Figured out the issue.
I noticed that when I powered it on this morning I briefly got 20V but was stuck at low current, current was 30mA IIRC. This was after removing C9586 but the capacitor was not shorted and didn't seem to be the cause of the change in behavior. While the charger was still giving me 20V i measured PPBUS_G3H and found it was at 12.3V. After a short while I lost 20V at the USB-C port again and it went back to 5V and cycling. The issue appeared to be related to temperature. Even though I did not get back 5V the ammeter would stop cycling if I warmed up the board....
Comp_Pro
Member
Last Activity: 11-26-2024, 05:01 PM
Joined: 06-19-2020
Location: Chicago
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No short but PPBUS_G3H missing 820-01700
Hello all,
I have this 820-01700 board which came in with 5V 0.015A on the ammeter. Ammeter cycles every 5 seconds or so. Upon inspection I found PPBUS_G3H is reading around 0.6V. There is no short to ground. Diode mode reading is about 0.420V. When I remove fuses F7000 and F7001 the U700 side of the circuit produces 12.3V and the cycling goes away on the ammeter but still stays at 5V and now reads 0A. This goes away as soon as I put back the fuses. I tried injecting voltage onto the system side of the fuse pads but I do not get any current draw at all. I tried seeing if the voltage... -
No Backlight Macbook A1990 820-01041
Hello all,
Am trying to figure out this backlight issue with this A1990 Macbook Pro.
Tests performed:
There is no backlight even with a good screen.
Backlight IC is receiving the correct support voltages.
Fuse F8400 ok
Current sense resistor R8400 ok
Backlight IC is receiving 3.3V on enable pin.
Backlight IC receiving voltage from PPBUS_G3H, aprox 12.5V.
Backlight IC receiving 5V from PP5V_G3S
Backlight IC BKLT_SCL and BKLT_SDA both measure 0.545V diode mode to ground
I2C_BKLT_SCL and I2C_BKLT_SDA both measure... -
U5850/U5870 I2C
Pin 9 SCL: 0.402
Pin 8 SDA: 0.400
Thanks for the heads up on the ultrasonic, did not know that. I've actually ultrasonic quite a few of them without any problem but will probably have to stop just in case.
I replaced the trackpad with no results. Still clocked down and has fast fan spin. Will attempt the DFU.Leave a comment:
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Thank you much for the valuable input. I'm not sure if the angle sensor is damaged or not, but my guess is no as I just discovered that the display actually does have an image but just doesn't have any backlight. I would imagine if the angle sensor was the issue the screen would not be turning on either correct?
Thank you mon2. Here are the measurements I took per your indications:
[B]RP873: [/B]All good, voltage on both sides of resistor.
[B]PPVOUT_LUXE: [/B]0V Diode mode 0.490 Diode mode with display removed: O.L.
[B]I2C_LUXE_DEBUG_SCL[/B] 0.362
[B]I2C_LUXE_DEBUG_SDA[/B]...Leave a comment:
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I ultrasonic cleaned the board. Yes I noted where the liquid damage was. Would there be thermal throttling if the trackpad was the issue? I know that will give you the fast fan spin but can't recall if I've seen that slow down the processor speed. Checked U5850 and U5870 but couldnt' find anything wrong as far as rudimentary testing, will have to haul out my O-scope to check I2C activity.Leave a comment:
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820-01949 Running Slow Fast Fan ASD Software Download?
