A1278 820-2530-A - backlight repair

holtmann

New member
Hi,

MBP13 (820-2530-A) had burned LCD connector (PIN21/22 backlight burned ) and blown fuse F9800. Replaced LCD connector, LVDS Cable (was also burned on backlight PINs) and F9800. After replacing fuse tested with multimeter and found no shorts in backlight driver and backlight support area. Before attaching screen measured 37-38V on LVDS connector backlight pins. When I attached screen, backlight went on for about 5 seconds and turned off. Measured backlight again for longer on PIN21/PIN22 of LVDS and still got 38V peak, but voltage is not stable and goes down to 6V and then up again. F9800 is not blown and voltage on fuse is 10.7V (should be 12.6V according to schematics). Any ideas what could be broken, should be replaced next?

Thx.
 

dukefawks

Administrator
Are you measuring the 10.7V when on battery power? 12.6V is only present when battery is charged and AC is connected.
 

dukefawks

Administrator
Check again because F9800 should be directly connected to PPBUS. PPBUS without battery connected should be 12.56V.
 
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