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Sorry for that.
Resistance BETWEEN pin 17/18 - 3.9 ohms
Resistance BETWEEN pin 27/28 - 21.8 ohms
Yes, board turns on with battery connected, freezes on apple logo. Also reprogrammed BIOS with cleanME, same behaviour.
F7140:
With battery, charger connected - 12.32V
With battery, no charger - 11.67V
Without battery, charger connected - 12.61V
Without battery, no charger - Hovering around 1.5-1.4V.
U7100:
Resistance B/W 17/18 Without charger - 2.8 ohms
Resistance B/W 17/18 with charger - 2.649 Mega ohms...
- MLB was liquid damaged initially with auto shut-down issue
- MLB side KBD backlight connector, PowerGUD section and Thunderbolt section were affected
- Cleaned affected areas and replaced couple of burnt/corroded components
- Ran ASD EFI before completing repair, test passed
- After a month...
- With the battery disconnected, the device turns on with direct power and works perfectly fine.
- Connected the battery while the machine is on. Battery being detected and charging fine.
- Device won't turn on with the battery connected. Same behaviour with known good battery and minimal...
Hi,
The MLB was dead and there was no light on the MagSafe.
- No visible corrosion on the MLB. Found charging IC faulty.
- After replacement, it worked for a while and the charging IC blew again
- Tried with another IC, same.
Please help me with the next steps.
@2informaticos Thanks for the help.
Yes, it was a BIOS issue. After trying 2-3 ICs from the doner board, one worked. Later, I reprogrammed it with the right serial number.
Small issue: The keyboard backlight is not working, could that be because of BIOS?
- working fine at OS level, no ? sign.
Hi,
I did SMC reball and installed another one from doner, same booting slow in Catalina
Also tried a BIOS with clean ME, no go.
In HWMonitor, what values should I look at?
Hi,
Initial readings on Amp meter: 5.085V, 0.026A
- 3 resistors and 1 cap near SSD (U9100) were damaged. Replaced, still, the readings are the same.
- PPBUS_G3H
Diode mode - 0.044
Resistance -25 Ohm
No other visible damage. What shall I do next?
The device was booting but works normally after bootup. Didn't find any abnormal activity in the monitor. Sometimes crashed with a kernel panic.
- On the MLB found corrosion behind CPU (image attached)
- Cleaned up, still behaving same
- Attaching the crash report.
Please help me with the...
- Got this with the backlight not working issue. No liquid/moisture damage.
- After the backlight IC replacement, the backlight started working.
- Now, most of the time the display flickers after restarts for a few minutes.
- Tested with 2 different ICs, same issue.
What could be wrong?
Hi, the device is BIOS locked. I don't have proper tools for reprogramming.
What if I change the BIOS from another same model MLB, will that do?
I am okay with the serial number mismatch.
There was no green/amber light on MagSafe. PPBUS_G3H and PP3V42 present but issue with the SYS_ONEWIRE signal in the SMC.
- SMC area was corroded. Performed SMC reflow and replaced 4 components around it.
- MLB turned on after this but there was liquid damage in various other sections.
- J9500...