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  1. tlough75

    820-00840 PPBUS_G3H Short.

    I have on the bench a liquid damaged 820-00840 that had cola spilled on it. the 2 areas that were hit were U7650 and U7220. both PPBUS_G3H and PPBUS_G3H_CPU are 0.8 ohms to ground. Should I even bother injecting 1V, or should I kiss this one goodnight? I did replace U7650, C7651, R7865, C7689...
  2. tlough75

    820-3332 GPU Kernel Panic

    I have on the bench an 820-3332, so it is an Early 2013 15". the first time I saw it on my bench the screen would randomly flicker and the laptop would crash. I resoldered U8900 and it seemed to fix it, but a week later it is back on my bench. According to the customer, after it is running for...
  3. tlough75

    820-00281 Missing PP3V0_G3H

    So I have an 820-00281 that is at 20V. 30mA and has all the G3H rails up to PP3V0_G3H, which is at .01V and appears to have a 1.0 Ohm short to GND. Sadly thee liquid that I found was to the right of U1100. After looking at this rail rail. I see there only a few components and then U1100 and...
  4. tlough75

    820-01598 No power

    Hi, so on the bench I have an 820-01598 that is not powering on. I have 20V @ 40mA on my USB-C ammeter and PPBUS_G3H is 12.62V and PP3V3_G3H is present at 3.3V. I know since i have 20V at the charger the USB-C controllers are ok, and I have my G3H rails, I don't think my ISL is bad that probably...
  5. tlough75

    820-2936 No power, weird issue

    So I have on the bench an 820-2936 tonight and It has me stumped. With board only out on the table, when I plug in a MS I get no PP3V42 but has a light, PPBUS_G3H is 2.6V. On U6990 I'm getting 18v on pins 4 & 7, but no PP3V42_G3H. I replaced U6990 and at first it seemed to work, had MS light...
  6. tlough75

    820-00138 Random black screen

    On the bench I have an 820-00138 that has a strange issue. The backlight flickers and turns off, or stays on. BKLT_EN_R is 3.3V and BKLT_EN_L is 11V when computer is turned off but when I turn the machine on BKLT_EN_L goes to 7-8V and stays, even if I close the screen down. Does this mean U7701...
  7. tlough75

    820-2530 Not recognizing KB input/EFI Locked

    So I have an 820-2530 That is EFI Locked. I tried to perform a PRAM reset but it will not do it. When I plug in an external KB it will respond to me hold option to see the EFI padlock, but any other key combos I get nothing. I hooked and External drive to it and can see usb activity, I also...
  8. tlough75

    820-00165 Stuck on Apple logo

    So I have o nthe bench an 820-00165 that the customer said he took to another shop and they said there is a problem with the power distribution on the LB. I was like what?! never heard that before. I checked it out and asked for history and he said his daughter was using it and it just stopped...
  9. tlough75

    820-00840 Not powering on after UC

    So I have an 820-00840 that is not powering on. It was working, just had a couple corroded capacitor ends so I touched them up and UC'd the board. It now draws 0A @ 20V, but had PP#V# and PPBUS is 13.1V. Not sure what the heck is going on. Any suggestions?
  10. tlough75

    820-00840 - No Power (liquid damage)

    On the table I have an 820-00840 from a 2017 13" MBP. There was definitely some sort of spill in the liquid on the LCD connector, just some sticky stuff on the heat pipe for the CPU by the fan, and on the edge of the board by U2800. One USB port is showing 5v @ 5mA and the other shows...
  11. tlough75

    820-3437 Power on issue

    I have on the bench an 820-3437 with a power on issue. The customer told me that it would charge but not turn on so they replaced the battery. They said the owner used it for a bit but it started acting up so they replaced the battery again. I measured the G3H rails with only battery plugged in...
  12. tlough75

    820-3115 No chime or image.

    So I have an 820-3115 that has no image or chime. Iv'e checked all of the rails on the power aliases page in the schematic and found the only one that seems to be missing is PPVCORE_S0_AXG. it measures 0v. Shouldn't it be 1.05V?
  13. tlough75

    820-00165 Is my CPU really dead?

    So I have an 820-00165 that I pulled out of my "rabbit hole" box. I'm pretty sure it just needed a new U7701 and some solder mask repair. So I put a new U7701 but not it draws a steady 450mA but no chime amd no image. The only corrosion found was in the area of U7701. Now I am stuck with an LB...
  14. tlough75

    820-2796 Kernel panic

    On the bench I have an 820-2796 that had an EFI lock on it. I desoldered the EFI IC, soldered it to a little breakout board and backed up the BIOS then removed the EFI lock. Before I did this the laptop did not kernel panic and now it does randomly, and after every time I shut down after it...
  15. tlough75

    820-2532-A - Intermittent no power issue

    So on the bench I have an 820-2532 with a strange issue. It is usually drawing 40mA and not powering on, so I checked power rails and am missing PP5V_S3. I removed L7220 and injected 5v to mimmic the 5v rail coming from U7201 and then triggered SMC_ONOFF_L and the board started. I removed the...
  16. tlough75

    820-2850 Not Recognizing Hard Drive

    So. I have an 820-2850 on the bench that does not see the internal hard drive. I checked signals around J4501 and am getting 5v at L4500. I have tried 3 known good cables, and 3 different known good hard drives. Just get a flashing ? folder. Should I be looking for data signals now?
  17. tlough75

    820-00165 strange issue

    So I have yet another 820-00165 that posts to flashing ? has PM_SLP_S4_L but PPBUS is 8.18V. WHat the heck is going on here? This board has been messed with by someone else a little.
  18. tlough75

    820-00165 Missing PM_SLP_S3_L

    Got a sick LB from a customer. They foolishly bought it broken from ebay thinking they could save money and have me fix it. After inspecting it through the MS I saw that R1623, R1451, R1583 & R1462 were toast so had to replace and run a couple wires. Board is drawing 30 mA and not turning on...
  19. tlough75

    820-3437 Missing ALL_SYS_PWRGD

    So I have an 820-3437 drawing .100A and is missing ALL_SYS_PWRGD. PP5V_S4RS3 is missing, in fact , it seems I am missing all 4 PGOOD signals. No sign of liquid damage.
  20. tlough75

    820-00244 liquid damage

    Got an 820-00244 on the bench that suffered liquid damage on a couple parts by the CPU. They were slightly corroded so I plugged in the LB and in started out taking 0.06A @ 19.8V. after doing some measuring, it is drawing .06A @ 5V. I measured pin 1 and 4 of Q3100 and they are 11.1V and 7.24V...