I didn't further disassemble to take the bottom board off, but getting at those 3 screws both in and out was the trickiest part of the whole mod.
Unauthorized modification to fix hum
- Thread starter tumegpc
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I didn't further disassemble to take the bottom board off, but getting at those 3 screws both in and out was the trickiest part of the whole mod.
Can you elaborate a little on this? Did your fix cure the hum (for the most part)? I can't judge by the photos how to do this. It looks simple enough to re-solder a better copper wire in place of the crappily grounded one, but is this fix as easy as simply removing the cover and you can see the area inside that you need to re-solder without pulling have the radio apart to get to it? My eyes are bad and Do not want to have to pull radio apart to fix. I do not have an sds200 YET. I am putting off buying one till the manufacturer fixes the problems.
That mod was done before the "staticdischarge" fix was discovered. That mod helped with the hum but did not eliminate it, so do the fix that the RR member staticdischarge recommended. I've done it at least twice with success.
OH OK thank you!
I sent my Uniden SDS200 in for repair recently for the display flickering issue, but also mentioned the hum when using powered external speakers. I took detailed pictures on the inside of my scanner before I sent it in and again after the repair.
The below picture is before the scanner went in for repair.
The following three pictures are after the scanner came back from repair. They show cooper foil was added on top of the grounding clip, hot glue added to both end of the ribbon cable connecting both circuit boards, and a short ground wire added. These fixes took care of all my issues including the hum when using powered external speakers. Uniden Repair did an excellent job. They also replaced the display.
Copper foil on ground clip for the external speaker hum.....
Hot glue on both ends of the ribbon cable
Ground wire for the external speaker hum issue....
The below picture is before the scanner went in for repair.
The following three pictures are after the scanner came back from repair. They show cooper foil was added on top of the grounding clip, hot glue added to both end of the ribbon cable connecting both circuit boards, and a short ground wire added. These fixes took care of all my issues including the hum when using powered external speakers. Uniden Repair did an excellent job. They also replaced the display.
Copper foil on ground clip for the external speaker hum.....
Hot glue on both ends of the ribbon cable
Ground wire for the external speaker hum issue....
I think this is a good "remedy" to reduce the hum problem. Though it may not technically qualify as a "fix" if the results are a much lower hum
then that's what matters, it's what your ears actually hear not what an oscilloscope measurement says.
The real point here is how in the world can Uniden produce many (if not all) $700 scanners that have obvious audio hum problems?
then that's what matters, it's what your ears actually hear not what an oscilloscope measurement says.
The real point here is how in the world can Uniden produce many (if not all) $700 scanners that have obvious audio hum problems?
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Very interesting, thanks for taking it apart and sharing that. The copper tape of course was widely used by many of us after the mitigation device was released. Also people did use the ground wire.
There was some thought that the display flickering was secondary to the introduction of the mitigation device but I have not seen any proof that the two are related. It looks like they took measures to prevent further problems with your display also.
What I find puzzling is why they don't do the simple StaticDischarge permanent fix so that the mitigation device could simply be removed as it would be irrelevant at that point.
Again, thanks for sharing, glad they fixed it for you!... Bob.
I'm not sure I'd want Uniden to perform this fix. Not sure if this is epoxy, wax or something else. It looks like a one time fix that might damage the ribbon cable and/or socket if it need to be repaired again in the future.
I agree!
Uniden used simple hot melt glue on the ribbon cables at manufacture time for years. But whenever I'd open one up a few months later, the hot glue was usually no longer sticking to anything other then the ribbon cable itself. It did not stick to the other surface so in reality, it probably did not help. Maybe they only intended it to hold the ribbon cables in place during shipping to the dealers back then!
The stuff in your picture is a lot darker (yellower) than the old hot glue Uniden used. The old stuff had a more white or clear color about it. I'm not positive but I think some of today's lower temp hot glue sticks also have a similar yellower color as what your pic shows.
If it sticks as good as the old stuff, you have no worries removing it as it will probably just pick right off!
If it gets down into the contact area though, that would probably be very bad and near impossible to remove unless it's a soft wax.
I worked on some larger coils that a previous owner had 'fixed' in place by filling them with hot melt glue.
They were a mess! I put the board in a pot of boiling water and that got rid of some of it but not enough.
I then put the whole thing in an oven set below solder melting point and that worked pretty well. The coils still had a very thin film of hot melt glue on their surface when done though. It was enough for me to do my repairs.
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