Hah, I think it'll be getting a bluetooth board stuck in it now, its got an aux input I can commandeer - if I can find a 5v rail on the board I'll stash it inside somewhere
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geoff69
Member
Last Activity: 08-08-2023, 05:18 AM
Joined: 12-16-2019
Location: london
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Re: dewalt battery powered radio - no power at board
Hah, I think it'll be getting a bluetooth board stuck in it now, its got an aux input I can commandeer - if I can find a 5v rail on the board I'll stash it inside somewhere...
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Re: dewalt battery powered radio - no power at board
SOLVED
Replaced output pmos NCE40P13S and now working
R5 looked suspect as measured only 674ohms vs expected 2M ohm and is across the gate and source
Thanks for all your help...Leave a comment:
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Re: dewalt battery powered radio - no power at board
From what I can tell >
If it is that particular voltage detector and not something else …
There is a voltage detect value in this case defined at 3v with upper and lower hysteresis values to prevent oscillation. Vdet being 3v with min -Vdet and max +Vdet
If vdd is below operating voltage the output is undefined
Otherwise output follows Vdd or Vss depending if Vdd is above or below Vdet - switching on the upper and lower bounds of +-Vdet values...Leave a comment:
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Re: ICE3B0365J Troubleshooting (W200 Sub)
How you getting on with this?
I'm tackling the same board and just waiting on caps to arriveLeave a comment:
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Re: dewalt battery powered radio - no power at board
I've tried to draw out the circuit from the left hand side of the board
I've taken the values of the resistors as measured and they're close to the smd codes
transistors are two channel p and an n
Is it any help? I can't follow whats happening...Leave a comment:
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Re: dewalt battery powered radio - no power at board
in which case we have
4.1v VDD Pin 2
3.7v OUT Pin 1...Leave a comment:
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Re: dewalt battery powered radio - no power at board
ahh interesting
if thats correct it would make sense that it uses the differential between battery + and pin c3 on battery to detect single cell voltage and cut off if below 3v?
on a fully charged battery I have >
pin 1 - 18.67v
pin 2 - 20.5v
pin 3 - 16.42v
Vdet is essentially 4.1v in this case referenced to battery pin c3 rather than battery negative - and I'd expect VOut to follow Vdet which it isn't?
The short I had between...Leave a comment:
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Re: dewalt battery powered radio - no power at board
Seem to be same as initial measurements
on a fully charged battery >
pin 1 - 18.67v
pin 2 - 20.5v
pin 3 - 16.42v...Leave a comment:
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Re: dewalt battery powered radio - no power at board
all resistors look sensible values
found short between two pins of the little (sop25?) 5 pin ic
re flowed and removed the short but still not joy
anyone know what this ic is and what its doing?
Marked B8PW but google isn't having any joy...Leave a comment:
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Re: dewalt battery powered radio - no power at board
There's no comms going to the board, just a two pin output - no enable signal
The fet needs a differential between gate and source to turn on - spec says typical -2.5v
Tested it has battery voltage at both...Leave a comment:
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Re: dewalt battery powered radio - no power at board
Nothing, test points?
Here are images of the reverse of the bird and also the board in situ showing no contact with anything else...Leave a comment:
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Re: ICE3B0365J Troubleshooting (W200 Sub)
Common faults on these boards - sounds like you've checked some of the caps.
The 5 output caps and three diodes of the smaller transformer. Caps can look fine physically but still be crapped out.
The large 5w 51ohm resistor.Leave a comment:
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dewalt battery powered radio - no power at board
Hi hoping you can point me in the right direction
Powerboard not outputing voltage to main board.
Looks like battery voltage comes in and runs through a battery discharge protection circuit triggering a P-Channel Mosfet NCE40P13S for output to main board.
Uses C3 pin on battery which I think is one of the cell voltages
Input from battery is 20V fully charged
Seems like there is full battery voltage at the gate of the mosfet, nothing on the drain and full battery again on the source which doesn't seem right.... -
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howdy, here I am introducing myself
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