How do I reprogram Mac BIOS chip exactly?
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??
Oh, and I did run EFI ASD and it showed no errors…
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,
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….