MacBook Pro 2015 unknown issue

[mkhtz]

Hi folks! I'm a proud owner of a 2015 MacBook Pro that I got about 2 years ago. I got it for free from a client (I do tech repairs) who spilled coffee on it... She didn't want to wait for it to be repaired so she gave it to me and bought another.

I disassembled it and cleaned it with isopropyl alcohol, putted it back together and it worked... For a year. Since about a year the screen on it started to flicker, which wasn't much of problem for me at the time since I used an external monitor. But now it's also flashing on the external screen! The continuous flashing (see attached video) makes it impossible to use.

So far, I've tried :

- NVRAM and PRAM resets
- various software upgrades
- reformatting the Mac
- taking apart the logic board and cleaning all connectors
- taking apart the IO board and cleaning all connectors
- replacing the thermal paste and main fan

And NOTHING worked. This is driving me absolutely crazy, I'm one step from burying it in my backyard. I searched the whole Internet and found no forum post or article mentioning the symptoms of my Mac. I assume, now that I've tried every trick up my sleeve, that it must be a hardware issue, but which one?

I must confess I'm not a Mac guy to begin with... I've always worked on PCs, the only reason I use this MacBook is for my home studio. So I sincerely hope one of you experts can help me out on this!

Best regards,

MK

 

[pigoo3]

Since about a year the screen on it started to flicker, which wasn't much of problem for me at the time since I used an external monitor. But now it's also flashing on the external screen! The continuous flashing (see attached video) makes it impossible to use.

I assume, now that I've tried every trick up my sleeve, that it must be a hardware issue, but which one?

Hello MK...sorry to hear about the MacBook Pro issue.

I agree with you...since the flickering is both with the builtin display & an eternal monitor...it probably eliminates issues like:

- A messed up video port problem (loose port or bent pins).
- An internal display cable problem (loose or damaged).
- A bad video cable to the external display.
- A bad builtin display or external display.

It's got to be something that's common to both the MacBook Pro's internal display & external display...which might mean:

- Something to do with the GPU (loose or damaged connection/pin or GPU going bad).
- Overheating somewhere (causing the display issues). But if internal temps are "normal" (below 190F)...probably ok.

Another longshot possibility. Maybe there's a software/OS issue. You can test this by creating a brand new user account...then reboot & log into it. See if this helps. This is sorta like a "virgin/fresh" brand new computer setup.

HTH,

- Nick

 

[mkhtz]

Hello MK...sorry to hear about the MacBook Pro issue.

I agree with you...since the flickering is both with the builtin display & an eternal monitor...it probably eliminates issues like:

- A messed up video port problem (loose port or bent pins).
- An internal display cable problem (loose or damaged).
- A bad video cable to the external display.
- A bad builtin display or external display.

It's got to be something that's common to both the MacBook Pro's internal display & external display...which might mean:

- Something to do with the GPU (loose or damaged connection/pin or GPU going bad).
- Overheating somewhere (causing the display issues). But if internal temps are "normal" (below 190F)...probably ok.

Another longshot possibility. Maybe there's a software/OS issue. You can test this by creating a brand new user account...then reboot & log into it. See if this helps. This is sorta like a "virgin/fresh" brand new computer setup.

HTH,

- Nick

Hello Nick,

Thanks for the quick answer ! Unfortunately I'm unable to check wether the temperatures or normal or not. It seems to heat up quite a lot (and in fact the screen appears to flicker less when the Mac is cold started), but I'm not sure what the normal temp is for a MacBook. I just managed to update it to MacOS Catalina, I'll try creating a new account and logging in that way (if I manage to get access to the necessary menus !).

I also forgot to mention that while the screen flickers it block inputs from the touchpad ! But the keyboard still works fine, and I can use an external mouse that works fine too ...

Regarding the GPU, I guess it's integrated on the main logic board ? So the only solution must be to change the logic board if the GPU has kicked the bucket ?

Best regards,

MK

 

[chscag]

Regarding the GPU, I guess it's integrated on the main logic board ? So the only solution must be to change the logic board if the GPU has kicked the bucket ?

