Re: Macbook A1989 / 820-00850 Restart problem
Thanks for your reply.
Already looked for corrosion, and the only place i found was in the IC i mentioned above.
This machine has integrated graphics, not a discrete card.
Thank you to the guys at HEGE supporting Badcaps [ HEGE ] [ HEGE DEX Chart ]
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Macbook A1989 / 820-00850 Restart problem
Hi,
I'm working on a A1989 820-00850 Logic Board.
The customer complained that the machine restarted randomly.
From the analysis I made to the Logic Board, I detected a small corrosion in the IC U7430.
Although the diode values are all correct, I replaced the IC with another one. But the machine kept the same problem.
However, I noticed that whenever I use the Heaven software, the machine restarts after a few seconds. That is, it is enough to have an increase in graphics processing for the machine to restart.
Has anyone had a situation...
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Re: Macbook Pro 13" A1706 820-00239 No power 20V 0A PP3V3_S5 not stable
I'm measuring PP5V_S5 on C7651.
P5VS5_EN also oscillating.
I already tested with 2 different U7650, same thing.
C7651-1 = 497,2Kohm (edited)Last edited by GfilipeZ; 08-31-2022, 10:30 AM.
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Macbook Pro 13" A1706 820-00239 No power 20V 0A PP3V3_S5 not stable
This Logic Board suffered water damage.
PPBUS_G3H = 13,09V
When i started to check S5 power rails stage, i found that PP3V3_S5 was not stable.
So I started to check from the beginning, SMC_PM_G2_EN. I took off R8110; then R9160 and finally U7650. Then i realized that PM_EN_PVXS5 only starts to oscillate when enter in U7650.
I already tested with 2 different U7650, and with same result. So i suppose is ahead of U7650.
Checked all power rails from schematic page 100 and 101, and no shorts, no low resistance.
Any ideas?
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Surface Pro 4 / X911788-008 / No power
Hi,
On Mosfet Q7002, is missing rail PWR_SL1_F_GATE 3,3V. So there is no voltage on the Board. That lead me to U3601 IT8528, and i found a short on +3V_EC.
I injected some voltage on that rail, then checked with thermal camera, and the IC U3601 was warming up instantaneous.
With the IC in place, the rail have 0,002 of voltage drop in diode mode. And there is no voltage present.
Without the IC, the voltage is present 3,3V. And if a measure in diode mode, the value is 0,080. Seems to low for that rail.
Anyone have that values, for reference?...
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Re: Macbook A1502 / 820-4924-A / Not always boot
Many thanks hoaca388!!!
I will give you feedback.
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Macbook A1502 / 820-4924-A / Not always boot
Hi,
I'm working on this machine, and like the title says, it doesn't always boot.
If I let the Logic Board for a while disconnected from the battery, most of the time it boots. But when I turn it off, and let the battery connected for 20/30*min it doesn't boot. And makes this all over again.
When it doesn't boot, the PM_SLP_S4_L is missing.
In the past, I had one A1466 with the same problem. And cleaning the ME Region solved the problem.
Can anyone help me cleaning my EFI ME Region?...
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Re: BY-U301 software and usb rom files requested
Hi,
T2 Rom file, for A1989 820-00850-A? Anyone?
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Lenovo IdeaPad Flex 5 14ITL05 didn't turn on / need help to setup SN and MTM
Hi,
I'm working on a laptop (i think) with a corrupted bios.
I installed a new file (from vinafix) with the programmer, but now i can't set the SN and the MTM.
Before i installed the new bios file, the laptop didn't power on at all. Now it power on, but doesn't recognize the ssd nvme. And i can't start XClarity Provisioning Manager to edit the SN and MTM (model).
Anyone know if a can do it with an Hex editor?
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A1466 / 820-3437-B / only starts on the 3rd attempt
Hi,
I'm trying to detect a strange anomaly that keeps repeating itself in the same way.
If i press the power button, the fan spins 1/4 and stops. I press the button again, and the fan spins normaly, but there is no boot. Then i force it to shutdown, and press the button for the 3r time, and the machine boots normaly.
If i let the macbook turned off for about 20/30 min, the anomaly comes again, and i have to do all again to make it boots.
I already tried an SMC from a donor logic board and dump a clean firmware to the EFI ic, but the problem always...
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Re: Macbook A1707 / 820-00281-A / Boot, but no image nor backlight
Hi,
PPVOUT_S0_LCDBKLT (no LCD) = 3,1Kohm
PPVOUT_S0_LCDBKLT (no LCD neither D8410) = 2,5Kohm
I injected voltage on the "cluster" (without LCD and D8410), to see if any capacitor warms up, but nothing happens.
After that, I checked again the resistance on PPVOUT_S0_LCDBKLT, and the value was 178Kohm.
So I found, every time I plug the display without power to the adapter, the resistance drops immediately to 1,8Kohm....
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