Hello all,
I'm trying to repair this A2251 macbook pro. Board is 820-01949. The original issue was liquid damage which all cleaned up well and the board was not heavily damaged. Unfortunately after liquid damage cleaning the computer is running extremely slow and the fan is running at full speed. Even the cursor is lagging. Because of this I can't use the built in hardware diagnostic to give me a clue as to what is happening. Does anyone know if Apple Service Diagnostic software is available for this model? Any other clues which could help me out? Seems to me there is an issue with... -
So if I understand correctly, it's not possible to simply reset the existing angle sensor correct? A new one must be installed and programmed in order for it to work?Leave a comment:
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Macbook Pro M1 820-02100
Hello,
M1 Macbook Pro with 820-02100 board. Came in for liquid damage. Most of the liquid damage was located around UP800 backlight IC. Other than that not much other damage on the board. Computer turns on but shows no display. Originally I could get an image out of the HDMI port but now I only get a quick flicker when closing the lid and then the image disappears from the external monitor. In the brief moment I can see an image I do see the login screen. I tried re flowing and replacing UP800 with no luck. Do not see any shorts or other damaged components. BL_PWR_EN Is showing 1.22V... -
Macbook Air 820-00165 Static Chime Sound
Hello all,
I have a weird issue to solve here. This macbook air came in showing a black screen even though the backlight was lit. The display was not the issue as I tried another known good display. Upon trying to restart it, sometimes it boots up but freezes at the login page. More commonly however, the macbook will give the chime sound but then get stuck repeating the sound. The first chime sound is normal but the subsequent chimes sounds are crackly. Voltages seem normal, no liquid damage. I did find a blotch of something near one of the crystals on the other side of the CPU... -
PS5 HDMI not outputting CK/DA Signal
Hello all,
I am trying to repair this PS5 which came in with a shorted HDMI encoder chip. This issue was not allowing the PS5 to boot and would only beep upon pressing the power button. This is the first time I've had this issue despite replacing many many HDMI ports. After installing the new chip as well as a new HDMI port the console now powers on and appears to be booting all the way but there is no video output. Looking at my HDMI tester all signals are present except for DCC Clock and DCC Data aka CK/DA on my particular tester. These two have direct connections to the encoder... -
Re: playstation 5 digital firmware dump
NP! Glad I could help.Leave a comment:
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Re: playstation 5 digital firmware dump
Can confirm cloning the firmware worked on an identical CFI-1015A. I did not do any serial number changes or anything, just a straight clone. Upon first boot I did have to reset/restore the system however.Leave a comment:
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Macbook pro 820-00928-A Power but no Image
Hello all,
I have this macbook pro board number 820-00928 which appears to power on fine and charge the battery but does not show any other signs of life. I can see the fans spinning and the heatsink get hot. Most of the coils on the board have voltage except for PPVCCGT_CPU_PH1 and PPVCCGT_CPU_PH2 as well as P5VUSBCT_LL. There is no chime, no caps lock light, no nothing.
Something very peculiar is that with the battery disconnected, the motherboard is drawing a steady 1.31Amps at all times. It is not showing typical fluctuations as one would expect. I attempted... -
Re: playstation 5 digital firmware dump
Here is a firmware dump for CFI-1015A. Note that it must end A. Copied from known working and it helped me fix a PS5 that had 3 beeps as soon as you plugged in the AC cable. I believe the board was originally also going to 30mA and then shutting back down.
Upon boot it is now asking me to reset the software, will update to see if software reset/update will work....Leave a comment:
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Re: 820-02020 No Display, No TPAD, No USB, No KB, Fast Fan Spin
Thanks for heads up! Angle sensor was working when testing with external monitor. Could see a reaction. Really hope I don't have to deal with those new stupid angle sensors much.
Good news is the macbook is fixed! No display was just a bad lcd. Replaced and now fully working.
Thank you!Leave a comment:
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Re: 820-02020 No Display, No TPAD, No USB, No KB, Fast Fan Spin
UPDATE: Looks like it's a couple of dumb issues grouped together.
There was a metal flake in the battery data connector so computer was acting like the battery wasn't installed. After fixing this, trackpad, keyboard, and fast fan spin are all fixed. No idea why Apple designed these M1s this way. If you are working on an M1 macbook keep in mind keyboard and trackpad will stop working without a battery present. You will also get fast fan spin.
Display is still not working but now that it appears...Leave a comment:
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Re: Macbook 820-00850 20V 54mA No Power
bump. Anyone?Leave a comment:
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820-02020 No Display, No TPAD, No USB, No KB, Fast Fan Spin
Hello All,
This is a weird one. This M1 Macbook Pro was brought in for liquid damage. Customer was getting video only on external monitor. Most liquid damage was located around the backlight circuitry, namely the backlight capacitor bank. It was not too severe. Ultrasonic cleaned and about 3 corroded capacitors replaced. FP800 backlight fuse was also blown. Nothing down the line from the fuse is shorted. May have blown this fuse from overload during liquid being present.
Also had to repair area of QD530 which is PBUS VOLTAGE SENSE. Repaired traces to RD531 and RD532...Last edited by Comp_Pro; 05-10-2023, 02:41 PM. -
Re: Macbook 820-00850 20V 54mA No Power
Hello, thank you for taking the time to respond and I apologize for the delay to reply back. Since It's been busy here I had to shelf this one for a little while. Today I had some free time so I went back to it.
Voltage to ground on the enable line is 0.357 on both sides of the resistor R9082. It definitely seems however that the short is on the output side of coils L9080 and L9081. The low reading is on the output side of these coils when they are removed from the circuit.
Shorted NANDs? Unless it's a shorted cap...Leave a comment:
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