820-3302-A imac no display

[Yoel Ren]

lcd cable is broken, c9715 is broken in half, i removed it, but there's a short but not full short, about 20 ohm.
I then proceed to remove c9709, c9799, c9795 and c9717. But there's a short ? about 50 ohm, does that mean there's still leakage ?
i cannot inject voltage like this, is my best bet to remove all caps ? there's a small crater at c9795pin 1

 

[2informaticos]

Polish the "crater" edge.
You probably have leakage between copper layers.

 

[Yoel Ren]

i have found the short beneath some layer, now bklt_boost resistance is around 1.7k ohm, i use caps thats the same size for the caps i removed before, is that okay ? or should i use same specification? diode mode 0.293
if i pwoer it on without screen, its normal, but when i power it on with screen, i smell some burn but idoesnt found anything blown..
l9100 is 0.5 ohm resistance, is that okay ?

 

[Yoel Ren]

r9708 is shorted. is there any part from macbook donor i can use ? i can't seem to find any..

 

[2informaticos]

"r9708 is shorted"
I have never heard about shorted resistor!!!
What do you expect from a 50 miliohm resistor???

Did you check resistance to ground at backlight output with LCD connected?
If no short, the smell denotes the backlight voltage try to go high and leakage still present between copper layers.

 

[Yoel Ren]

but that resistor is connected to ground, and the resistance is 0.1 ohm.. correct me if im wrong
iassume pp12v_lcd is the output ? resistance to ground is about 2k ohm with screen connected.
any replacement for this r9708 ? cause its blown..

 

[Yoel Ren]

when i see 0.1 ohm resistance to ground on r9708, i then inject voltage there which blown r9708

 

[2informaticos]

I cannot beleave that!!!
Good luck to find replacement resistor now.

I cannot help if do not even read me...

 

[Yoel Ren]

im sorry.. i read every your message carefully.. english is not my native language so ims orry if i miss something.
yes i read that resistor is 50mili ohm, but there's no resistor package with that size from donor board, is it okay if i use smaller resistor with jumper wire ?

 

[Yoel Ren]

wait.. even jumper wire is at least 0.1 ohm in resistance..

 

[2informaticos]

You had 0.05 ohm (50 miliohm) resistance.
What reading did you expect to get, apart of pure short???

 

[Yoel Ren]

i have replaced the r9708
I have pp12v going
I can seeimage by flashing the lcd, so its no backlight problem to be exact..
L9100 is fine
f9700 is fine
I have tried replacing q9700 too
diode mode d9700 with another board, similar result.. any idea ?

 

[Yoel Ren]

I have another board so I already eliminate lcd and display cable problem

 

[2informaticos]

If you have working board, then compare diode mode readings between boards, in the backlight area.