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Hi! Having changed U8900 and it?s related RC components, replaces Q8930 I have PPVCore as 1.05 which drops to 0.89 on fan spin (GPU has been removed to troubleshoot for now). HOWEVER , GPU FB Supply and GPU 1V05 Supply remain 0V on fanspin with GPU removed. My question is, are the supply...

GPU and Q8930 replaced. Coil resistance drops to 5.6 Ohms. System boots. No excessive heating of any component but still no vcore GPU and hence no eDP image. please advise on further diagnosis.

Will replace GPU and update asap.

R/C Components check OK around the 62882 and Q8930. Request you to point me to the specific test points. Further, PPVCore_GPU is 0.97V when Q8930 heats up. Is there a possibility of the GPU (despite showing 16-18 ohms at coil) being somehow internally shorting leading to a virtual overdrive...

As stated, fans spinned, system chimed with Q8930 removed. However, Replacing Q8930 as well as 62882 and powering the board with MagSafe results in F7040/41 voltage dropping to 3.2V (resultantly no fan spin/ chime anymore) with coil showing a PPVCORE_GPU voltage of 0.97 and Q8930 heating...

Thanks much.

Is there a way to check if the Q8931/61 are good by on-board diode mode voltage or normal resistance checks? kindly advise on this as finding replacement equivalents introduces another variable in the equation of an already complicated scenario of GPU/Q8930/62882

Please advise if I also need to replace Q8961/31 649135PBF along with the Q8930. If so, as the 649135PBF is getting hard to find, a reference source will be highly appreciated.

L8930 to ground does show 18 ohms!

Alas it was powered up before I posted when the Q8930 was shorted.... 18Ohm was Fuse F7040/41 to ground PRIOR to removal of the Q8930. Have ordered the Q8930 at Mauser so will take a few days. At the moment after removing Q8930 and replacing the 62882 I did power up with GPU and CPU both...

Removed Q8930. Fan spin and system chimes - though the original issue of eDP remains to give a background, I had to remove the U8900 as pin 39 was perhaps shorted to pin 40 though the embedded LCD worked. After replacing U8900 the display disappeared. I again removed it. then suddenly the issue...

Aaaah! My Bad. Though I just checked, removing Fuse 7040 and 7041 shows 12.5V on pins 1 of the fuses. meaning something after the fuses is pulling PPBUS_G3H town to 2.5V. Hope this didn't fry the Q8930!

Hi: Im having an issue with a A820-3332 motherboard with PPBUS_G3H at 2.8V instead of 12.6V No chime, no fan spin one wire-circuit working with green light on MagSafe. On scouting, I find this may be perhaps because of PPV removing U8900 (62882), the PPVCORE_GPU shows 18 ohms to ground! Please...

Hi! Yes, the supply does come after 5 seconds for a couple and then disappears. On investigating further I found the case of a bad pad under L9004 leading to the system not registering the EDP. Replacing the Inductor and making good the connection restored the EDP display as well as backlight...

Tried with known good panel and rechecked the connection pins. No 3V3_SW_LCD still...

Sorry, I meant resolder and not reflow. Nevertheless, both signals show short to ground though eDP retina panel works fine. just want to check if the signal levels in off state are correct.

Hi: Im reflowing the famed U8900 in an A1398 2012 MBP Retina 15 for display issues and notice that the continuity on PIN 39 and 40 in system off state (power and battery disconnected) is short to ground. Can someone please confirm if the PIN 39 with signal GFXIMVP_DPSLP_EN and PIN 40 with...

Hi: I will appreciate any help in diagnosing missing PP3V3_SW_LCD_UF from U9000 due to which the system is unable to detect embedded LCD panel. On checking I find that LCD_IG_PWR_EN (input to U9000) is also low. System boots and external display port is working. Please Guide...

Removed R9810 to restore BKLT_EN and Replaced R1600 with 200K to maintain 3.2V. Subsequently, 1. System booted with SSD 2. Both USB ports worked 3. Backlight sustains at full brightness and PPVOUT_SW_LCDBKLT measures 24V As you rightly say, it seems to be a busted driver inside each of the two...

Sorry, it?s 9810. Pull down for LCD_BKLT_EN before pin 5 of Q9807.