A2141 not booting

[uintaelectronics]

I have an A2141 that negotiates 20V, pulls 3 amps when off and 4 amps when I press the power button. Fans spin but the macbook does not boot. The backlight does not come on either. Capacitors on the backlight line all have kohms of resistance. I got it to chime a few times but no image. Is this fixable or should I not waste my time?

 

[2informaticos]

First of all, welcome to the forum!

Any fault history available?
What is CPU core voltage (L7211) after 10-15s?
Caps Lock LED reacts?
Did you test external video?

 

[uintaelectronics]

Thanks glad to be here! I look forward to expanding my skillset when it comes to macbooks. As of now the only thing I can fix is shorted caps .

No fault history. I have tried booting in apple diagnostic mode to no avail.

Cpu core voltage is 1.3V from powering on and stays at 1.3v

Caps lock does react

I connected it to a tv. The tv recognizes that something is plugged in but does not display anything.

One more thing to add. Sometimes when I plug it into power it makes the chime that indicates power is plugged in and charging.

 

[2informaticos]

Test external video closing the lid, once machine turns on.
You can also test with internal LCD disconnected.

If you get black screen, move the trackpad left/right and see if the cursor appears.

 

[uintaelectronics]

Tried external video after closing lid with it on. Nothing

Tried with internal lcd disconnected. Nothing

No black screen

 

[2informaticos]

If Caps Lock reacts, board should be booted.
Strange, because CPU core should drop to 0.65V when boots.

Check if its SSD is detected in Target Disk mode.

 

[uintaelectronics]

Tried twice to enter target disc mode by holding T immediately after powering on then connected to a mac studio. Nothing pops up on desktop or in finder. Every time I plug the thunderbolt cable in does chime

 

[2informaticos]

Don't press power button, just press and hold T key.
T2 machines turn on automatically pressing any key, or cliking trackpad.

 

[uintaelectronics]

OK with the macbook not on and connected to the mac studio I press and hold the T key for a few seconds, the fans then spin for about 10-12 seconds and then stops. Nothing shows up on the desktop or in finder

 

[2informaticos]

Check with Disk Utility...

 

[uintaelectronics]

Nothing shows up in disk utility

 

[2informaticos]

Did you still heard the chime when tested in Target Disk mode?

Test if external keyboard works (Caps Lock light).
Just in case, check if is detected in DFU mode.

 

[uintaelectronics]

I did not hear a chime when testing target disk mode. Which makes sense to me because when launching target disk mode the fans stop to spin after 10 seconds so I assume its just turning back off.

External keyboard caps lock light works

Macbook is detected in DFU mode. I tried to revive and then restore. Both times the operation completed successfully ending with the lock icon but during either process nothing appeared on the screen. After restoring i then tried plugging into external monitor with the internal display connected and then disconnected. Still nothing.

 

[2informaticos]

If external Caps Lock works, then you have USB activity.
Can you confirm that on all ports?

You should try again external video, when you have external keyboard working.
Also check CPU core voltage (L7211) in that moment.

BTW, keyboard still reacts after fans stopped?