2V,
LDO2 and EXTEN are 0 V!
What source of 5V do you use?
When measuring, make sure you have nothing at all connected other than power.
(Definitely no debug uart etc.)
Also, no SD card.
Good quality PSU, not some cheap thing.
John
Quote from: Anton_A on January 26, 2016, 07:55:16 AM
What source of 5V do you use?
I am using a 3Amp rated supply. Seems not to be a cheap one. And another olimex micro A20 board would work properly on the supply!
I tried to use a Bench Power Supply with enough current limit. Still no luck.
The board will use just a few milli Amps at start or when I press the reset button. and then is almost zero!
Quote from: JohnS on January 26, 2016, 09:44:13 AM
When measuring, make sure you have nothing at all connected other than power.
(Definitely no debug uart etc.)
Also, no SD card.
Good quality PSU, not some cheap thing.
John
I haven't connected debug UART. uSD was present there.
Maybe some components are destroyed in 2.5V and/or 3.0V curcuits.
What resistance is between points 2.5V and 3.0V and GND? I obtain near 14 kOhms and 17 kOhms