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Late last night I was able to fix it with blank board serializer. I haven't tried a re-read of the BIOS yet but might when I have time next, just for curiosity. Steve

Hello- I posted similar on ghostlyhaks yesterday but I'm not sure if the site is no longer as active or where people went, so I thought I'd ask here too. I have an A1398 that indicates "Unavailable" as its Serial Number within About this Mac. Everything seems to work fine on the computer...

Hello, I have a 2012 MacBook Air A1466, motherboard 820-3209-A that randomly puts itself to sleep. You can be actively working on something or not touching the computer at all, and the display will turn off and fan spins down. Ran ASD and it put itself to sleep during ASD when running the...

Ok, I'll do the clean ME while I try to find a heatsink. General practice to use a Pomona 5250 on the U6100, desolder, or is there a hirose connector somewhere that I'm missing for this board?

Internal HDD has usually been disconnected and boot from USB sometimes works but when going into OS it still powers off. CPU does get very hot. I took the board out last night and noticed that someone, whether Best Buy or otherwise, apparently tried to redo the thermal paste on the cpu and...

Hello, Working with an 820-2936-B from a 2011 A1278 that we inherited after Best Buy could not fix. The computer has a broken screen but the LCD itself looks fine. It powers on and boot chimes but powers itself down, sometimes partway through boot, sometimes during an Internet recovery. It's...

I too was curious about this, so I went down the rabbit hole for a while. You may have seen this but it's helpful, so I'll put it here for posterity in case anyone else finds this thread; it's specific to this chip and relevant to the overall SMC discussion: [SOLVED]SMC Compatibility Beyond...

I think the issue may have been found, thank you. In looking to measure the pins of J8300, I noticed that L8304 didn't look quite right. Under the microscope, it appears as though L8304 exploded. I cleaned up the surrounding area. C8315 is not looking so good either. I'm attaching a photo...

EDP_BKLT_EN is 0V and BKLT_PLT_RST_L is 3.338V. Looking at the schematic, both of these connect to Q7707 which then must decide whether to enable the backlight or not(?) From what I can tell, EDP_BKLT_EN is created by U0500 or am I reading that wrong?

Hello, Working with an 820-00165 that has green light/orange light, fan spin, and boot chime but no display. Connecting to an external monitor works and the blinking folder shows up on the external monitor. F7700 has 8.57V on both sides but PPVIN_S0_SW_LCDBKLT at pin 1 of L7701 is 0V...

Thank you much for the information on capacitor and resistor substitutions. Do you happen to know if U7750 is ISL6269A or ISL6269B? The datasheet for the "B" version is "with audio clamp" but appears to have the same specifications and pinout. Steve

Yes, I assumed as much on the reference to the voltage for C7771, no worries. Resistance to ground of R7781 is 0.4 ohm which seems quite low. I'm looking for components to remove from old boards but I fear grabbing an already dead cap. I can't seem to find an exact match for the specs of...

I have no problem replacing C7771 but is the problem upstream or before C7771 though? R7751 (pin 2, which corresponds to pin 12 of U7750) is 5.055V. Resistance to ground in ohms is 4.2k. R7780 (P1V05S5_VSNS) is 0.322V. Resistance to ground at R7780 is only 490 ohms. That voltage matches what...

Yes it was low ESR - Panasonic 2TPE330MFB that I ordered from Digikey - arrived earlier today. I used the iron on it also based on what I read in another post here about hot air for that. I've had good success with both Digikey and Mouser but I'm always open to suggestions on other component...

Hello, Working on an 820-2330-A that was easily the dirtiest computer that I've ever worked on. Airflow from one fan was completely blocked. The computer was brought to me as "no power". Magsafe 85W goes green, so one-wire seems ok but no fan spin. After extensive cleaning with no apparent...

Putting closure on this one, it was related to the LIO - though specifically the J7000 connector on the motherboard itself. One of the pins on there must have been broken already which caused inconsistent behavior and maybe was responsible for the initial fuse issue. Once I finished the job of...

Well, J7000, the connector for the charger board may have been the cause of the issues. It broke off the motherboard before I could test this. So now I need to find the connector on mouser or find a donor board that has the same connector for cheap. At the risk of going off-topic in this...

Hello, Seems like 820-00165 day on the forum. I'm working with an 820-00165 board that had a blown F7140. Fixed that but still no power or fan spin and found there to be a short on C7313. Replaced C7313 and now I get fan spin, high speed, but no green light on charger. It also seems like...

No history on it but we were able to flash to a fresh BIOS using a TL866II and it now consistently boots. However, the power button still does not work. The Caps Lock key does not appear to light up when caps lock is on, but the keyboard works fine otherwise. I thought Caps Lock should have a...

Hello, We're working with an 820-2936-B from an early 2011 13" A1278 and the board is behaving inconsistently but never correctly. On boot, the computer will sometimes appear to start correctly, only to kernel panic and reboot before going into a boot loop. Late this afternoon we were able to...