Apple MacBook Pro 13 inch - Page 44

MacBook Pro (13-inch) Symptom Charts — Startup and Power Issues 44
2010-09-14
5. Reset PRAM. If no action, use
external keyboard with same
sequence. Verify that system
video is displayed.
Yes Invalid or corrupt PRAM
contents aecting video
output.
No Go to step 6.
6. Connect external video:
Connect known-good VGA/
DVI adapter to known-good
display, press power button
and close display to force main
screen startup on external
video. Verify that video is
correct when displayed from
external display.
Yes Video correct on external
display. Research available
rmware and software
updates, retest.
If returning with software
already updated, go to step 7.
No
Replace logic board with
according symptom code:
-no video
-bad/distorted video
M03
M04
7. Isolate LCD display detection:
Disconnect external monitor
and reopen display and restart
unit. Verify that sleep LED
indicator goes o after internal
LCD has been detected.
Yes Sleep LED goes o when LCD
detected.
-If still no video then Go to
step 8,
-If video present, but with
defect, go to step 9.
No Internal LCD not detected.
Run Clamshell Service
Diagnostic utility and check
for LCD panel presence. If
not found, reseat LVDS cable
connection on logic board
and retest. If sleep LED does
not go o after cable is
reseated, go to step 10.
8. Check for sleep sensor
condition. If display assembly
sleep sensor is stuck in a
closed state, video will appear
on internal display temporarily,
until the OS sleeps the system.
Disconnect BIL/ sleep cable
and restart unit without
external display. Verify that
system starts up with video on
internal display stays on and
does not go into sleep mode.
Yes Sleep sensor was stuck or had
shorted cable. Replace BIL/
sleep sensor cable.
X13
No Symptoms unchanged.
Go to step 9.