(347) 552-2258 help@rossmanngroup.com

820-2936 no image

B

Bohmmen

New member
Hello

I've got this board thats chime ok but there is no backlight or image.

pin 1 u9000 is 0 v

lvds pin 8-18 diode mode

Pin8 0.620
Pin9 0.620
Pin10 0.000
Pin 11 0.620
Pin12 0.620
Pin13 0.000
Pin 14 0.620
Pin15 0.620
Pin 16 0.000
Pin17 0.620
Pin18 0.620

external monitor works.

any suggestions?

is it u1800 that is bad or is it something with lid?
 
A

aprendiz

Moderator
Have you tried another display assembly?? It is water damage?? if yes inspect LVDS connector if it is evident water damage replace connector first...
 
D

dukefawks

Administrator
The important pins here are 4 6 and 7. 4 should have 3V and 6 and 7 should check the same on diode measurement. Also make sure SMC_LID is high.
 
D

dukefawks

Administrator
Looks ok. Now try with a separate LCD cable and see if pins 4, 6 and 7 make it to the other side. I suspect a bad pin 4 in the connector so no 3V to the EEPROM in the LCD.
Did you do a PRAM reset just to be sure?
Do you have another LCD assembly to test? 2008-2011 models should all work.
 
B

Bohmmen

New member
I have multiple lcd assemblies but it makes no differense. Tried a separate cable, it was hard to meassure but everyting was ok.

Don't you think it has anything to do with U9000 as I have 0v on pin 1, ON. LCD_IG_PWR_EN . I have 0 volt on U9000 output
 
B

Bohmmen

New member
diode lvds unconnected

pin 4 0.349
pin 6 0.614
pin 7 0.613

connected is same.

didn't diode check pin 4 erlier. is it reading to low?
 
D

dukefawks

Administrator
Pin 4 is fine as long as there is 3V and it will not drop with LCD connected. Pin 4 and 6 should drop if you plug in an LCD. Try other LCD assemblies to see if there is any difference. Try again with just a cable and see if pin4 and 6 come out the other end
 
B

Bohmmen

New member
Good Morning.

pin 4,6,7 is all 3.3 volt at the loose end with just a cable. Same measurements at connector both with and without lcd connected. when lid is closed i get 0.063v at 4,6,7
 
D

dukefawks

Administrator
Lid open or closed should not matter on pin 4 as it is connected to 3V_S0. Check again to be sure. Did you do a PRAM reset?
 
B

Bohmmen

New member
I attatch magsafe, lid closed, fan start spinning, DOONG, 3.3v at pin 4, after a while fan stops, 0,063v at pin 4.
Yes, I did PRAM reset. Tried 5 different LCD that works with other boards.
 
D

dukefawks

Administrator
Are you getting any voltage on C9020? LCD attached lid open of course. I'm running out of ideas on this one.....
Also what caused the original damage around the ISL6259? Must have been liquid.
 
D

dukefawks

Administrator
The LCD is definitely not recognized then. I have no idea why, but only thing I can say now is change the LCD connector...
 
You must log in or register to reply here.
Top