Analogue-sequencer

nothing...
I cannot enter in Upgrade Mode (FUNC+PAGE)
I'm always getting the checksum error (CHK FAIL = 7D5C)

is the IC marked P3-071 the culprit?

thanks
antonio

--- In analogue-sequencer@yahoogroups.com, "Colin Fraser" <colin@...> wrote:
>
>  
> > and at the startup I'm getting "chk fail = 7d5c" and p3 stops
> 
> There are two programs in the P3 flash ROM.
> The bootloader runs at power-on, checks to see if you are holding the keys
> to trigger firmware update mode, then checks the main program is OK.
> Then the main program is started.
> 
> Chk fail means the bootloader has found the checksum of the main program
> does not match the stored checksum calculated when the main program was
> first loaded.
> You should be able to fix this by re-loading the main program.
> That is, unless the power spike that seems to have caused corruption in the
> main program also caused corruption in the bootloader.
> The bootloader is only a small piece of code, so the chance of it being
> corrupted if a random byte in ROM is lost is much smaller than for the main
> program.
> If the bootloader is damaged, the only fix is to send the CPU back to me for
> brainwashing.
> 
> Best regards,
> Colin Fraser
> Sequentix Music Systems Ltd
> http://www.sequentix.com
>