Sony KDF-42WE655 DLP dumps autoprogram

[klem kedidelhopper]

I have a Sony KDF-42WE655 DLP set that recently stopped storing
channels. For the past 5 or so months our channel line up has
consisted of about 30 channels (we get basic cable) and about 100
channels of "no signal", black screens etc. I decided to run the auto
program option in the menu in hopes that some of these erroneous
channels would disappear. After the auto program completed, our
channel line up was great. It appears that after the set has been off
for a few minutes and turned back on I am greeted with a "no signal"
screen with no channels. In some cases the tv will not change
channels; ie when channel +/- is entered the last digit on the screen
will flicker but will go back to its original position. Interestingly
enough, when the set is turned off and immediately turned back on all
channels remain. It seems anything longer than 1 minute and the
channels dump.

What makes this equally interesting is that I have the same set in my
basement (55" version) that still has the entire channel line up. I
have not run the auto program on this in fear of the same thing
happening. Our 42" "works" but we have to run the 50 minute auto
program every time we watch to watch tv now. Any thoughts on what
might be causing this would be greatly appreciated.

Thanks, Lenny

 

[William Sommerwerck]

The obvious (though not necessarily correct) diagnosis is that whatever
"holds" the memory when power is off is failing to do so.

Look over the board with the tuner. If you spot a large CR-type lithium
cell, that's probably the problem. Replace it.

 

[[email protected]]

I have a Sony KDF-42WE655 DLP set that recently stopped storing
channels. For the past 5 or so months our channel line up has
consisted of about 30 channels (we get basic cable) and about 100
channels of "no signal", black screens etc. I decided to run the auto
program option in the menu in hopes that some of these erroneous
channels would disappear. After the auto program completed, our
channel line up was great. It appears that after the set has been off
for a few minutes and turned back on I am greeted with a "no signal"
screen with no channels. In some cases the tv will not change
channels; ie when channel +/- is entered the last digit on the screen
will flicker but will go back to its original position. Interestingly
enough, when the set is turned off and immediately turned back on all
channels remain. It seems anything longer than 1 minute and the
channels dump.

What makes this equally interesting is that I have the same set in my
basement (55" version) that still has the entire channel line up. I
have not run the auto program on this in fear of the same thing
happening. Our 42" "works" but we have to run the 50 minute auto
program every time we watch to watch tv now. Any thoughts on what
might be causing this would be greatly appreciated.

Thanks, Lenny

That's a LCD rear projection, not a DLP. Note the 'screen door'
effect. Training and service manuals are available free at
http://elektrotanya.com/?q=showresult&what=KDF-42WE655&kategoria=tv&kat2=all

It's unlikely channel information is stored using battery backed up
RAM, that went out in the 90's. Between the training and service
manuals you should be able to narrow it down to a single board. If
you don't have any luck isolating it to a signle IC, boards are
available on eBay

PlainBill

 

[klem kedidelhopper]

That's a LCD rear projection, not a DLP.  Note the 'screen door'
effect.  Training and service manuals are available free athttp://elektrotanya.com/?q=showresult&what=KDF-42WE655&kategoria=tv&k...

It's unlikely channel information is stored using battery backed up
RAM, that went out in the 90's.  Between the training and service
manuals you should be able to narrow it down to a single board.  If
you don't have any luck isolating it to a signle IC, boards are
available on eBay

PlainBill

Thanks for the link. Lenny