[flashrom] Re: cannot read/write thinkpad R500 chip AT25DF321

[Spenser Truex]

On 21/08/16 07:58PM, Alexander 'lynxis' Couzens wrote:
> Hi Spenser,
> > Issue is with flashrom though. Perhaps something about this chip in
> > particular? Any ideas moving forward?
>
> you should check the power supply and try to improve the signals of your
> SPI bus.
>
> power supply => either your power supply at all isn't sufficient or the
> spi chip draws too quick power that an additional capacitor (of
> the correct size) closer to the chip is required.
>
> signal => improve your cables, shielding, reduce EMI or
> desolder the chip and put it on a seperate board, etc.. Or reduce the
> spi speed, what you already did. Maybe use a different spi clip or
> solder cables on top of your spi chip instead of using a clip.
>
> in-system flashs are always special and depend on the PCB of your
> target board. Some boards aren't possible to flash at all. But you
> should be ok (there is a low chance of bricking).
>
> For sure there are bugs in flashrom. But usually it's power or signal
> integrity. If it's an bug within flashrom, I would also desolder the
> chip and solder it to a small debug board. So you could reduce other
> failures soures and test flashrom in a "known" environment.

Thanks for this, I got another SOIC clip since mine had degraded and
bent leads.

I am going to put in a T500 board in the R500 to make a frankenpad
solution, since T500 boards have always worked fine for me and only cost
$25.

I've made a couple dozen of these laptops and am very happy with the
process and demand.
> Best,
> lynxis
> --
> Alexander Couzens
>
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