Search results

Not sure why the change, but after sitting down today to test the board, I currently am missing pp5v_s4rs3... (well I should say it is power cycling). If I am not mistaken, this signal comes from the charging port, so I replaced with a known-good charging board but still same issue. Do not...

Also 0.001V present on PPHV_S0SW_LCDBKLT

Afterlight liquid spill, device powers on with green/orange light, and we get fan spin, but absolutely no image and no backlight visible. Took a few board measurements and tested that all power rails were present, until I noticed 0.001V present on PPVIN_S0SW_LCDBKLT_FET. So far, there is 8.6V...

Fans will not spin without keyboard connector. With only usb-c charger, external adapter to HDMI, and keyboard no external image. With only lcd, charger and keyboard, again no image. Any other thoughts?

Forsure, if the keyboard or trackpad was failing could that prevent an image from displaying?

CPU VCore is 1.08V on pins 1 and 2 of L7211

If it helps i am using 000281 schematic and boardview as closest fit for this model

Have connected external screen and no video image that way. Do not have a dongle that could fit a regular usb mouse. However, the USBs work for charging, but do not get image external on any USB-C ports using HDMI adapter. I have had time to further troubleshoot the board after hand/sonic...

I have an Macbook A1707 that had some liquid spilled on board. I cleaned it off and cannot see too much in terms of obvious damage after the cleaning. When plugged in with either battery, charger, or both, the fans spin but otherwise there are no signs of life. Measuring PPBUS_G3H gives us about...

Got it. The board operation seemed to be digressing as time went on, which is why some of my measurements changed. Now the CPU does not get warm and there is never any fan spin. But thank you for the help, it is a good donor board if nothing else....

It is showing a steady 0V on every test point I could find for PP5V_S4RS3. And U7200 area looks flawless of that is what you are referring to. Does not show any signs of liquid damage. PP5v_s0 and enable are missing as well. Anything else I can do to find what the problem is being caused by?

Yes. 0.3 ohms on L7310. That is unfortunate if that is the case. Does that explain why PP5V_S4RS3 is missing as well(not shorted to GND, just 0V)?

It kind of does take a while. So as mentioned, when the magsage is first connected, there is green/orange light and then after a few moments fan starts spinning for a few seconds then stops. And it will keep going with this loop. CPU initially gets warm, and as the fan goes into this loop is...

Took a look at U7200 and there is 0V on PP5V_S0_CPUVR_VDD pin 16 that jumps to 5.12V when the fan begins spinning. Also noticed that CPU is warm with no fan spin, but when the fan starts spinning the VPU becomes so hot I can barely hold my finger on it. CPU_VR_EN is 0.8V on U7200 that falls to...

Found that there is 0V measured in Diode mode on both pins of L7310 and L7320, however all other inductors seem to measure a normal value.

SMC_PM_G2_En tests at a solid 0.98V with or without the fan spin at pin 1 of RR8140 I rechecked PP5V_S5 and it stays at 4.98V with or without fan spin at pin 1 of C7400 According to customer, the device died one day and she has no longer been able to power it all of the way on, even though she...

I rechecked my measurements and realized that I was missing PP5V_S4RS3 and it was at 0V. Since this rail comes from the dc-in board, I went ahead and replaced that as well but I seem to be having the same issue with this missing power rail as before. After replacing with new DC-in board I took...

With only battery and motherboard, I get 6.83V on PPBYS_G3H that jumps to 7.25V when charger is added. With both battery and charger PPBUS slowly rises from 7.25V to 7.63V and stabilizes. Started going down the power rails, and am posting the measurements I have taken so far: G3Hot is 3.39V...

I get 2.9 ohms between pins 17/18 and 20.5 ohms of resistance between pins 27/28 of U7100. Will test for short on other rails when I get the chance.

I have an 820-00164-A MacBook air that is not powering on and is exhibiting weird behavior on the PPBUS_G3H rail. With charger plugged in and motherboard out of computer I get fluctuating voltages on both pins of F7140. The fan initially begins spinning but dies again after a few seconds...