Looking for info on a Mitubishi TV mircoprocessor....

[Vector Viper]

I am working on a Mitsubishi 35" CK3551R console.
I need info on the processor on this unit (front controls, remote
decode, runs tuner too)
It is a M50441-564SP ( IC 701).
It has 5 volts, and the crystal is runnig, but will not respond
to buttons
or remote commands (the signal does make it to the input pin) It
may be locked up,
or the reset is not working?! ANY info on this set or the
processor would
be helpful... Thanks You,

Aaron H.

 

[JURB6006]

Negative supply to the EAROM, 910 ohms feeding a Zener. Blown by high SMPS
output, check all lytics on hot side.

Set will turn on but not back off correct ? If that is it, this is it. Use a 1K
if you have to, but the fried resistor is under a cloth sheath. Any thing like
that you'll find a negative voltage on one side and not much anything on the
other. You should see some darkening of the PCB under it, and DO NOT even plug
the set in until you fix the poiwer supply !

Shitty lil 100 or 10 uF caps IIRC, causes all of this. If you don't fix it
right, it'll be back for an audio problem. The SMPS towards the front of the
set.I think the SMPS should put out about 35V negative, if it's signaificantly
more than that, you're not done. Some caps on the secondary side also go bad.

JURB

 

[ligotti]

JURB,

I am working on a CK 3502R - Same issues indicated above - Can you please provide a bit more clarity on what needs to be done to repair? Is the resistor under the cloth a 100 ohm - known as R780?

What do you mean by SMPS?

I appreciate the help