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Текущая версия: Charles ,

Текст:

I’ve had the same problem on a 2009 27” Quad Core i7 iMac.
 
# The display comes on but the backlight will not stay illuminated unless set to a lower setting (+3 on the scale).
# I have found that when the light nears going off, the 3.3 volts coming from the Logic Board to the backlight inverter board has sagged to 2.9 volts and suddenly drops to 2.7 volts when the backlight goes off.
# When the backlight has failed, I can use keyboard commands to make it sleep and then reawaken, but the backlight will not stay illuminated unless set to the lower illumination setting of +3 or less.
# I have found that if the computer is unplugged overnight, the display will run at full illumination for about four hours before the faulty behavior begins to occur again.
# I have read elsewhere that the 3.3 volt signal to the backlight board is what commands power to the backlight or turns it off. This voltage is supposedly generated by the Video Card.
# Others have claimed they have severed this connections and provided an alternate 3.3 volt signal to the inverter board so it always stays on. This will be my next step to see if the problem can be remedied.
Has anyone had any experience inwith regard ofto the 3.3 voltvolts going to the inverter board?
Has anyone had any experience inwith regard ofto the 3.3 voltvolts going to the inverter board?

Статус:

open

Отредактировано: Charles ,

Текст:

I’ve had the same problem on a 2009 27” Quad Core i7 iMac.
 
# The display comes on but the backlight will not stay illuminated unless set to a lower setting (+3 on the scale).
# I have found that when the light nears going off, the 3.3 volts coming from the Logic Board to the backlight inverter board has sagged to 2.9 volts and suddenly drops to 2.7 volts when the backlight goes off.
# When the backlight has failed, I can use keyboard commands to make it sleep and then reawaken, but the backlight will not stay illuminated unless set to the lower illumination setting of +3 or less.
# I have found that if the computer is unplugged overnight, the display will run at full illumination for about four hours before the faulty behavior begins to occur again.
# I have read elsewhere that the 3.3 volt signal to the backlight board is what commands power to the backlight or turns it off. This voltage is supposedly generated by the Video Card.
# Others have claimed they have severed this connections and provided an alternatedalternate 3.3 volt signal to the inverter board so it always stays on. This will be my next step to see if the problem can be remedied.
# Others have claimed they have severed this connections and provided an alternatedalternate 3.3 volt signal to the inverter board so it always stays on. This will be my next step to see if the problem can be remedied.
Has anyone had any experience in regard of the 3.3 volt to the inverter board?

Статус:

open

Отредактировано: Charles ,

Текст:

I’ve had the same problem on a 2009 27” Quad Core i7 iMac.
 
# The display comes on but the backlight will not stay illuminated unless set to a lower setting (+3 on the scale).
# II have found that when the light nears going off, the 3.3 volts coming from the Logic Board to the backlight inverter board has sagged to 2.9 volts and suddenly drops to 2.7 volts when the backlight goes off.
# II have found that when the light nears going off, the 3.3 volts coming from the Logic Board to the backlight inverter board has sagged to 2.9 volts and suddenly drops to 2.7 volts when the backlight goes off.
# When the backlight has failed, I can use keyboard commands to make it sleep and then reawaken, but the backlight will not stay illuminated unless set to the lower illumination setting of +3 or less.
# I have found that if the computer is unplugged overnight, the display will run at full illumination for about four hours before the faulty behavior begins to occur again.
# I have read elsewhere that the 3.3 volt signal to the backlight board is what commands power to the backlight or turns it off. This voltage is supposedly generated by the Video Card.
# Others have claimed they have severed this connections and provided an alternated 3.3 volt signal to the inverter board so it always stays on. This will be my next step to see if the problem can be remedied.
Has anyone had any experience in regard of the 3.3 volt to the inverter board?

Статус:

open

Отредактировано: Charles ,

Текст:

I’ve had the same problem on a 2009 27” Quad Core i7 iMac.
 
# TheThe display comes on but the backlight will not stay illuminated unless set to a lower setting (+3 on the scale).

# . I

# I
have found that when the light nears going off, the 3.3 volts coming from the Logic Board to the backlight inverter board has sagged to 2.9 volts and suddenly drops to 2.7 volts when the backlight goes off.

# When

# When
the backlight has failed, I can use keyboard commands to make it sleep and then reawaken, but the backlight will not stay illuminated unless set to the lower illumination setting of +3 or less.

# I

# I
have found that if the computer is unplugged overnight, the display will run at full illumination for about four hours before the faulty behavior begins to occur again.
# TheThe display comes on but the backlight will not stay illuminated unless set to a lower setting (+3 on the scale).

# . I

# I
have found that when the light nears going off, the 3.3 volts coming from the Logic Board to the backlight inverter board has sagged to 2.9 volts and suddenly drops to 2.7 volts when the backlight goes off.

# When

# When
the backlight has failed, I can use keyboard commands to make it sleep and then reawaken, but the backlight will not stay illuminated unless set to the lower illumination setting of +3 or less.

# I

# I
have found that if the computer is unplugged overnight, the display will run at full illumination for about four hours before the faulty behavior begins to occur again.
# I have read elsewhere that the 3.3 volt signal to the backlight board is what commands power to the backlight or turns it off. This voltage is supposedly generated by the Video Card.
# Others have claimed they have severed this connections and provided an alternated 3.3 volt signal to the inverter board so it always stays on. This will be my next step to see if the problem can be remedied.
# HasHas anyone had any experience in regard of the 3.3 volt to the inverter board?
# HasHas anyone had any experience in regard of the 3.3 volt to the inverter board?

Статус:

open

Оригинальный сообщение: Charles ,

Текст:

I’ve had the same problem on a 2009 27” Quad Core i7 iMac.

#  The display comes on but the backlight will not stay illuminated unless set to a lower setting (+3 on the scale).

# . I have found that when the light nears going off, the 3.3 volts coming from the Logic Board to the backlight inverter board has sagged to 2.9 volts and suddenly drops to 2.7 volts when the backlight goes off.

#  When the backlight has failed, I can use keyboard commands to make it sleep and then reawaken, but the backlight will not stay illuminated unless set to the lower illumination setting of +3 or less.

#  I have found that if the computer is unplugged overnight, the display will run at full illumination for about four hours before the faulty behavior begins to occur again.

# I have read elsewhere that the 3.3 volt signal to the backlight board is what commands power to the backlight or turns it off.  This voltage is supposedly generated by the Video Card.
# Others have claimed they have severed this connections and provided an alternated 3.3 volt signal to the inverter board so it always stays on.  This will be my next step to see if the problem can be remedied.
# Has anyone had any experience in regard of the 3.3 volt to the inverter board?

Статус:

open