820-2936 no backlight

[Modder1]

f9700 pin1 12.5 not holding steady.
r9788=12.5
r9782=12.5
r9789=12.2
pin 5 9707=.5
q9706 pin 4=12.5
q9707 pin 3=11.9
q9706 pin 3=12.17
PP3V_SO=3.2
I saw corrosion by pin 6 on 9707 and the pad near it relating to PPBUS_SW_LCDBKLT_PWR
R2055=0.3

my guess is that i replace 9707 based on corrosion. I just don't know how to read properly is what I am thinking.
if anyone can help me where i am going wrong-
thanks in advance

 

[dukefawks]

Well pin 5 on Q9707 should of course be high. Are you sure there is an image? Is SMC_LID high?

 

[Modder1]

for sure image.
SMC_LID @R6961 pin2= 3.44

 

[dukefawks]

Diode mode and resistance to GND on pin 5 of Q9707?

 

[Modder1]

resistance to GND on pin 5 9707 = 99.4
diode mode = 1.0734

 

[dukefawks]

99.4 what Ohm,KOhm, MOhm? Diode mode does not make sense, did you have red on GND?

 

[Modder1]

did not have red on ground, apologies.
0.5512 diode mode
99.4Kohm

 

[dukefawks]

That is as it should be. Do a PRAM reset. Are you sure SMC_LID is high? Are you leaving the battery indicator disconnected?

 

[Modder1]

tried pram reset now without battery indicator connected, no backlight
lcd connector area was also heavily corroded earlier. I have not tried a known working lcd
SMC_LID=3.442

 

[dukefawks]

Is the image still present after the PRAM reset?
Also I hope you are measuring pin 5 of Q9707 with an LCD plugged in, else there will be no voltage of course.

 

[Modder1]

fuck, i was not measuring with lcd plugged in-had no idea there would be no voltage.-will now measure with lcd plugged in and report back
yes there is still image present after pram

 

[Modder1]

3.284 pin 5 9707 with lcd plugged in

 

[dukefawks]

Voltage on C9020 with LCD plugged in?

 

[Modder1]

112, I am not sure it just keeps climbing

 

[dukefawks]

112 volt? Come on, you must know that makes no sense.

 

[Modder1]

I do, let me try again I read it 3 times though.

 

[Modder1]

even with different probes after measuring AAA battery properly it starts around 40 and just keeps climbing I'm sorry man I know you wanna strangle me and I would to if I were you.
I am getting this with everything except battery indicator plugged in if that helps at all

 

[dukefawks]

40 what, Volts, milli volts? Please learn how to use a multimeter first.
Also check R0910 it is common to corrode open.

 

[Modder1]

pin 1 of r0910 is fucked, i cant get solder to stick to it. the pad is gone but i made spot in track for new pad. cant get it to hold to pin 1 though.

 

[dukefawks]

You measure resistance and not voltage when you check a resistor. Please go and learn some multimeter basics before we continue with this.