MacBook Pro 15" Mid 2014 Fans Spin No post

[Stephen]

MacBook Pro 15" Mid 2014 Fan Spins for 10 seconds then shuts off then turns on again.

The computer needed a new battery and we installed the new battery to finally get to install a NEW OS on a new ssd. The computer was installing the OS then we walked away from it. We walked back to the computer and it was turned off. So we decided to see why it was off, we turned it and it didn't post. Remember this was a fresh new OS install of Mac OS Mojave. We looked to see if the fans turned on and they did. We are leaning towards maybe a failed bios chip but its odd that it was working perfectly until we installed a new OS. Maybe we are missing something here. We can solder and repair but currently we do not have the board schematic atm. If you have any suggestions and also the BOARD schematic and PDF please provide it as well! We will be grateful to those that suggest anything! Would hate to purchase a logic board when this one was working perfectly fine.

[piernov]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

The macOS Installer can perform a BootROM update as part of the installation process. It's rare, but corruption can happen and in this case you have to flash EFI with an external programmer.
Schematics and boardviews are most likely already posted for both the IG and DG models.

[Stephen]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

So basically new BIOS chip as expected?

[Stephen]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

Replaced the Bios chip with a new Bios Chip programmed for this model. Still has the 10 second fan spin SHUT OFF then spin again. No post no screen display. Any suggestions here? Is there something I should be looking for? The board turns on and like stated the computer was installing a new OS (Mojave) and it failed to install and turned itself off and it never turns on again. So the next step is find out what you guys think it may be. Any suggestions would be great or Logic board level repair suggestions as well and where to look at on the board view/PDF files. Thanks again!

[Stephen]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

BUMP any help would be greatly appreciated!

[Stephen]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

One more bump! Need a little help here.

[Weelcup]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

Can you upload the bios dump. The original one.
Also the board number. I.e. 820-xxxx.

[dellxps15]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

when pc is cold, it turn off always after the same time when pc is getting hotter ?

what was the cause of this malfunction? water spill... fall damage... nothing ?

board code ? could be that tantalum capacitors failing ? check voltage on that small tantalum capacitor ( board code would help to see if they suffer from that problem) and check voltage when it tutn off ...

[piernov]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

Board model number is 820-3662 for IG or 820-3787 for DG. No tantalum capacitor failure on these.
Symptoms and history were described in original post.

[dellxps15]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

volts on L8710?
edit: try boot with battery only... then with psu only and see if still turn off.

[Stephen]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

Hey Dellxps15,

We have tried to boot without battery and with. like stated in the original post the computer booted and wouldn't post past the Apple Logo when trying to get a os loaded to install a new os on the SSD. The battery was the culprit originally. We installed a new battery (OEM) and it booted into the USB OS (Mojave) and we were able to start installing a new OS. We walked away and then the computer was shut off. We tried to boot it again and can hear the fans spin. The funny thing is they spin for exactly 10 SECONDS then shuts off then restarts and does it again. No post no nothing. WE went ahead and purchased a new BIOS chip and replaced it...sadly no fix with new bios chip. Computer also had no water damage or spills etc in its history. Just needed a new battery pretty much.

[dellxps15]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

ok, so now u dont have apple logo. can u read volts on L8710 ?

[Weelcup]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

Suspecting bios me region damage.

[Stephen]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

Thats crazy wouldn't a new bios chip fix that issue @weelcup? we replaced it with a new bios chip for this year and model. Odd that it didn't solve it whatsoever.

[Weelcup]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

Thats crazy wouldn't a new bios chip fix that issue @weelcup? we replaced it with a new bios chip for this year and model. Odd that it didn't solve it whatsoever.

Well, how can you guarantee the "new bios chip" is reliable.
If you have a programmer and can program it just send me the the board number and i will send you a bios dump to flash it. It will be very fraustrated if the bios was the issue and we spend all the time to find a hardware issue.

So just to make sure it is not the bios, a good clear dump will judge.

[Stephen]

Re: MacBook Pro 15" Mid 2014 Fans Spin No post

Ok I will take a look tonight. I never had to flash our boards. Usually we just do schematic repairs.