yoga 700 14isk 5v problem

[reassor]

Hey all.
Got wierd problem. Starting to think that EC do not want to power on 5v for some reasson but according to schematic there can be 0ohm resistor used which is not presen on schematic.

Ec sends 2 signals ec_on and ec_on_5v

Both have +3.3v but on my board ec_on_5v does not always reach buck converter second enable.

its SY8286CRAC

can i jump ec_on to ec_on_5v ?

Or do i need to reball this bs ? :O

When i touch around buck converter it starts. Replaced all junk around it.

[reassor]

Re: yoga 700 14isk 5v problem

Check the picture.
There is no resistor there and lines are not connected.

[mcplslg123]

Re: yoga 700 14isk 5v problem

Try putting 0 Ohms on PR210 and cut the track on PR212. make sure not to cut too deep and check whether the line is disconnected by checking with DMM on buzzer mode. Here, by design, the Enable can be either EC_ON or EC_ON_5V-so you can use either of them.

[reassor]

Re: yoga 700 14isk 5v problem

Try putting 0 Ohms on PR210 and cut the track on PR212. make sure not to cut too deep and check whether the line is disconnected by checking with DMM on buzzer mode. Here, by design, the Enable can be either EC_ON or EC_ON_5V-so you can use either of them.

did that got 5v on pu202 but that ec_on line fell to 2.8v ...
when i jolt it with 3.3 everything starts... dunno how to safely make it

Lifted ec - reballed, removed mod and works ... for now. will see. Im hopefull

Didnt have schematic so i was working from 5v buck converter datasheet. And there is mode selection which here is used as second enable... Thats why i was so confused that there is nothing *voltage wise*. Adding to confusion moving finger around that "mode selector" made voltage show up on 5v coil.
When i asked about this "jump" i was so focussed on sending 3.3v there that i didnt think why its not there. Typical thinking in circles

After i found schematic here (forum) and seen its all EC i decided to just lift the bastard.

Thx and sorry for confusion.