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It turned out that the caps on the other side were shorting. PPBUS_AON is stable now. However, that middle amplifier had corroded pads and had to remove it. together with a bunch of filtering caps around it. It seems to be the same amplifier as -02100 SN012776B0YBH Without it, it turns on now...

Using the magsafe charger stuck at 5V PPBUS_AON - 0.169V with fuses on; 12.93V with removed fuses. Seems like U5200 is fine. Shall I lift up all coils and determine where it is reaching? Particularly audio amplifiers look bad , but no direct short

Thanks for the explanation. Much appreciated. I use this portable buck converted with CV/CC protection, and I usually set/limit it to 2.5A with 2V when injecting, and if nothing heats up, then I start ramping up the current (if CC triggers) or voltage(if line permits). This time it was not...

I am aware of the Ohm law, but I haven't thought of how it will apply in this scenario. What first-hand materials would you suggest for basic electronics knowledge? My 50Ohm on the PPBUS_AON fuses now measures 150Ohm. PPBUS_AON - 0.152 (both ways in diode mode), still lower than TCSR reported...

Fuse Side - 50Ohm. I cannot find the same or lower value on any coils. The closest I get is 120Ohms. I usually use this little buck converter with a Lithium battery limited to 2V and 2.5A. I also tried with the 1V and 2V 15A linear bench supply. But not pulling any current. Strange. -...

Bit shooting in the dark here without schematic and boardview. I can detect shorts in the PPBUS_AON fuses. I pushed 2V through the shorted PPBUS_AON line but did not pull any current. Perhaps too low voltage to trigger any short. Anything to consider before I ramp up the injected voltage to...

Apparently, it is a common area for these to get watered and melt that connector. There is bt more info here - https://www.badcaps.net/forum/showthread.php?t=108433&highlight=A2442

Had this before with a 2013 A1398 model as described by TCRS - . Resoldering pads resolved the problem in that case. Thought this could be the same as it wasn't showing internal video, but external seemed to be working. Agree. I should not have touched U7400. The low resistance on its pins...

Hi Guys, Have this board that has a black internal screen but used to work on the external screen. A graphic load software won't start on the external screen. Thought it could be a U8900 cold joint issue and resoldered it, in the process resoldered U7400 as well. Afterwards, the board won't...

Thanks, suspecting the SMC reset after fixing that traces didn't go well. Tested with third battery and start charging. When I placed the original battery now, it is pulling >1A current, but seems like internally is not functioning well as it shuts down the minute I pull the plug. Works with...

Got this A1466 with shorted PPBUS_S5_HS_COMPUTING_ISNS C7313 Tantalum Cap and F7140 Fuse. Now turns on and works on Battery. It Shows Battery Charging but pulls under 0.6A and does not charge the battery. After draining the battery, is now not charging it anymore. Tested another charged...

Ah, this seems to be the problem. Thanks 2informaticos

I got this Macbook not turning on with slight oxidation around C3898/99 on the PP15V_TBT line. I cleaned and replaced the caps, and now I am getting 15V on the PP15V_TBT line. It worked fine for a week, then shut down and would not turn on anymore. After reconnecting, the battery now turns on...

Replaced U3220, no corrosion around/at J3200. UC must have cleaned it. With Replaced U3220 I have lost video on external completely (Only Black Screen). Returned the chip back, but still no video. Perhaps heating in the area must have separated corroded U2800 balls. Reflowed U2800 by removing...

Diode OK - Same reading as donor When Ground on 2/R3081 P1/D3095 - 8.5V P2/D3095 - 14.5V Same greenish Display When the ground is removed, Diode readings fall to 0V

No Change

I thought the same, but wasn't sure about reflowing it. Especially inside of that shield frame. No Short to ground on D3095

yes DP_TBTPA_HPD - 3.2V

I come across another issue on this one. Everything works fine but there is no external display via the Display Port when the internal LCD is connected. When LCD is disconnected there is a greenish fuzzy picture, TBT_A_HPD - Goes 3.3V when TB connected TBT_A_HV_EN - missing with connected or...

Well had liquid damage. And I don't have a spare one to test. But with a disconnected screen and turning on the machine I would have thought I will get something on the USBc HDMI output Unless I get a spare LCD to test seems like I'm at a dead-end