Maker Pro
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Ellusive microcontroller

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N_Cook

Jan 1, 1970
0
I'm trying to locate the overall system controller on a video board, that
handles IR remote, physical keypad functions and power on/off of main power
supply etc. Mulilayer board of course but all I can find is dedicated
digital video processing chippery. This is quite a thick pcb , does anyone
hide SMD controllers recessed within the thickness of a pcb? there is a
mysterious black piece of plastic in one area , well bonded to the pcb but
no outline of anything underlying it
 
N

N_Cook

Jan 1, 1970
0
I warmed up and lifted that patch and nothing hiding underneath. I've
managed to identify, surprisingly, all chippery , all 29 SMD devices with 8
or more pins and all are dedicated video /audio/MUX/memory /op-amp packs
etc, with pinouts etc avaialble for all , but no uC or PIC found for system
control
 
J

Jeroni Paul

Jan 1, 1970
0
N_Cook said:
I'm trying to locate the overall system controller on a video board, thathandles IR remote, physical keypad functions and power on/off of main power supply etc. Mulilayer board of course but all I can find is dedicated digital video processing chippery. This is quite a thick pcb , does anyone hide SMD controllers recessed within the thickness of a pcb? there is a mysterious black piece of plastic in one area , well bonded to the pcb but no outline of anything underlying it


It could be integrated in the video processor, it is in most digital decoders for TV.
 
N

N_Cook

Jan 1, 1970
0
N_Cook said:
I'm trying to locate the overall system controller on a video board, that
handles IR remote, physical keypad functions and power on/off of main power
supply etc. Mulilayer board of course but all I can find is dedicated
digital video processing chippery. This is quite a thick pcb , does anyone
hide SMD controllers recessed within the thickness of a pcb? there is a
mysterious black piece of plastic in one area , well bonded to the pcb but
no outline of anything underlying it


It could be integrated in the video processor, it is in most digital
decoders for TV.

+++++
And so it was. Although no schema for this unit , googling on the 2 main
"video " processor chips and filetype:pdf threw up a few detailed
schematics, to then targetted probe under the big BGA, to check traces.
Is there a special probe for doing this, thin , tough, insulated , with
graduations for indicating which row/column depth from the edge ?
 
J

Jeroni Paul

Jan 1, 1970
0
N_Cook said:
Is there a special probe for doing this, thin , tough, insulated , with graduations for indicating which row/column depth from the edge ?


I do not know, but it comes to mind you could use enamelled wire with the insulation removed on a small area at one end. Drawing a small scale on the wire may be the hardest part but if you are interested in just a few pins that reduces the number of marks to place.
 
N

N_Cook

Jan 1, 1970
0
N_Cook said:
Is there a special probe for doing this, thin , tough, insulated , with
graduations for indicating which row/column depth from the edge ?


I do not know, but it comes to mind you could use enamelled wire with the
insulation removed on a small area at one end. Drawing a small scale on the
wire may be the hardest part but if you are interested in just a few pins
that reduces the number of marks to place.


+++++
I have some .08mm tungsten wire that is just about stiff enough as a probe ,
for this Ti ADP2000 BGA could have been larger diameter, laquered over and
just the end ground down clean. A refinement I suppose would be contrasted
markings along the laquer for row/column spacings, I think up to 5 deep in
some areas of these
 
N

N_Cook

Jan 1, 1970
0
DDP2000, should have been , too much sun today
 
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