Recent content by stef4n

Hello I started working on a 820-2915-B. When charger was plugged, I had a green light, but no fan spinning and no boot. C7200 was missing on the logic board. Found the feet of the cap in place but the cap's body was gone. Plus, C7203 seemed partially damaged. I replaced them, and plugged the...

Hello, I got this A2141MBP a few month ago. It wasnt able to boot nor display anything. I let it on a shelf. I plugged my USB-C ampmeter today on each USB-C port. Being in front of the MBP, I got: USB-C, left* side, back*, 20V and 2.4A. When I pressed on On, or maybe before, I got the "empty...

Do these models work the same way as the 13" A1502, whose defective trackpad cable cause both the trackpad and the keyboard to not function ? It happens so often on A1502, but that would be a first on a A1398. Got 13.60V on PPVIN_S4_TPAD_FUSE (trackpad cable lifted -> fans full speed) PP3V3_S4...

I have a A1398 820-00138-A able to boot after I press on ON. The OS loads, and I reach the login screen. There, the trackpad does not click, the cursor does not move. It behaves as if the macbook was turned off. Not a single key of the keyboard works. The keyboard does have its backlight. If I...

"That way is rarely used for diode mode readings." What is the correct way ? C7630 replaced, other cap and traces were OK Fixed ! MacBook Air alive :) Thanks 2informaticos for the direction

Good evening 2informaticos, 0.078V on pin 1 of C7278, 0.078V on pin 1 of R7280 0.078V on pin 1 of R7279 0.078V on pin 1 of R1931 (Black probe on ground) And indeed, it looks like I should have had 1.05V there according to...

Hello, I have a MacBook Air that suddenly stopped working while I was reinstalling the OS. No prior work on the logic board. PPBUS_G3H: 8.58V PPBUS_S5_HS_COMPUTING_INS: 8.58V PPBUS_S5_HS_OTHER_ISNS: 8.58V PPDCIN_G3H: 16.42V PP5V_S0: 5.08V PP3V3_S0: 3.304V PP3V3_S5: 3.304V (as I have S0...

The battery of my multimeter was dead...I have the correct voltage on pins 2, 5, and 13 of U1900. Nice and steady 3.3V, 3.42V. Visually all the caps look good. How do you proceed in such a case ? Take each cap out of the board and test them ? Or replace all of them ? There is no sign of...

pin 4: 314mV Other pins values are disturbing. I checked after having resoldered, I had the PP3V3_S5 yesterday. I plugged the powercable a few min ago but this morning I have nothing. pin2 & pin5 "peak" for a fraction of a second at 3.x V when I touch the pin with the multimeter probes prior to...

All caps looked good. I replaced U1900 with a chip from a donor board. I have 1.26V for PPVRTC_G3H. Still far from 3.3V SYSCLK_CLK32K_RTC now shows 35mV (233mV before) PCH_DSWVRMEN : 1.217V PM_DSW_PWRGD: 2.094 V I blew C1740 a few times. I put it back in place. Is there a polarity on this...

Thanks 2informaticos; I will check C1924, C1920, C1922, C1902, C1905, C1906, C1910, C1102, C1103 tomorrow evening and update this reply once done. Will see if I can find a donor board by then, for U1900 replacement. Otherwise, I will order a bunch of U1900. In all cases I will update this post...

Good Evening 2informaticos, SYSCLK_CLK32K_RTC : 233mV PCH_SRTCRST_L : 1.21V PCH_INTRUDER_L (R1101, pin2) : 1.104V PCH_INTVRMEN_L (test probe & R1100, pin2) : 1.174V RTC_RESET_L : 1.21V (PPVOUT_S0_PCH_DCPRTC : 2.4mV) (PPVRTC_G3H : 1.215V) Regarding the other measures, as per yesterday for 3 of...

Good evening, I started investigations on a board that suddenly stopped working out of the blue. I get an Amber Light, fan spinning, PP5V_S5, PP3V_S5, but no S4. I do not have any PP3V3_SUS. Logic board is out of the case. PPBUS_G3H: 12.53V PP5V_S5: 5.00V PP5V_S4: 0V PPVRTC_G3H: 3.24V...

Hi, I'm on a 820-3462 board that does not chime. There is no image on screen, and no light if USB Mouse plugged. Fans are spinning. The board is able to charge the battery, and remains powered on if i unplug the charger or the battery. This part of the circuitry seems working. I get the orange...

Hello, I got a MacBook Air 2020 M1 13i A2337, logic board 820-02016, able to boot, and works properly if I plug an external monitor and close the lid. However, there is no way to see anything on the macbook air's screen itself; it stays black. I measured CP860, pin 1, it goes up to 357mV...