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From: PeterD on 17 Nov 2009 09:08
On Tue, 17 Nov 2009 12:21:13 -0000, "N_Cook" <diverse(a)tcp.co.uk>
wrote:

>Anyone know the likely current drain from 3V battery for a digital camera?
>Replaced as 1.5A and 2A fuses and taken BAT+ up to 1.8V, 1.5A supply and no
>signs of life.

I doubt you'll see life until you get much closer to the design
voltage (3.x volts). Until then the power supply/control circuits are
likely keeping it off to prevent undervoltage problems.

What are the battery specifications (output MA)? That would be a good
starting point: the camera would certainly not draw more than that
amount of current.


>F001 , rated S so perhaps 4 amp rating is the overall supply fuse, not blown
>previously so presumably I could try up to 4 amp. I assume its now a matter
>of finding a crowbar device somewhere connected to the 2 previous blown
>fuses . At least a diode in line with the bat+ line but not traced on
>visible surface of boards
>
From: N_Cook on 17 Nov 2009 09:52
PeterD <peter2(a)hipson.net> wrote in message
news:nfb5g5986jl1ecbnoo39hjg3qrpml7u585(a)4ax.com...
> On Tue, 17 Nov 2009 12:21:13 -0000, "N_Cook" <diverse(a)tcp.co.uk>
> wrote:
>
> >Anyone know the likely current drain from 3V battery for a digital
camera?
> >Replaced as 1.5A and 2A fuses and taken BAT+ up to 1.8V, 1.5A supply and
no
> >signs of life.
>
> I doubt you'll see life until you get much closer to the design
> voltage (3.x volts). Until then the power supply/control circuits are
> likely keeping it off to prevent undervoltage problems.
>
> What are the battery specifications (output MA)? That would be a good
> starting point: the camera would certainly not draw more than that
> amount of current.
>
>
> >F001 , rated S so perhaps 4 amp rating is the overall supply fuse, not
blown
> >previously so presumably I could try up to 4 amp. I assume its now a
matter
> >of finding a crowbar device somewhere connected to the 2 previous blown
> >fuses . At least a diode in line with the bat+ line but not traced on
> >visible surface of boards
> >

At the moment I'm following the heat.
Component marking
XR
5
F1
on the now accessed reverse side of the board,
perhaps 5V VTS designed to short , next job after scripting this , to try
and identify.
looks suspicious at the moment as far as heat is concerned and 2 apparent
supplies (separate traces) at switched rail voltage? fuse voltage common
anyway. Powered up for a few seconds to 2.5 amp 2.1V Bat+ on F001 and 2.0V
on all fuses, wheras cold testing there is 0.6 V diode test between them.
Main on/off sw is inactive as far as current drain being continuous, no
change on main sw setting


From: N_Cook on 17 Nov 2009 09:55
PeterD <peter2(a)hipson.net> wrote in message
news:nfb5g5986jl1ecbnoo39hjg3qrpml7u585(a)4ax.com...
> On Tue, 17 Nov 2009 12:21:13 -0000, "N_Cook" <diverse(a)tcp.co.uk>
> wrote:
>
> >Anyone know the likely current drain from 3V battery for a digital
camera?
> >Replaced as 1.5A and 2A fuses and taken BAT+ up to 1.8V, 1.5A supply and
no
> >signs of life.
>
> I doubt you'll see life until you get much closer to the design
> voltage (3.x volts). Until then the power supply/control circuits are
> likely keeping it off to prevent undervoltage problems.
>
> What are the battery specifications (output MA)? That would be a good
> starting point: the camera would certainly not draw more than that
> amount of current.
>
>
> >F001 , rated S so perhaps 4 amp rating is the overall supply fuse, not
blown
> >previously so presumably I could try up to 4 amp. I assume its now a
matter
> >of finding a crowbar device somewhere connected to the 2 previous blown
> >fuses . At least a diode in line with the bat+ line but not traced on
> >visible surface of boards
> >

second attempt

At the moment I'm following the heat.
Component marking
XR
5
F1
perhaps 5V VTS designed to short next job after scripting this , to try and
identify,
looks suspicious at the moment as far as heat is concerned and 2 apparent
supplies (separate traces) at switched rail voltage? fuse voltage common
anyway. Powered up for a few seconds to 2.1V Bat+ on F001 and 2.0V on all
fuses, wheras cold testing there is 0.6 V diode test between them


From: N_Cook on 17 Nov 2009 12:23
N_Cook <diverse(a)tcp.co.uk> wrote in message
news:hduddt$vv5$1(a)news.eternal-september.org...
> PeterD <peter2(a)hipson.net> wrote in message
> news:nfb5g5986jl1ecbnoo39hjg3qrpml7u585(a)4ax.com...
> > On Tue, 17 Nov 2009 12:21:13 -0000, "N_Cook" <diverse(a)tcp.co.uk>
> > wrote:
> >
> > >Anyone know the likely current drain from 3V battery for a digital
> camera?
> > >Replaced as 1.5A and 2A fuses and taken BAT+ up to 1.8V, 1.5A supply
and
> no
> > >signs of life.
> >
> > I doubt you'll see life until you get much closer to the design
> > voltage (3.x volts). Until then the power supply/control circuits are
> > likely keeping it off to prevent undervoltage problems.
> >
> > What are the battery specifications (output MA)? That would be a good
> > starting point: the camera would certainly not draw more than that
> > amount of current.
> >
> >
> > >F001 , rated S so perhaps 4 amp rating is the overall supply fuse, not
> blown
> > >previously so presumably I could try up to 4 amp. I assume its now a
> matter
> > >of finding a crowbar device somewhere connected to the 2 previous blown
> > >fuses . At least a diode in line with the bat+ line but not traced on
> > >visible surface of boards
> > >
>
> second attempt
>
> At the moment I'm following the heat.
> Component marking
> XR
> 5
> F1
> perhaps 5V VTS designed to short next job after scripting this , to try
and
> identify,
> looks suspicious at the moment as far as heat is concerned and 2 apparent
> supplies (separate traces) at switched rail voltage? fuse voltage common
> anyway. Powered up for a few seconds to 2.1V Bat+ on F001 and 2.0V on all
> fuses, wheras cold testing there is 0.6 V diode test between them
>
>

I don't suppose Exar have a list of topcodes anywhere


From: N_Cook on 18 Nov 2009 05:51
The SOT235 , 5 pin SM, topcode XR 5 F1 is probably a buck boost, an inductor
connects the 3V line to another of its pins. No Exar SOT235/SOT23-5 package
buck boost data found so far. Putting a 0.5 amp limited 3V supply to the
fuses on this board only, 2 ribbons disconnected to other areas, then
current drain is 60 to 90mA. I cannot decide whether to try reconnecting all
and powering from 3V, 4 amp or tracing back to wherever the main power
switch is. Switching main sw on/off/on made no difference to the large 2V
current drain


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