Beeldbuisje
New member
Hi, very first post on this nice forum. Read a lot here, but I've never seen something equal to my mystery. Hopefully it has a solution...
So, after connecting charger, Apple logo after a while, no progress line. After 5 secs reboot and so on.
Switching to VERBOSE mode gives more info (see picture), but always ends up with EB|LOG:EXITBS:START. Reboots and always the same.
Macbook reboots when PM_SYSRST_L becomes low for a second.
Trying to enter recovery gives backlight, but no more text, nor Apple logo
Connect USB with OS, press option and switch on, gives USB activity, but again only backlight, nothing else. Just like with recovery, the whole thing reboots after a while.
Measured every tension, everything is present.
PPVCC_S0_CPU is 0,6V when Apple logo is displayed, just after reboot it's 1,1V.
Maybe some useful history of this board...
The owner dropped the Macbook from a table. After that, nothing, but CPU became very hot. When this thing became very hot, blowers goes blowing. After some "jumping", board w/h battery pulled 666mA steady.
Reballed CPU, same behavior.
Reflowed SMC which gave backlight at the first try, but while booting Suddenly just 20mA steady on my USB-C meter. C1061 on PP1V2_S3_CPUDDR became shorted (coincidence?). Replaced and I've got backlight again and the Apple logo which always reboots.
SMC bypass mode doesn't work I think (blowers don't start to blow at full speed).
When I disconnect touchpad, reboots are faster. Such fast that I've nothing more on the screen. In that case gives an SMC reset (reset pins on the board) an Apple logo once, until the first reboot.
At last attempt, I've reballed SMC, the same behavior.
Spent already days on this...
Thanks for the info!
Gert
So, after connecting charger, Apple logo after a while, no progress line. After 5 secs reboot and so on.
Switching to VERBOSE mode gives more info (see picture), but always ends up with EB|LOG:EXITBS:START. Reboots and always the same.
Macbook reboots when PM_SYSRST_L becomes low for a second.
Trying to enter recovery gives backlight, but no more text, nor Apple logo
Connect USB with OS, press option and switch on, gives USB activity, but again only backlight, nothing else. Just like with recovery, the whole thing reboots after a while.
Measured every tension, everything is present.
PPVCC_S0_CPU is 0,6V when Apple logo is displayed, just after reboot it's 1,1V.
Maybe some useful history of this board...
The owner dropped the Macbook from a table. After that, nothing, but CPU became very hot. When this thing became very hot, blowers goes blowing. After some "jumping", board w/h battery pulled 666mA steady.
Reballed CPU, same behavior.
Reflowed SMC which gave backlight at the first try, but while booting Suddenly just 20mA steady on my USB-C meter. C1061 on PP1V2_S3_CPUDDR became shorted (coincidence?). Replaced and I've got backlight again and the Apple logo which always reboots.
SMC bypass mode doesn't work I think (blowers don't start to blow at full speed).
When I disconnect touchpad, reboots are faster. Such fast that I've nothing more on the screen. In that case gives an SMC reset (reset pins on the board) an Apple logo once, until the first reboot.
At last attempt, I've reballed SMC, the same behavior.
Spent already days on this...
Thanks for the info!
Gert