Hi all.
I've got a PCB here originally from a motorised robot car which
according to the manufacturers has a blown sound chip. The cpu does
seem to be working as the i/0 lines are being toggled and the crystal
is running on frequency, but is not responding to the trigger pins
even though they are being polled.

The CPU (whatever it is) has the crystal on two pins near the bottom
left of the chip, and the sound chip is a 44 pin quad flat pack. It
looks like the 5v regulator lost its ground pin and applied +8V to the
logic for an indeterminate time

PCB is labeled ST003 v2 if this helps.

Anyone seen this fault before? I really do not want to change a £150+
board for a £3 sound chip! (someone's sanded off ALL the markings grr)

The sound storage EPROM is a 24C002 (2 megabit) and that looks intact.

Thanks in advance,
-A

conundrum wrote:
Hi all.
I've got a PCB here originally from a motorised robot car which
according to the manufacturers has a blown sound chip. The cpu does
seem to be working as the i/0 lines are being toggled and the crystal
is running on frequency, but is not responding to the trigger pins
even though they are being polled.

The CPU (whatever it is) has the crystal on two pins near the bottom
left of the chip, and the sound chip is a 44 pin quad flat pack. It
looks like the 5v regulator lost its ground pin and applied +8V to the
logic for an indeterminate time

PCB is labeled ST003 v2 if this helps.

Anyone seen this fault before? I really do not want to change a £150+
board for a £3 sound chip! (someone's sanded off ALL the markings grr)

The sound storage EPROM is a 24C002 (2 megabit) and that looks intact.

Thanks in advance,
-A



Can you work out the pinout of the chip? Perhaps there's some
recognizable features that could point you to the manufacture?

hi, some times if you wet ya finger , then wipe it on teh top of teh chip ,
and use a strong light u might be able to make out some markings, i did
this to a chip , where the marking s where ground of , but they didnt do
a proper job.
mark k



"James Sweet" wrote in message
news:2n8Vh.8256$uF1.4065@trndny04...
conundrum wrote:
Hi all.
I've got a PCB here originally from a motorised robot car which
according to the manufacturers has a blown sound chip. The cpu does
seem to be working as the i/0 lines are being toggled and the crystal
is running on frequency, but is not responding to the trigger pins
even though they are being polled.

The CPU (whatever it is) has the crystal on two pins near the bottom
left of the chip, and the sound chip is a 44 pin quad flat pack. It
looks like the 5v regulator lost its ground pin and applied +8V to the
logic for an indeterminate time

PCB is labeled ST003 v2 if this helps.

Anyone seen this fault before? I really do not want to change a £150+
board for a £3 sound chip! (someone's sanded off ALL the markings grr)

The sound storage EPROM is a 24C002 (2 megabit) and that looks intact.

Thanks in advance,
-A



Can you work out the pinout of the chip? Perhaps there's some recognizable
features that could point you to the manufacture?