Lenovo Ideapad Flex 15D Schematic needed

[northpoint]

No power on, No power - Dead.
No visible damage - of course

Stenciled on MB is YA-YA1 94V - 0
E114139
1351
PC-HK Limited

Have been searching and not finding anything. Perhaps its not available or I just need to brush up on my search skills.

Thanks,

Northpoint

[piernov]

Re: Lenovo Ideapad Flex 15D Schematic needed

I don't think there are any schematics. Got a Flex 2 14 and it's the same. Although mine has an excessive current draw on a 3V LDO line due to (I think) an issue with the EC. Injecting 3V makes it boot.

Can you take high resolution pictures of the board?

[northpoint]

Re: Lenovo Ideapad Flex 15D Schematic needed

I don't think there are any schematics. Got a Flex 2 14 and it's the same. Although mine has an excessive current draw on a 3V LDO line due to (I think) an issue with the EC. Injecting 3V makes it boot.

Can you take high resolution pictures of the board?

Have you tried to narrow it down by possibly taking a can of 'Freeze spray' and seeing where it heats up first? That might be an option.

https://www.amazon.com/MG-Chemicals-...16f634759a5e96

Ive never done it but have seen it done. Would be curious if that showed something on your board.

Just a thought

[piernov]

Re: Lenovo Ideapad Flex 15D Schematic needed

Oh yeah I use alcohol to narrow down the heat. In this case the alcohol evaporates a bit faster on the EC when it's powered so it heats up a bit. The EC usually doesn't heat up so that's why I suspect it. I'm waiting for the replacement to arrive.
In my case the 3.3V line was pulled down to 2.85V, prevent the computer from turning on. The line draws 200mA but the LDO can only supply as much as 150mA.

[SMDFlea]

Re: Lenovo Ideapad Flex 15D Schematic needed

I don't think there are any schematics. Got a Flex 2 14 and it's the same. Although mine has an excessive current draw on a 3V LDO line due to (I think) an issue with the EC. Injecting 3V makes it boot.

Can you take high resolution pictures of the board?

If you do replace the EC the last post on this ******* topic may be useful

http://*******/viewtopic.php?f=58&t=51754

English translation Quote: I confirm I replaced NPCE285GA0DDX with NPCE285PA0DX it all started, did not sew anything

EDIT: Never mind,i see youve ordered a replacement

[northpoint]

Re: Lenovo Ideapad Flex 15D Schematic needed

Oh yeah I use alcohol to narrow down the heat. In this case the alcohol evaporates a bit faster on the EC when it's powered so it heats up a bit. The EC usually doesn't heat up so that's why I suspect it. I'm waiting for the replacement to arrive.
In my case the 3.3V line was pulled down to 2.85V, prevent the computer from turning on. The line draws 200mA but the LDO can only supply as much as 150mA.

Found the correct info on the board:

Lenovo IdeaPad Flex 15D 20334 AMD Motherboard DAST6BMB6C0

So, I dont have to post a pic unless you want me too.

I do believe I found a schematic for the board. However - $$ to become member of site to download it.

https://***********/threads/dast6bmb...75/#post-52202

Hope its ok to post the link. Dont need any trouble

[piernov]

Re: Lenovo Ideapad Flex 15D Schematic needed

Quanta ST6 is available on sualaptop365.

[northpoint]

Re: Lenovo Ideapad Flex 15D Schematic needed

I finally got my hands on the schematic for the Lenovo Flex 15 . I was looking thru the power supply section and taking some measurements under power. Started looking at the mosfets and noticed that some of the stenciled part numbers on the board are not listed in the schematic. This kinda brought things to a halt because its difficult to find where in the schematic certain components are located.

So, This brings up a good question. Are schematics for the major producers of MB's just a general guide and then someone like Lenovo goes and makes undocumented changes or do I just basically have the wrong schematic?

For instance, Mosfet location on the MB is called PQ81 but in the schematic its not there. Its not just one, Its several. Is this common to run into?

The only reason I am spending time on this board is to sharpen my troubleshooting skills. It was donated by a customer and I wanted to have a go at it in my spare time.

Opinions welcome...

NP

[BlueMidnight]

Re: Lenovo Ideapad Flex 15D Schematic needed

All the schematics I can find are the same, and they are all for the ST6A (Flex 14/15). The ST6A is an Intel board.

Your board is an ST6B (Flex 14D/15D). The ST6B was released the following year and is an AMD board.

They are extremely different.

You can still do troubleshooting without a schematic. You just need to have studied other boards and schematics to know what to expect. You can also find datasheets for many of the chips on the board. The datasheets may contain schematics showing how the chip should typically be used, and actual motherboards often stay pretty close to that.

[northpoint]

Re: Lenovo Ideapad Flex 15D Schematic needed

All the schematics I can find are the same, and they are all for the ST6A (Flex 14/15). The ST6A is an Intel board.

Your board is an ST6B (Flex 14D/15D). The ST6B was released the following year and is an AMD board.

They are extremely different.

You can still do troubleshooting without a schematic. You just need to have studied other boards and schematics to know what to expect. You can also find datasheets for many of the chips on the board. The datasheets may contain schematics showing how the chip should typically be used, and actual motherboards often stay pretty close to that.

Hi BlueMidnight,

I want to thank you for replying. Yep. I learn as I go I guess. Even though I might stumble along the way I will pick this up and learn from my mistakes.

Thanks for clearing that up for me.

NP

[fickit1time]

Re: Lenovo Ideapad Flex 15D Schematic needed

I finally got my hands on the schematic for the Lenovo Flex 15

Could you please ad the schematic so others like myself can use it.
I've also have an issue with the lenovo flex 15d motherboard.
Appreciated.