Hi,
have a Macbook Pro in front of me where the right option key isnt working. Changed the Keyboard/Topcase and the new one doesn't works, too.
In the schematics it only shows a Left_Option_Key line so is the right option key even supposed to work on this model?
Can anybody give me a hint what the problem should be?
Thanks in advance
lctrbrt
Member
Last Activity: 03-15-2024, 05:31 AM
Joined: 03-20-2020
Location: Potsdam, Brandenburg
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Right Option Key not working (Macbook Pro A1398)
Last edited by lctrbrt; 03-31-2022, 03:42 AM. -
How/where to get Samsung (A51) part values?
Hi,
can sombody tell me where I can see the values from the parts of Samsung smartphones? Have a A51 schematic but there's only a part number f.e. C6014 but nowhere in the schematic is a list or a circuit diagram where I could take the valuse from.
Thanks in advance. -
Re: 820-3437-B No PP5V_S5
Hi guys
Sry I forgot to post about the results.
Device is working again like a charme. I did like Piernov told and watched some videos from Louis Rossmann and in one he mentioned that the problem also could occur if the connector for programming the board(I think it was J1800) is corroded and it was. After removing it an cleaning the pads the machine started. THe only problem was that after running it for some hours the backlight would went of but there it was just some dirt under the diode arround teh LCD connector.
...Last edited by lctrbrt; 09-06-2021, 07:20 AM. -
replaced iPhone X touchscreen fails after 2 days
Hi,
bought an iPhone X and replaced the screen. Everything worked fine but after 2 days of using there's an area/line on the right side where the screen is unresponsible. The screen then is defect because the error also shows up with a screen tester.
The strange part is that if I replace the screen with a new one it will work but after 2 days the problem returns with the new screen.
The screens I used where from JK. Anybody knows this and can tell me what it could be? A freind of mine who is way better in boardlevel repairs told me he has no clue because... -
Re: 820-3437-B No PP5V_S5
I've seen so many videos of him unfortunately I don't do stuff like that often cause our shop is relatively small and mostly we do assemblies so I don't can use the 'learned' stuff regulary and forget it unfortunatley. Also I recognize stuff better which is written down than from videos.
When I try stuff like this I inform the customers that I'm just a beginner and that I can try but that this is mostly for learning and if they want I could send it to a partner which is specalised in boardlevel repairs.
But I'll...Last edited by lctrbrt; 07-16-2021, 09:32 AM.Leave a comment:
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Re: 820-3437-B No PP5V_S5
Hey,
no I didn't replace it. The first thing I've learned is like piernov mentioned not to randomly replace parts. The IC looks good and the liquid doesn't came to the area of it so I guess its fine and the problem lies somewhere else.
I took out the board so the SMC should be reseted but no signs of life.
The only thing I replaced was the burned backlight IC but unfortunately no difference in board behavior.
Thank you very much and have a nice weekend...
Last edited by lctrbrt; 07-16-2021, 09:26 AM.Leave a comment:
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Re: 820-3437-B No PP5V_S5
Hi,
thank you very much.
I'm a bit confused about that PPBUS_G3H = 8,19V thing.
I've used the [URL="https://logi.wiki/index.php/Power_Rail_List"]power rail order list[/URL] and there it states that the PPBUS_G3H should be around 12.6V but on the [URL="https://logi.wiki/index.php/PPBus_G3H"]https://logi.wiki/index.php/PPBus_G3H[/URL] site it states that the Air's have to be around 8.6V.
So 8.19V should be ok, should'nt it?
Also is there a quick way to check if...Leave a comment:
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Re: 820-3437-B No PP5V_S5
Thank you very much.
I changed U7701 and no change but the one that was on the board before was definitly fried; half of the chip is black and the housing disintigrates if I scratch slightly with tweezers on it.
I'll have a look at U7501, hopefully it will resolve the problem.Leave a comment:
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820-3437-B No PP5V_S5
Hi at all,
I got an Macbook Air (820-3437-B) with liquid damage which wont turn on.
[B][U]"G3Hot" Rails [/U][/B]
PPBUS_G3H = 8,19V
PPBUS_S5_HS_COMPUTING_ISNS = 8,19V
PPBUS_S5_HS_OTHER_ISNS = 8,19V
PPDCIN_G3H = 16,69V
PP3V42_G3H = 3.44V
PPVRTC_G3H = 3.44V
[B][U]"5V" Rails[/U][/B]
PP5V_S5 = 0V
U7701 is in that area where the liquid was and looks some kind of black/burned.
