MacBook Pro 15" A1398 black screen after battery replacement
crwdns2934249:0crwdne2934249:0:
Hi everyone, a friend asked for help with his MacBook that was stuck in a boot loop, displaying only the Apple logo and a loading bar. After trying SMC and NVRAM resets, I reached the user menu, but the loop resumed after entering the password.
I noticed a bloated battery before opening the device, and inside, I found a very defective battery. Disconnecting it didn't stop the loop. I found a video suggesting disconnecting the display and trackpad, which worked—albeit slowly—using external peripherals.
Research indicated the boot loop could be due to the battery design. I ordered a new battery, backed up the data using the same workaround, and cleaned the dusty internals. With the new battery installed, I only heard the fans without any display. An SMC and NVRAM reset brought back the boot chime, but still no image.
Shining a light revealed an image without a backlight. External monitors worked fine, suggesting a backlight fuse issue. Despite checking continuity with a multimeter and cleaning connections, the issue persists.
Any ideas on what might be causing this? I've handled similar Apple device repairs but never encountered this problem before.
MacBook Pro 15" A1398 black screen after battery replacement
crwdns2934249:0crwdne2934249:0:
Hi everyone, a friend asked for help with his MacBook that was stuck in a boot loop, displaying only the Apple logo and a loading bar. After trying SMC and NVRAM resets, I reached the user menu, but the loop resumed after entering the password.
I noticed a bloated battery before opening the device, and inside, I found a very defective battery. Disconnecting it didn't stop the loop. I found a video suggesting disconnecting the display and trackpad, which worked—albeit slowly—using external peripherals.
Research indicated the boot loop could be due to the battery design. I ordered a new battery, backed up the data using the same workaround, and cleaned the dusty internals. With the new battery installed, I only heard the fans without any display. An SMC and NVRAM reset brought back the boot chime, but still no image.
Shining a light revealed an image without a backlight. External monitors worked fine, suggesting a backlight fuse issue. Despite checking continuity with a multimeter and cleaning connections, the issue persists.
Any ideas on what might be causing this? I've handled similar Apple device repairs but never encountered this problem before.