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820-3787 A1398 -- Keyboard and Trackpad issues.
- Thread starter ALB-Repairs
- Start date
ALB-Repairs
Member
If i recall correctly i had a functioning keyboard in boot menu with the original keyboard controller however since replacing the keyboard controller it is not (as said above this could be a false negative because they stated the keyboard only worked sometimes)
I dont believe the keyboard is recognised under devices in OSX.
Thanks
I dont believe the keyboard is recognised under devices in OSX.
Thanks
ALB-Repairs
Member
No
The SMC reset keys and power button do work though.
it just booted halfway, shut down and now has quarter fan spin. I havent done a PCH on one of these before, lets hope its just EFI failure.
The SMC reset keys and power button do work though.
it just booted halfway, shut down and now has quarter fan spin. I havent done a PCH on one of these before, lets hope its just EFI failure.
SMC reset and power button is a separate circuit. If the keyboard/trackpad is not listed under USB devices something is up with U4801, check all power to that chip and the 2 USB lines. Only thing it need to be listed in OSX is power and USB.
Quarter fan spin now is probably some corrosion somewhere.
Quarter fan spin now is probably some corrosion somewhere.
ALB-Repairs
Member
The laptop has no corrosion or signs of liquid ingress so i somewhat doubt there will be corrosion. Everything to U4801 has been tested, all VIN and power rails.
I can confirm the SPI rom has been checked and re-written with a confirmed good ROM and we are still getting quarter fan spin.
Zac
I can confirm the SPI rom has been checked and re-written with a confirmed good ROM and we are still getting quarter fan spin.
Zac
ALB-Repairs
Member
I eventually got around to fitting a new PCH and clearing up the ME region. I changed the PSOC, fitted one from a 820-3536 board, after i noticed the USB datalines not having any real data passed through them.
I now how trackpad movement, click and everything seems great, other than the middle row of keys not responding atall.
From experience i know this is usually the PSOC chip.
Im starting to get concerned, i seem to be destroying these chips super quickly and easy. Im starting to guess they are fairly heat sensitive or pressure sensitive, i think i just need to be a bit more careful when soldering them and i should have a working laptop
I now how trackpad movement, click and everything seems great, other than the middle row of keys not responding atall.
From experience i know this is usually the PSOC chip.
Im starting to get concerned, i seem to be destroying these chips super quickly and easy. Im starting to guess they are fairly heat sensitive or pressure sensitive, i think i just need to be a bit more careful when soldering them and i should have a working laptop
ALB-Repairs
Member
Sorted that all out now. I really need to get a new handpiece for my T210m JBC iron.
Now i just need to get the laptop tested with the new ME region and ensure it doesn't do anything undesirable. The laptop now passes the inbuilt diagnostics though.
Now i just need to get the laptop tested with the new ME region and ensure it doesn't do anything undesirable. The laptop now passes the inbuilt diagnostics though.
ALB-Repairs
Member
I will do, i need to redownload ASD. I dont think the inbuilt diagnostics check the ME but i cant really remeber. The fans do however ramp up when the machine gets warm.
The main concerns are that
1: I took the ME from a 3476 id already cleaned, knowing that they run on similar platforms. I cant remeber where i obtained the ME that is in my 3476 BIN.
2: When the machine starts up there is maybe a 5 second delay before it starts its power on sequence. When running of my bench supply i notice that it pull 0.2A then back to 0.034, then after a few seconds pulls more current and the fans spin up.
3: Seems to boot slower than it did when it came in.
Anyway, ill try get ASD ran on it and keep the thread updated.
The main concerns are that
1: I took the ME from a 3476 id already cleaned, knowing that they run on similar platforms. I cant remeber where i obtained the ME that is in my 3476 BIN.
2: When the machine starts up there is maybe a 5 second delay before it starts its power on sequence. When running of my bench supply i notice that it pull 0.2A then back to 0.034, then after a few seconds pulls more current and the fans spin up.
3: Seems to boot slower than it did when it came in.
Anyway, ill try get ASD ran on it and keep the thread updated.
ALB-Repairs
Member
I know that. Sorry i didnt explain myself well enough. Its a clean ME region that ive used to clean a 3476 Bios. I did check all settings with FIT and moved the region using HxD. Ive been correcting ME regions for a while now but i do need to double check this ME build is supported by this chipset platform.
EDIT: Just got it running ASD and can confirm the ME region is still messed up. Back to the drawing board for a little bit.
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