My Questioin is where PP5V_S5 is generated and if U7701 could be the problem which I... -
Posted in wrong Forum
Hi All
unfortunately I was posting something in Desktop devices forum which should have be posted in Laptop devices...
How can I change this?
Thanks in advance
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820-3332-A Fans on Fullspeed
Hi,
have an Macbook Pro in front of me where a cap was shorted. It was one of these big ones where PPVIN_S5_HS goes in and I changed it.
The board now starts again but the fans run on full-speed and a PRAM reset didn't help.
Unfortunately I don't know the working principles of the thermal sensors. I guess there is some problem with U5550 or the circuit its connected to.
Is there anybody who can give me a hint for what I should look for.
Thanks in advance and have a nice day. -
Re: 820-00138-A Backlight IC
It didn't work😅
I send it to somebody else and guess I've to learn a little bit more but anyways, many thanks for our help I'll surely will annoy you in future
Leave a comment:
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Re: 820-00138-A Backlight IC
Hi again,
so yesterday evening I reread/-watched the tutorials from Jessa Jones and Louis Rossmann and there they told that if measuring in diodemode that the majority is using red on GND and black on the Part/pad which is to test and thats why I used to do it this way.
Beside that I took my cheap 5 bucks DMM and made a list with all readings from the pins. The other(hexagon 340A) one also works but there are the numbers slightly different(less).
Here's the list:
[CODE]
Pin1 OL | Pin13 OL
Pin2...Leave a comment:
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Re: 820-00138-A Backlight IC
Okay, I'll have a look tomorrow.
Maybe my multimeter sucks but I extra take a expensive one, the Amprobe Hexagon 340 but I'll test tomorrow with another one if the readings are the same.
Again I really have to thank for your patience and help. If you sometimes in Berlin then tell me, I'll thank you personally
Leave a comment:
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Re: 820-00138-A Backlight IC
Sry for that. I not only reversed the probes, I also used the wrong ones. The tips where to fat so shame on me����*♂️
Short-Test:
If I put red on pin8 and black on Gnd I got a reading OL
Then if I put black on pin9 I got 0.000
But I dont understand why at the second measurement I supposed to put black on Pin9? Sry if thats a dumb question but if I test continuity shouldn't I also place red on pin9 and black on ground?
Somehow, the tut's where I read...Last edited by lctrbrt; 09-21-2020, 09:27 AM.Leave a comment:
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Re: 820-00138-A Backlight IC
Here's the other picture with line from pin 9
...Leave a comment:
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Re: 820-00138-A Backlight IC
Hi,
sry had to assemble some iPhones so I couldn't answer on Saturday.
The 2 Pins aren't shorted it looks only because of the bad picture quality. If i measure them the DMM shows OL.
I measured up the red line from your picture but somehow there is only continuous at the other side of that cap than your picture shows.
Here's a picture with diode mode readings from that pin '8' and where I think the line goes. I do a next one for pin9.
...Leave a comment:
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Re: 820-00138-A Backlight IC
Unfortunately I dont have any history for that device but I bet there was a prior repair because there was flux all over that area not cleaned very well and I also didnt not clean it before taking picture so it should be flux. I dont see any corrosion or anything in that area under the microscope.
The connection in that hole where I think its pin 9 has a reading of 0.424 and the one under which I consider pin 8 has a reading of 0.563 so I guess my assumption is wrong and I should put UV-solder-mask on that whole and jumper pins from other...Leave a comment:
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Re: 820-00138-A Backlight IC
I dont have a camera here but didn't forget the USB-Microscope which is anything else than decent
Here is a picture but not really good one. There you see the small 'hole' at pins 8-9.
Also there are connections in the board; 2 contacts and I think that they where connected to the ripped/burned pads so it should be possible to jumper from there(I hope)
Here's the picture and I also figured out that I have the right driver IC which should be called: 'LP8548B1SQ_-4'
...Leave a comment:
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Re: 820-00138-A Backlight IC
That was the *.brd I was using and instead of ordering and soldering the IC U7701 I stupidly ordered the U7750 and soldered it.
Dont have a camera on my microscope but will try it with an usb microscope tomorrow if I aint forget it at home 😅
Many thanks ✌️Leave a comment:
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