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A1419 EMC 2546 Help Please
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- friedmonkey2
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8 years 5 months ago #1854 by friedmonkey2
A1419 EMC 2546 Help Please was created by friedmonkey2
Hey,
I'm trying to read from an imac A1419 EMC2546 but cannot get flashrom to pick up the chip. From what I've read the pinout is the same as in your tutorial, I've attached a pic of the chip a 25q064a.
I've been able to read/write to an MBP with the same setup with no problems. Is there something that needs to be done differently with the imacs?
I'm using rasberry pi with 8 pin pomona clip and flashrom. Any help would be appreciated!
I'm trying to read from an imac A1419 EMC2546 but cannot get flashrom to pick up the chip. From what I've read the pinout is the same as in your tutorial, I've attached a pic of the chip a 25q064a.
I've been able to read/write to an MBP with the same setup with no problems. Is there something that needs to be done differently with the imacs?
I'm using rasberry pi with 8 pin pomona clip and flashrom. Any help would be appreciated!
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8 years 5 months ago #1855 by xEngeLx
Replied by xEngeLx on topic A1419 EMC 2546 Help Please
Most likely, the clip is the problem. Either buy an expensive clip made by 3M or try to pry the clip pins that way the come out more from the clip and have a better connection to the EFI chip.
My bet is, if you press the clip harder against the chip, it will, at some angle&pressure connect properly.
My bet is, if you press the clip harder against the chip, it will, at some angle&pressure connect properly.
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8 years 5 months ago #1860 by CygnusX1
If I helped you buy me a latte!
Replied by CygnusX1 on topic A1419 EMC 2546 Help Please
That would be my exact diagnosis also.
If I helped you buy me a latte!
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8 years 4 months ago #1869 by thaGH05T
If I helped you, buy me a beer!!! Happy Hunting...
Replied by thaGH05T on topic A1419 EMC 2546 Help Please
I would also like to add that about 50% of the time people do not have sufficient voltage supplying their chip and/or programmer. You need to test the voltages at the clip and work your way back to the programmer. If it is not high enough (check your chips datasheet) then in some cases it will not read at all. Other times it will have bad reads and act funny. 3.3v is the optimum voltage for most 25 series chips. It is also notable that sometimes there may be a capacitor in line with the chip that will drain power from your programmer so applying battery power or the magsafe power supply may help.
If I helped you, buy me a beer!!! Happy Hunting...
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8 years 4 months ago #1873 by friedmonkey2
Replied by friedmonkey2 on topic A1419 EMC 2546 Help Please
Thanks everyone for the responses. I decided to cut out the clip altogether and solder straight onto the chip but still didn't get it to read.
BUT then I saw the reply from thaGHo5T and plugged in the main power and it's now working!! So thank you very much!
One more thing flashrom gives a message that the chip may have one-time programmable memory so may not get a full read, is this something to be concerned about or will it be okay?
Thanks.
BUT then I saw the reply from thaGHo5T and plugged in the main power and it's now working!! So thank you very much!
One more thing flashrom gives a message that the chip may have one-time programmable memory so may not get a full read, is this something to be concerned about or will it be okay?
Thanks.
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8 years 4 months ago #1874 by thaGH05T
If I helped you, buy me a beer!!! Happy Hunting...
Replied by thaGH05T on topic A1419 EMC 2546 Help Please
You should be good to go, do not worry about the message. I am glad I was able to help.
If I helped you, buy me a beer!!! Happy Hunting...
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8 years 4 months ago #1882 by
Replied by on topic A1419 EMC 2546 Help Please
That message is common for a few chips and I've read and written the same chip multiple times without a problem
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