I am working an a MBA 13 2020 that has no display. The MacBook power on but no display. After Checking on the backlight I found out that the EDP_BKL_EN was missing. And this power enable was coming from the PCH. So that means this MBA board is no chance to bring it back to life? any suggestion would really appreciate. Thanks, MobileXt
-
-
Re: A12179 820-01958 Missing EDP_BKLT_EN
Remove all power -> check the resistance to ground of EDP_BKLT_EN. -
Re: A12179 820-01958 Missing EDP_BKLT_EN
Locate R0550 and measure the voltage on pin # 2. This is only to confirm that the trace for EDP_BKLT_EN is not broken from the PCH to the target.
Then remove all power, measure the resistance to ground of pin # 2 of R0550.
What is the reading ? Is it the same ~86K ? The resistor is a 100k value but perhaps while in circuit, the reading of 86k is normal.Attached FilesComment
-
-
Re: A12179 820-01958 Missing EDP_BKLT_EN
What is the measurement of the voltage on pin #2 of R0550?
Is it the same voltage as you are measuring at the enable signal rail?Comment
-
Board had no history of liquid; unsure of drop history, but no signs of damage of any kind worth noting.
Charger sitting at 5v/0a. PPBUS is at 1.9v-0.9v steady cycle (peaks, drains, loops). Confirmed CHGR_EN_MVR is missing, but DCIN was reaching ISL just fine, so replaced ISL--no change at all. Confirmed pp3v8_aon is also missing--and being unsure *exactly* which signal appears first (or if they are simultaneous), I inspected PMU/U8100 area and found no shorts, but also found PP3V8_AON_MPMU_ISNS_VIN missing (not shorted). Replaced U8100 just in case (have had them fail in weird ways),... -
Hi everyone,
I recently acquired this card from a seller who was selling a PowerMac G5 for parts. He mentioned that the video card was probably broken too.
Upon closer inspection, I can tell the reason why it won't work: it's missing a bunch of CAPS! (it's also missing an inductor - 1.0uH).
It's a nice card as it's one of the few AGP cards that will support 2560 x 1600 resolution on a PowerMac G5 using a 30" Cinema Display.
Looking at the card, it appears to be missing the following:
1x 1.0uH inductor - orange square
2x... -
Hey guys.
Need help with this one.
Fan not spinning due to missing PWN Fan signal.
Also 5 seconds from powering up it freezes, unless in BIOS.
But as soon as Windows starts to load, it will freeze.
CPU is COLD / Room temp when it freezes.
I've replaced the CPU, same problem.
Replaced SIO/KBC IT8987e and reprogrammed - same problem.
Replaced fan - same problem.
Replaced flex cable from board to daughterboard (which has fan connector on it) - same problem.
Checked the Thermal sensors around CPU and Board to the SIO/KBC and...08-19-2024, 05:22 PM -
Hello. I would need some advice please.
My son's MBP suddenly stopped working and is now only getting the green-then-orange light on Magsafe and no fan spin.
He brought the MBP into the house (22 deg C) from a very cold conservatory (-3 deg C) and turned it on straight away. The Mac suddenly died a few minutes later.
I examined the logic board and couldn't find any signs of water damage, corrosion, blown up components etc. Nothing was ever spilt on it, and the logic board looks immaculate.
I have already replaced the logic board with another... -
Hello,
I have re-soldered the loose pins on the RAM slot which is a common fault on these models..
It charges and turns on the power LED but is missing several voltages like RAM and CPU do not come up which I believe is due to MAINON & SUSON being missing to turn these supplies on..
What I am un-sure of is what is the ITC chip waiting for to send out these signals, what are the requirements?
I have checked these lines in diode mode and they seam normal -> 600.
I have checked to see if they come on for even a fraction of a second...
Comment