Recent content by HeyWatchOutDude

Any idea?

Hi, I’m working on an A2681 logic board (820-02536) that originally had a 512GB dual-NAND setup. Unfortunately, both original NANDs (UN000 and UN100) are faulty. For testing purposes, I want to convert this board to a single 256GB configuration using a KIC5224 NAND pulled from a donor A2681. I...

I only get 20V when I press hard on the battery connector. I will replace it and try again. Note: Multiple layer damage on that spot, had to remove multiple layers to get rid of the dead short on PPVBAT_AON_CONN

With battery connected I just get an apple logo (without progress bar). It jumps up to 20V. Already tried to get it into DFU, doesnt work. (even with FORCE method)

R8450 = 887kOhm R8451 = 453kOhm PBUS_DIV = 3.6-4V (not stable) PBUS_DIV_SNS = 3.5-3.7V (not stable) PP3V8_AON = 3.5-3.7V (not stable)

Hi, I have a MacBook Air M2 (13” / 820-02536 / A2681) that is stuck at 5V. It had water damage in the following areas: F5200 was blown and has been replaced. R8450 (pin 1 / PPBUS_AON): the pad was missing. After restoring the pad, PPBUS_AON could not be measured there for some reason, so I...

I installed the original NANDs again, and the power cycling stopped. I have no clue why or how. I managed to successfully DFU restore the device, and macOS installed successfully. Any idea what the issue was? There was no corrosion or damage under the NANDs. Edit: As soon I click on a language...

Even with new NANDs same behavior.

Yeah it has another T2 chip, thanks for bringing it up.

So it’s fine? Proposed 16GB Config: MLB_RAMCFG0 = Low (1k ohm resistor to ground) MLB_RAMCFG1 = Low (1k ohm resistor to ground) MLB_RAMCFG2 = High (Pull-up / No resistor to ground) MLB_RAMCFG3 = Low (1k ohm resistor to ground) MLB_RAMCFG4 = Low (1k ohm resistor to ground)

Hi, I have upgraded the RAM on a test machine from 8GB to 16GB (SKhynix 9CCNNNBJTAL). What is the correct MLB_RAMCFG strap setting for this configuration? Proposed 16GB Config: MLB_RAMCFG0 = Low (1k ohm resistor to ground) MLB_RAMCFG1 = Low (1k ohm resistor to ground) MLB_RAMCFG2 = High...

I removed the NANDs, it still power cycles. (but now at 5V / 0.07A) I don’t think the issue is related to the NANDs. Even without NANDs, it should not power cycle.

Theoretically, the power-cycling issue should stop as soon as I remove the NAND chips and power on the device, right? If the same issue occurs, then the NANDs aren’t the problem or am I wrong?

So we can definitely rule out the power rails and sequencing as the main issue before moving on to the NAND task?

Says the same: https://openboarddata.org/?a=showboardsolutions&bpath=laptops/apple/820-02536 And another logicboard (working) has the same readings, so 3V8 can’t be the issue. (I mean 3.8V is also present)