Search results

resistance over c5220 is in the millions Diode mode to ground on U8100/U7700 found no shorts. usbc port with UF400 cycles on and off every few seconds. No shorts and both 1.5v and 3.3v LDO's are present

LID_OPEN_LEFT/RIGHT and IPD_LID_OPEN are all present 1.8v A new observation is when the board alone is on the desk the left ports boot to 20v but the right is only 5v 0.25amps. Tried reflashing UB260 but no change All LDOs are present on U3100W/U3100R

3V8_AON 3.8V All U8100 LDO's loop every few seconds

PPBUS 0.490 3V8_aon 0.380 3v8_AON_ATC_ISNS .340 3V8_AON_DFR_ISNS .340 3V8_AON_MPMU_ISNS_VIN .340 3V8_AON_SPMU_ISNS_VIN .340 C250 12.30V with F5200 removed P_IN 5V AUX_DET 2.1V CHGR_RST_IN 0V VDDA 5.15V VDDP 5V EN_MVR 5V AUX_OK 1.77V AMON 0.36V BMON 0V

No liquid damage. Both ports are 5v 0.18a drops to 0.02amps then loops over. At times unplugging and plugging back in 20v will appear for a few seconds. PPBUS_G3H starts at 12.30v then 12V before looping. Only getting 5v at PPDCIN_AON_CHGR so replaced U5200 after checking...

Arrived with U3200 burned along with blown r200/203. After replacing and changing U3200 from a donar board no change, only 5v. Noticed short present on PP5V_G3S. U7210 was shorted. PP5V_G3S short gone after replacing but still only 5V on charger. PPBUS_G3H is 12.33V. Using 96 watt original...

This arrived with very little liquid damage. After removing C6501-C6503 and C6405 board started to boot with 20v for a few seconds but boot looped and then was stuck at 5v. Reviving T2 in DFU solved the 5v issue. The machine now turns on and boots into the OS. The issue is when you go to...

No change after DFU restore. What do you suggest should be checked next?

Once I am in DFU whats the next step? I have never cleaned ME regions manually before, only used the Medusa programmer to do it. Does a dfu restore need to be performed to clean the ME region?

How do you perform that procedure? I assume you can’t use medusa on this one

Is it really possible for PCH and the GPU to just randomly die ?

When testing external I plug in through usb-c port and turn the imac on. Do any special keys need to be pressed on the keyboard during testing?

No external video with and without internal lcd connected. Caps lock light comes on No change after DFU revive

PCH replaced successfully. Board turns on chimes and boots now however no image or backlight on the screen. The first three lights come on but light 4 and 5 remain off. Do you need to perform a DFU revive after PCH replacement??

Before measuring rails a DFU revive was also performed and completed successfully even though nothing ever appeared on the screen. Should something else be checked?

This arrived with no power. No obvious damage on the board. While measuring rails, they are all present up to PP3V3_S5 Diode mode on PP3V3_S5 is 0.008. Only 9.6 ohms. While injecting voltage only U1200 gets warm. On a side note PP1V05_S5 voltage is fluctuating Can this chipset can be...

u7220 showed heat when injecting voltage. Replaced U7220. Still 0V on PP5V_G3s but now is 38ohms

PP5V_G3S 5.2 ohm

This arrived with both CD3217s having burn marks on them from minor liquid on the usb-c connector. Fans were also spinning very fast at the time at only 5V but 1.5amps. No liquid damage on the board itself. Replaced both CD3217s board now has 20v but only using 0.06 amps. No fan spin now...

0V L7270 Bios from donar board did not make any differences