820-2850 Yellowish Whites

[RyanLEN]

Tried known working display assemblies. Is this GPU or ??? Thank you.

https://photos.app.goo.gl/Ou7kBYFEadwOaW3v1

 

[aprendiz]

First, measure data lines from J9000 in diode mode and report values, other than that, seems to be a GPU failure, have to say that ive not seen this failure that much like on 2915 boards but could be GPU...

Also you can test by appying heat to the core of GPU..

 

[dukefawks]

Bad LCD connector or a MUX issue. Measure all LVDS lines at the LCD connector on diode mode.

 

[RyanLEN]

pn6 .478
pn7 .478
pn8 .593
pn9 .593
pn10 0
pn11 .593
pn12 .593
pn13 0
pn14 .593
pn15 .593
pn16 0
pn17 .593
pn18 .593
pn19 0
pn20 .593
pn21 .593
pn22 0
pn23 .593
pn24 .593
pn25 0
pn26 .593
pn27 .593
pn28 0
pn29 .593
pn30 .593


Thanks

 

[larossmann]

Tap U9600.

 

[dukefawks]

Yeah push on U9600 and see if image changes.

 

[RyanLEN]

no change when pushing/tapping on U9600.

 

[Gurmon]

Have you tried heating GPU as per aprendiz suggestion ?

 

[RyanLEN]

I haven't. Reason is, I have swapped three different LCD's in the total time working with this board. All known working. One of the three is a "matte" finish LCD which seems to be working fine with it. All colors are normal. I have retested the other two "glossy" with different working boards to be sure they are working, and they are. Confused. Thanks for your reply.

 

[dukefawks]

My main suspects here would be LCD connector, L9010/11, Termination resistors R9320 and up. Check 1V8 and 1V2 power to U9600 I have seen 1V2 line be low. Last thing would be MUX or GPU.