(347) 552-2258 [email protected]

820-02098 a2442 no backlight

D

DDVL

Member
Oh this is a fun one. Liquid damaged. Initially didnt power on, thats fixed. Here what i have done so far, anything that looked severly liquid damaged i just replaced.
Here is the list -
Up800
Cp821
Rp801
Rp802
I dont understand this new backlight circut well as i am still learning to understand schematics and the lcd driver page confused me but hopefully with your help i can figure it out.
Alot of the diode mode reading around the chip are normal while comparing with open data and a good donor board.
 
D

DDVL

Member
I see. Well will replace as much as possible then and report back. Also thank you very much for always getting back. Anything in particular i should focus or look at.
 
D

DDVL

Member
Alright so i have replaced everything that had even the slightest bit of liquid that had to do with lcd and saw no broken traces so then i started to look at voltage and see if anything is missing and in that process i have come across luxe c vdd has 0.0 v and when i did diode mode it shows up as 0.06 which tells me its a short but i dont have a donor board with the backlight chip on it. Open board data says 0.500. I don't know if this correct but that would suggest the chip is bad i think but i did take it from a board with working backlight. Luxe_comp is also 0v not sure if that matters.
Thoughts please
 
D

DDVL

Member
So the initial reading of 0.06 was with it on and then when i had taken it off the reading went to 0.07 and started to drop back down. Then i put the cap back on. Also the ohm reading on luxe_c_vdd is 45 with one probe on ground
 
2informaticos

2informaticos

Administrator
Staff member
Then UP800 is bad; no other component connected there.
Just in case, check again with the chip removed; to discard an eventual trace leakage.
 
D

DDVL

Member
Check on cp810 as i have done that and its ol or are you saying to check on the chip directly? Damn that was a chip off a board with working backlight. I wonder what happened. As always really appreciate your help. I will check the chip to be sure but if it is bad it will have to sit awhile as i don't have anymore chips to replace.
God bless you and hope you have a great day.
 
D

DDVL

Member
Took up800 put red probe on pin 7 and black on 32 and diode mode result is 0.06 so chip is now bad but this was a good chip. I wonder if something in the circut shorted it or was it when i reballed it. In any case thank you for the help so far, will revist when i have more chips and will post updates then
 
You must log in or register to reply here.
Top