Need Schematic Lenovo Yoga 720-13IKB LA-E551P REV 2.0
I have a short measured from a coil and some surrounding caps. So far I am ASSUMING its a 5v circuit.
I have battery charge light.
I have battery and power light.
Battery charges to full (8v) no problem.
Power button responds with power light coming on.
No power up from board.
What is crazy is I cannot locate the 19v rail in this thing. I know its there or I would not have the other rails. I do have a short on a circuit that I assume is a 5v rail. Short to ground...
northpoint
Member
Last Activity: 12-07-2020, 11:48 AM
Joined: 12-14-2012
Location: Osceola, Indiana
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Re: Lenovo Ideapad Flex 15D Schematic needed
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...Leave a comment:
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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...Leave a comment:
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Re: Lenovo Ideapad Flex 15D Schematic needed
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.
[url]https://***********/threads/dast6bmb6c0-rev-c.26675/#post-52202[/url]
Hope its ok to post the link. Dont need any trouble
Re: Lenovo Ideapad Flex 15D Schemati...r />
Found the...
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Re: Lenovo Ideapad Flex 15D Schematic needed
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.
[url]https://www.amazon.com/MG-Chemicals-Super-Spray-Aerosol/dp/B0047Y9DKS/ref=as_li_ss_tl?s=industrial&ie=UTF8&qid=1483251191&sr=1-2&keywords=freeze+spray&linkCode=sl1&tag=ipareh-20&linkId=14d54680eb8f9320f716f634759a5e96[/url]
Ive never done it but have seen it done. Would be curious if that showed something on your board....Leave a comment:
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Lenovo Ideapad Flex 15D Schematic needed
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 -
Re: Openflex Boardview: New boardview software (linux, windows and OSX)
Getting compile error on Linux Mint 17.2 so, I guess I have to upgrade to 18 for the newer gcc. Ill do that tonight probably
GCC version needs to be >= 4.9
Im excited to try this out thank you....
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Re: Sourcing Transistors
It was both channels. But after a resolder they started working. See my earlier post.
Learning all the time - thank you.
...
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Re: Sourcing Transistors
Getting 23Vdc on each coil (there are two relays in this model). Incidently, I took the relays out to look them up and when I put them back in it starts to work now. Cold solder joint?
Everytime I spend hours on a problem and finally decide to post I seem to answer problems myself or find them easier. I always seem to come off foolish.
Thanks for your reply....Leave a comment:
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Re: Sourcing Transistors
Just wanted to top off this post with an update. This is the first amp that I have ever repaired. I am almost done with it. Its actually has a 5A relay that is bad. After turning it on I have to tap it with my screw driver to get it to click over and drive the outputs. lol.
The relay is no longer available wouldnt you know - VB 24SMBU-522 . I do believe this is a good replacement for it:
[url]http://www.mouser.com/ProductDetail/Fujitsu/FTR-F4GAK024T-KW/?qs=%2fha2pyFadujHs2MorhmqsVbrQp0UHvi%2fIwLCctxW9Yywm2Kyw%252bK9FQ%3d%3d[/url]...Leave a comment:
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Re: Computer Power Supply Antec EA-500
Dont forget the amount of glue they use to cover all the important "easy blow" components.
I say check em when it dies.Leave a comment:
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Re: Sil-pads question
Just want to cover all the posts and thank everyone for replying:
I feel stupid. I ordered in some transistors - C1864 / A4886 to finish off a car amp. I did not notice that the had a bare metal backing. So, When I tested the amp out of the case it basically ran fine in initial power on tests. So, I assembled into the case and noticed a large current drain and voltage drop. I took it out and tested again and it was fine.
So, What I had done is not notice that one of the transistors was different than the others in that its packaging...Leave a comment:
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Re: Sil-pads question
The answer to this is yes. You must isolate the transistors from the heatsink because the metal backing on the transistor is not isolated from the pins on the transistor. This is what is probably causing the amp to suck up 6amps when put in the case. The case is acting like a big heat sink and has the heat sinks from transistors attached to it. Not a good thing. But now I know.Leave a comment:
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Sil-pads question
Finally got a Kenwood KAC-927 amp fixed up. Had to replace the output transistors in it and clean it up a bit. At idle it seems to draw 1A and the led does change from green to orange- which on this model means its ready to go. However, When putting the aluminum case back on and powering it up it immediately spikes the current and accordingly a voltage drop. I am thinking about the power and output transistors have no sil-pads on them and thus the collectors might be shorting out with the heat sink and case. There was a lot of heat sink compound on the heatsink where they meet the case and where... -
Re: Look what a customer gave me
Ive had several customers just plead with me to look at their inkjet printers as they have quit putting ink on the paper all together - brother and epson. I have repetitively told them that they are not worth looking at and to invest in a laser printer instead. But they are continuously loured by the cheap price on inkjet printers and hardly ever take my advice. They seem to only look at the short term and spend their money on these cheap printers and never understand how much they are spending buying new inkjets all the time compared...Leave a comment:
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Re: Sourcing Transistors
Thank you very much. The kenwood suffers from a no power condition and I tested the C4886 by taking it out of circuit and I get basically about .375 whether I test with the lead base positive or negative. Since this is a NPN type I get the following results:
Using multimeter in diode mode:
Base Collector emitter
pos 326 327
neg 320 320
emitter to collector: 000 (either way with leads) shorted?
My testing shows its bad.
...Leave a comment:
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Re: Sourcing Transistors
I want to thank you both for helping me understand. I do have some background in electronics but I have not been doing board level work in years. So, I have to basically learn a lot of things over again. Especially finding sources for stuff. It does get a bit confusing at times and I am glad your both here to help clear up these odd points.
Thank you so much for all the advice. It is very much appreciated!Leave a comment:
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Sourcing Transistors
I have a question about getting replacement transistors. I run into this a lot and would just like some clarification.
So, If I have a bad transistor - lets say the packaging on it says LAPT C4886. I have the hardest time trying to find it from component suppliers like mouser. I eventually find it under another part number 2SC4886. Now I have to wonder - Is this a pin-for-pin direct replacement just under a different part number? Why cannot I find a data sheet for the LAPT C4886 on the chip to make sure? Can I trust the 2SC4886 to be a direct replacement? How would one know if... -
Re: Fosgate Prime R500-1 car amp
Well, I have retested the transistors and they tested fine. I do not have a power supply for it available until friday when my new one arrives. Then I can get more into it. However, I wanted to kinda get a jump on it by testing the transistors. I incorrectly tested them the first time and thats all on me.
On the origional pic in last post on the right side are the transistors that were in question. I see now that its a push/pull circuit setup. Below is a pic of the transistor I was testing. There are 4 of them and...Leave a comment:
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Re: Fosgate Prime R500-1 car amp
Im glad you asked. This made me go back and recheck my work and I screwed up. They are bi polar and are PNP not NPN. Makes a bit of a difference in testing.
Testing - I am using a DMM to toggle the gate (base) on and off. Checked the emitter and collector basically the same. Perhaps I have the testing wrong and I will head back to the books too. sorry.
I am learning.
Pics of board and transisters from my cell phone cam:...Last edited by northpoint; 08-10-2016, 12:52 PM.Leave a comment:
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