820-3476-06 looping chime when lcd connected

Yoel Ren

Member
so I have this one 820-3476 which came in dead, no pp5v_s4, so I try to reflow smc, now the board came to life, does a looping cut out chime ( not complete chime)
tried all flex unconnected, no chime, and I sort it one by one, the culprit is the lcd, when I plugged it in, the chime loop came, but if not connected, it only chime once, already tried changing lcd connector, still the same..
 

Yoel Ren

Member
update : just realize the efi chip is maybe changed, its called mxic or something, it doesnt belong there is it
 
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Yoel Ren

Member
I use 820-3476a for 820-3476-06 because I don;t have similard board, the board can boot to windows 10, but very slow loading mac os, so it must be from the same exact board ?
sorry Im still a beginner at this type of work, do I just need to clean the me region then ?
 
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2informaticos

Administrator
Staff member
I didn't exactly understand.
Do you change BIOS file, or swap BIOS chip from other board?
In both cases, ME region MUST be cleaned...
 

Yoel Ren

Member
Mistype, I mean mxic at the comment above
I swap the chip from another board.. Is there any tutorial on how to clean me region?
I heard there's a manual way to clean me region too?
Whats the essential equipment to do these?
 
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2informaticos

Administrator
Staff member
You can clean it manually with any hex editor and correct Flash Image Tool from Intel.
If you plan to work Apple stuff, get Medusa programmer.
Can do the job very fast for you; as many more things too.

In the mean time, upload the BIOS file somwhere, so we can clean it for you.
I suppose you made backup of your original BIOS chip.
 

Yoel Ren

Member
i see, I think I'd take the medusa soon, how do I get the bios file ? fyi, jtag removed..
and I don't have reference to another working 820-3476-06, so Idk if the efi chip is already changed or not.., is it the mxic one, or the other one? or it doesnt matter, because you can just reflash it or something ?
 
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2informaticos

Administrator
Staff member
Should be good if you still have original chip.
You need to read it and check if still has original serial number on it.
If not, we build new one from the chip you've got the board started.

Remove U6100 and read it with an USB programmer.
We have various posts about how to read such chip without a special adapter.
https://boards.rossmanngroup.com/sea...%22wson8%22%7D
 
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Yoel Ren

Member
awesome, got medusa 3, and cleanme do the trick!
no more looping chime with / without lcd connected, now only no backlight
 
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