Event EZbus digital mixer not booting , LCD message says: "b

[N_Cook]

Chris Tansit <tansi@keyweb.com> wrote in message
news:4bcd6a51$0$10914$c3e8da3@news.astraweb.com...

N_Cook said..
clocks presumably related sum and diff fashion with the
crystals 22.579200 and 24.57600 the CLK3 seems to come
from the USB chip with a 12MHz crystal associated
with it, will have to explore the Cypress datasheet

So no luck on the reset? It has stored config somewhere right?
If so it has to have some way of resetting a config then.

I'd still go with a flash but I would be hesitant to do that
without resetting first (if possible).
I've found most resets codes are unpublished.
Try to find out who the service agents were for them as well.

Two more things about the firmware.
If it does allow USB boot recovery (e.g. the firmware fails at some
point in post) it is either going to fix the problem 100% or due
to an underlined hardware problem do nothing.
Hopefully if its truly a proper boot recovery it works before the
code interfaces to the hardware.

I think either way software or a hardware hang flashing it
will not make you worse off if its your only option.

CLK3 , not from the USB chip, comes from VCO o/p of U3, a 74HCT4046 , whose
sig in comes from U29 an 04 inverter whose input comes from pin33 of the
CPLD functional blocks, which is firmly stuck logic H so vicious circle of
inactivity.
Incidently TP4 of 8 is the only one with any activity on , one of the approx
22MHz clocks.
Will have to leave exploring this for a while and get back to bread and
butter work, but any suggestions for hardware checking in the meantime,
welcome

 

[N_Cook]

N_Cook <diverse@tcp.co.uk> wrote in message
news:hqjqsm$dhj$1@news.eternal-september.org...

Chris Tansit <tansi@keyweb.com> wrote in message
news:4bcd6a51$0$10914$c3e8da3@news.astraweb.com...
N_Cook said..
clocks presumably related sum and diff fashion with the
crystals 22.579200 and 24.57600 the CLK3 seems to come
from the USB chip with a 12MHz crystal associated
with it, will have to explore the Cypress datasheet

So no luck on the reset? It has stored config somewhere right?
If so it has to have some way of resetting a config then.

I'd still go with a flash but I would be hesitant to do that
without resetting first (if possible).
I've found most resets codes are unpublished.
Try to find out who the service agents were for them as well.

Two more things about the firmware.
If it does allow USB boot recovery (e.g. the firmware fails at some
point in post) it is either going to fix the problem 100% or due
to an underlined hardware problem do nothing.
Hopefully if its truly a proper boot recovery it works before the
code interfaces to the hardware.

I think either way software or a hardware hang flashing it
will not make you worse off if its your only option.




CLK3 , not from the USB chip, comes from VCO o/p of U3, a 74HCT4046 ,
whose
sig in comes from U29 an 04 inverter whose input comes from pin33 of the
CPLD functional blocks, which is firmly stuck logic H so vicious circle of
inactivity.
Incidently TP4 of 8 is the only one with any activity on , one of the
approx
22MHz clocks.
Will have to leave exploring this for a while and get back to bread and
butter work, but any suggestions for hardware checking in the meantime,
welcome

From the R&C of the 4046 CLK3 must be about 200KHz, I wonder what would
happen feeding 200KHz or so into the PLL ? something to try on next powering
up