Pioneer SD-P4044 problems.

[[email protected]]

Here's my dilemma: I have an old Pioneer SD-P4044 projection TV that
will go haywire after it has been on for a given amount of time. It
seems the longer it has been turned off, the longer it takes to happen.
Basically, the TV looks fine when first turned on, then after about
10-15 minutes each of the colors shift slowly apart (about 30 seconds
for the full effect), usually red heads east and green goes west, and
the sound lowers and eventually cuts out. The controls will eventually
become unresponsive and I have to unplug the TV in order to turn it
off. The TV still shows a moving picture, although you can hardly make
anything out due to the horrible color shift. I can't seem to find
anyone on the net with my exact issue, although I've seen plenty of
discussions on the 4277 convergence IC and bad solder joints. So my
question is - would the convergence IC failure affect the sound as well
as the picture, or do I have a completely separate issue? If its a
separate issue, what's the next thing to check/fix/replace? I've
already taken the power supply and convergence boards out and touched
up all the solder points. Thanks for any help.

David

 

[Rick]

Hey,
I suspect a heat problem - so BAD solder joint on the board..

I don't know the IC you mention 4277
who is the mfg?

Rick - Atlanta
KE4OCO

 

[[email protected]]

In other threads the IC is referred to as an STK4277, apparently the
chip under the heatsink on the convergence board. I didn't attempt to
remove the heatsink and verify that this chip exists in my TV, though.
The chip (or its replacement part) is only available from Pioneer, as
far as I can tell. I should mention all the caps on the board look
good, at least none of the tops are bubbled, and I can't see any burned
resistors. I freshened all of the solder joints on the board with no
luck. I thought I had found the culprit - a cracked joint on a large
cap on the power supply, but it didn't help. Apparently it was making
a "good enough" connection to work. Any ideas?

David - Memphis
KC4VRQ

 

[Tbird]

replace the system control ic. Pioneer p/n PDB010-C

 

[[email protected]]

Where is that IC located? On the main control board in the back of the
unit, or some other area? That chip is $50! You don't work for the
Pioneer parts warehouse do ya?