Hi, i got to repair lenovo yoga 910 with mainboard nm-a901, found the isl9237 burnt, changed already 2 ic's, no 20v, only 5v. Can't find the reason. All resistor values seems fine.
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Lenovo YOGA 910-13IKB No 20volts
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Re: Lenovo YOGA 910-13IKB No 20volts
Originally posted by Lukosiukas View PostHi, i got to repair lenovo yoga 910 with mainboard nm-a901, found the isl9237 burnt, changed already 2 ic's, no 20v, only 5v. Can't find the reason. All resistor values seems fine.
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Re: Lenovo YOGA 910-13IKB No 20volts
Translate this it may help to understand the working condition of USB-C on this board,20V can`t be generated until all other conditions are met.
https://www.chinafix.com/thread-1201120-1-1.htmlLast edited by SMDFlea; 07-17-2020, 05:48 AM.
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Re: Lenovo YOGA 910-13IKB No 20volts
Originally posted by SMDFlea View PostTranslate this it may help to understand the working condition of USB-C on this board,20V can`t be generated until all other conditions are met.
https://www.chinafix.com/thread-1201120-1-1.html
I ordered a replacement chip, hope I will be able to replace it.
I was wondering if the chip is compatible with the ISL95857HRZ that is mentioned in the schematic?
I could not find datasheets, just compact ones that didn't contain proper info.
It's attached for convenience. Does anyone know if this is a common fault caused by something that can be improved?
I'm a complete beginner with reading schematics and understanding electronics and I am trying to learn so I'm very happy with that link, thanks .
MOD Edit: Link to schematic - https://www.badcaps.net/forum/showthread.php?t=81087
If anyone has a boardview version I would be very greatful too. thanks!
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Re: Lenovo YOGA 910-13IKB No 20volts
Hi. See if the attached works for you.
MOD Edit: Boardview moved - https://www.badcaps.net/forum/showthread.php?t=83591
.Last edited by SMDFlea; 08-24-2023, 10:43 AM.
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Re: Lenovo YOGA 910-13IKB No 20volts
hi, thanks a lot, works with the Tebo Viewer 4 from here : http://laptopserviz.bg/media/wysiwyg...T_view_4.0.zip
(even on Linux with Wine and mfc42.dll )
I'm waiting for my replacement PU4 chip, will post here if I have something constructive to add
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Re: Lenovo YOGA 910-13IKB No 20volts
thanks for all the help.
I replaced the isl9237 chip, which was a plain nightmare .
I am unsure if it is actually fully connected, especially for pin 17, because I thought I saw a broken line - I have no microscope and it's seriously hard with a magnifying glass .
I used : https://www.chinafix.com/thread-1201120-1-1.html and the boardview that is posted and the datasheet here for isl9237 to get the points:
https://www.renesas.com/eu/en/docume...9237-datasheet
As far as I understand it, it is indeed PQ10 not going on. It has 5.1 on the input but the gate, which seems to come from pin13 ASGATE.
I have no measurement on that pin with dc plugged in.
If I understand the chinafix link, that seems to be the cause for the pq10 not opening?
I am struggling because I am way of my league and the boardview is not as intuitive as openboardview based ones.
Can I test if this is the issue by injecting voltage after Pq10 and if so where and how much?
My VDD and ACIN (pin 18,17) seem to have only 4V, is that the cause of the issue?
I'm a bit stuck now, but perhaps this answers @galleria1313 's question?
Can anyone help me on how to proceed? thanks a lot!
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Re: Lenovo YOGA 910-13IKB No 20volts
studied a bit further. It seems PQ10 does get 5.2 in and out, it was bad measurement I think. Again looking at the chinafix link, it seems VIN needs to be 3.3 V for the board to start at all, is that correct? And if that comes from pin 26 on PU4 there may be my issue.
Pin 26 is 0 and so is VIN for PQ19 . In my schematic I see U101, is that PQ16?
Unfortunately I don't understand it all well enough to know how to continue. I am happy to do measurements if anyone has suggestions. I thought about putting 3.3V on VIN and see what happens?
I don't understand the translation of the link well enough to understand the process completely...
oh, and my PR53 is about 0.52V, PR57 is about 5.2. As I understand it, PR53 should be 3.3V as the VIN for PQ19.
Would be great to get a confirmation that it's save to inject that and with how many amps.
any help and tips are appreciated
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Re: Lenovo YOGA 910-13IKB No 20volts
I have also such a Notebook, which is completly death. The ISL9237 is also burnt, it's visible with the eyes.
I hoped I can change the ISL9237 and everything is ok. But what I read here, there are more problems... Has anyone find out more, what was the real reason??
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