820-3115 No Display and Missing LCD_IG_PWR_EN = LVDS_IG_PANEL_PWR on U9000

[rany]

HISTORY: board previously worked on, fucked-up connector, shorted back-light circuit, PPVOUT_SW_LCDBKLT also shorted to ground.

PROBLEM: no display, but have display on external screen.
Cleared short on backlight, got backlight but no display. Replaced connector, lost back-light, going to trouble shoot it again tomorrow.
AND the connector has same # of pins but different anchors, worked before. Is it a problem?

U9000 was nicked, I replaced it. Then tested and found 3.33V on PINS 2,3; 0V on PIN 1 = LCD_IG_PWR_EN = LVDS_IG_PANEL_PWR = L_VDD_EN (out) from U1800; 0V on remaining PINS of U9000.

First (dumb question): display must be connected to get this voltage, like for backlight? I tried two displays, but not sure I have a known good anymore and getting new one tomorrow. Asking to buy time till I get the new display.

Two, PP3V3_S5 is 360 OHM to ground, and donor board is giving me more than 2K. Is this a problem or part of my problem?

Three, U1800 needs an input somewhere to output L_VDD_EN?

Four: any usual suspects when we have no display on this model?

ALSO, I tried searching for previous posts, but got 0 results. Is the search engine down?

TIA!

 

[dukefawks]

Yes LCD must be connected for any of this to work. Check for 3V on C9010 and check if LCD connector is properly soldered, need data connection on pins 6/7 for LCD recognition.
You are using the 2012 connector and not 2011 and older?

 

[rany]

You are using the 2012 connector and not 2011 and older?

Older is what I have on hand. It is properly soldered. Otherwise I can harvest a 2012 connector. New ones need 1 more week.

Will measure everything else tomorrow with known good display and report back.

 

[dukefawks]

Get the proper parts, no use trying to fix this half assed.