Chosen Solution
Hi experts, I have a 13” 2010 MacBook Pro. This machine has green light on the MagSafe and will boot with chime as soon as I plug in MagSafe charger. The screen stays black, but when I put in external monitor it will show the Apple logo and load about 1/3 and hang. So far I disconnected the internal HDD and tried to boot of external HDD, same result, boot and hang. I disconnected keyboard and booted with external keyboard, same. Did the SMC reset with no response, PRAM reset same, no change. I disconnected the battery and reconnected, still same. Disconnected machine’s display, to eliminate possible short in there. I’ve been told to: Try new BIOS, with clean ME. So I now have a EEPROM BIOS USB Programmer CH341A + SOIC8 Clip + 1.8V Adapter + SOIC8 Adapter at hand. I’ve been told by logic board repair gurus with very little patience for “noobs” that I MUST remove SPI chip U6100 and reprogram it with external programmer. I still do not know how exactly to reprogram U6100, if removing the chip is necessary, since I do have the jumper wire and clip, and in general looking for a link to show me how to do this without frying my board. And finally what is meant with: Upload somewhere your BIOS backup. I hope this is not too much to ask?? Update (12/07/2018) Oh, and I did run EFI ASD and it showed no errors… Update (12/08/2018) I had look under the logic board to see what I might find, and to check the power rails, as you suggested: So far I found amongst the regular chips: 1 Potato chip in a bed of dust, PPBUS_G3H: 12.59V PP3V42_G3H: 3.49V PPVRTC_G3H: 3.33V PP5V_S5: 2.22 V on various test points, Then I nearly burned my finger on L5801 which is on PP5V_S4_P18V5S5 (Booster for sensors) , which showed OL across the coil and short to ground on both sides. Could this be the culprit? And would replacing it might make a difference? While all this sounds very techy, I am still totally a “ noob”, but one with schematics and boardview….
PP5V_S5 at 2,2v , a shorted S4 line and a toasted coil are surely enough to prevent functioning. PP5V_S5 is a critical line, you’ll have to get that back working and get rid of the short before anything else. Luckily you didn’t get into Bios mess, would have just added confusion and probably driven you into a rabbit hole.
Lets backup here… What happens when you run the onboard diagnostics? Press and hold the D key during boot up Reference: Mac startup key combinations As far as reprograming the system BIOS why is that your first direction? What’s the systems history.
I would really love to see you try to boot from and external drive with El Capitan before you take more drastic fixes KISS (keep it simple)