We don't know that unless you can give us the exact model number or serial number so we can look it up. The integrated video chipsets by Intel almost never fail; it's the separate GPU that many of the more expensive MacBook Pro models have that fails. Notably the Nvidia GPUs.

Your 2015 may have dual GPUs but we don't know that without a model identifier or serial number.

 

[iggibar]

2015 retina models had known flickering issues that were normally fixed with resetting PRAM. However, you said you reset it and it didn't resolve the issue. Have you tried alternating color profiles?

Since an external LCD screen can also show flickering, we can rule out backlight flickering issues cause by bad fuse and resistors. This pretty much rules out EVERYTHING on the connection side...which is a bad thing because it points to either hall sensor(lid sensor), or voltage regulators that are probably corroded and shorting. It is common for this issue when liquid is spilled on the keyboard. There's probably a 1% chance of the issue resolving itself without an expert repairing your board.

 

[chscag]

He stated that the flickering also occurs on an external monitor that he has attached. That would lead me to believe it is GPU related.

 

[krs]

Does Catalina still offer widgets?
Question came up how to measure temperatures - I use iStat which provides the current temperature of a number of internal Mac components

 

[chscag]

The Widgets have been gone for awhile now. I don't remember if they were removed before Mojave or maybe Mojave. They are gone in Catalina for sure.

 

[pm-r]

Does Catalina still offer widgets?

Nope!! Dashboard, the app that used them is a 32-bit app, so they died if they hadn't done so previously, already.





- Patrick
======

 

[krs]

OK - so what replaces them on Catalina - or on the macOS where they disappeared?

I only use a few, but are they ever handy.

PS: Answered my question as far as Mojave is concerned:
Get Dashboard Working Again in macOS Mojave

.........but for Catalina they just disappeared?

Dashboard was a macOS feature - so why did that not get ported?

 

[pm-r]

Dashboard was a macOS feature - so why did that not get ported?

Because Apple said it was an end of life time, and because they can do that!!! Besides it was quite a resource hog anyway IMHO, considering what little it did.

As I understand it, most old widgets have more modern day replacements available, they just work differently and don't rely on the old Dashboard.app.





- Patrick
======

 

[krs]

Any idea what one would use to replace iStat?

It provides a nice summary of various system parameters - temperature of the various components being one I frequently refer to

 

[MacInWin]

iStat puts icons on the top bar now. Works on Catalina just fine.

 

[techiesteve]

Regarding the GPU, I guess it's integrated on the main logic board ? So the only solution must be to change the logic board if the GPU has kicked the bucket ?

MK

Based upon the info supplied it's likely, if economically viable, you will need a replacement logic board.

When you clean up a logic board with a stiff anti static brush and IPA, some will run under some IC's. This is obvious if you use an air blower to dry the board, you will see the air forcing the IPA out from under IC's. This shows the original liquid spill could also have gone under IC's, and could not be brushed/cleaned off, so can cause failures months or even years down the line. Cleaning up a logic board liquid spill can never be a 100% reliable fix.

 

[pm-r]

Any idea what one would use to replace iStat?

As Jake mentioned, it seems they have a solution that works.

iStat puts icons on the top bar now. Works on Catalina just fine.
- Jake

In such cases, check with the developer site or just crank up your Google search engine.






- Patrick
======

 

[iggibar]

Yes, I know. You have to think of the issues from an electrical flow perspective. It's impossible for a failing/failed GPU(integrated or discrete) to cause problems with the trackpad the way the OP mentioned. There's no I/O from the trackpad that is controlled by the graphics chip. However, there are resistors and capacitors that have either direct paths to both, or have a path connected by a channel/voltage controller. If I were to place a bet, I'd bet 50/50 it's either a capacitor that shorted and has a cracked connection, or a resistor that might have shorted and is allowing too much current to get to a controller and send false signals to hall sensor(lid sensor). Ironically, the hall sensor is also responsible for causing issues with the trackpad.