MicroGem DTV converter gets pretty hot

I just bought a used MicroGem DTV converter at an auction. The price
was right, and it works ok. But I noticed that it gets pretty hot
compared to my other converters (other brands). I also read on
several websites that these converters are known to die in a short
time because of excess heat, and many were sent back to the
manufacturer for replacement. Because of the way I bought it, there
is no warranty. Rather than let it burn out, I would like to add a
heat sink to whatever part(s) gets hot. Does anyone know what part(s)
overheats? (I might also enlarge the tiny holes in the case, or maybe
even install a small fan (like a CPU fan, if there's a proper voltage
source to run a CPU fan).

Thanks

Frank

 

On Wed, 30 Jun 2010 14:39:01 -0500, franksmith@nospammie.com wrote:

I just bought a used MicroGem DTV converter at an auction. The price
was right, and it works ok. But I noticed that it gets pretty hot
compared to my other converters (other brands). I also read on
several websites that these converters are known to die in a short
time because of excess heat, and many were sent back to the
manufacturer for replacement. Because of the way I bought it, there
is no warranty. Rather than let it burn out, I would like to add a
heat sink to whatever part(s) gets hot. Does anyone know what part(s)
overheats? (I might also enlarge the tiny holes in the case, or maybe
even install a small fan (like a CPU fan, if there's a proper voltage
source to run a CPU fan).

Thanks

Frank

The original power supply supply may not have the spare capacity to
run even a small fan. You might be better served with a fan powered
by a wall wart of the proper voltage.

John

 

[William R. Walsh]

Hi!

Out of all of the ideas you suggested, I recommend the fan. It's
likely to do the most good of anything, especially since there are
probably already heatsinks in there.

The two things that will produce the most heat in these are the power
supply and the video decoder/system processor IC. Capacitors in the
power supply may be situated too close to hot-running components or of
poor quality. If that's the case, I'd actually suspect some
combination of those issues. Provided nothing blows up, bad caps could
be replaced with better ones and that might be all you'd have to do.

On the other hand, if the video processing system on chip is getting
too hot and burning out, that's going to be almost impossible to fix.
Some run cooler than others...the LG chips seem to run so cool they
don't even require a heatsink while the ones from Zoran must have a
heatsink and it gets so hot that you can't touch it after just seconds
of operation.

If you have a simple voltmeter and know how to use it, you should be
able to find suitable power supply voltages to use for the fan. Be
extremely careful--parts of the power supply are connected directly to
the power line and will buzz/hurt/kill you. Voltages may also be
marked on separate boards.

If yours has the power supply and television tuning circuitry all on
one board (as some do), you'll have to trace the circuit to find out
where the power supply outputs are at.

William

 

[G-squared]

On Jun 30, 12:39 pm, franksm...@nospammie.com wrote:

I just bought a used MicroGem DTV converter at an auction.  The price
was right, and it works ok.  But I noticed that it gets pretty hot
compared to my other converters (other brands).  I also read on
several websites that these converters are known to die in a short
time because of excess heat, and many were sent back to the
manufacturer for replacement.  Because of the way I bought it, there
is no warranty.  Rather than let it burn out, I would like to add a
heat sink to whatever part(s) gets hot.  Does anyone know what part(s)
overheats?  (I might also enlarge the tiny holes in the case, or maybe
even install a small fan (like a CPU fan, if there's a proper voltage
source to run a CPU fan).

Thanks

Frank

Unplug it from the wall and remove the cover screws to get inside.
Leave the cover on and run it for an hour or so to heat it up. Unplug
it from the wall and remove the cover and find out where it's really
warm. You might not even have room to add a fan but they come in a
wide ranges of sizes and power capacity as shown in the DigiKey
website. It's actually difficult to build a power supply with such low
capacity that there _isn't_ spare capacity to run a fan.Also keep in
mind that the fan will _increase_ the supply capacity as it's heat
that is the limiting factor and you're getting rid of it. Now if the
fan STALLS you have extra problems.

G˛