LT23D50 LT26D50 LCD problems

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andywilks
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LT23D50 LT26D50 LCD problems

Post by andywilks » Thu Sep 22, 2005 11:58 pm

Although I'm not claiming there's any real problem with this series of LCD tv's, which have a stunning picture on all the screen sizes.. much better than last years C50 /C51 series...
I've had one of each model with freeview problems. One locking up, requiring resetting every 1/2 hr.... the other has the freeview stuck on a black screen with a couple of pink and green stripes.

The 23" is a different chassis to the bigger sizes, but I assume the basic Freeview chipset is the same..

Still awaiting a resolution to these....

AW

matt1976
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jvc d50 lcd freeview fault

Post by matt1976 » Fri Nov 18, 2005 8:22 pm

you need the soft ware upgrade for the freeview fault

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andywilks
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Resolution to these sets

Post by andywilks » Sat Nov 19, 2005 10:29 am

Not as simple as that...

the resolutions are :

26D50 - locked up totally - eventually. It wouldn't take rs232 comms to try the software update- unit returned to JVC- not sure what was actually at fault.

23D50 different series- no software update possible/available. went back to JVC also. Have had another 23D50 with freeview blocking up and random sprays of 'dead pixels' - when its very warm. Memory IC proved to be very thermally sensitive. Maybe the other set was the same.

matt1976
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locking up

Post by matt1976 » Sat Nov 19, 2005 6:44 pm

have you tried to resolder the flash have had lots of problems with these

andyfras
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Re: Resolution to these sets

Post by andyfras » Wed Oct 17, 2007 11:45 pm

andywilks wrote:Have had another 23D50 with freeview blocking up and random sprays of 'dead pixels' - when its very warm. Memory IC proved to be very thermally sensitive.
I have this same fault on a "Bush" badged version of the same TV (chassis 17MB16P-1). I am still struggling to find the cause. To start with, it happened after the TV had warmed up, but now it is permanent.

I've had it to bits today and I've tried dabbing a low value capacitor around the digital tuner area, but with no improvement. It does feel like a capacitor problem though.

I may have to bite the bullet and order the service manual CD 13 from U View: http://www.u-view-circuits.co.uk/tv.html, but it is £59!

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Post by andywilks » Thu Oct 18, 2007 1:58 pm

Power supplies are the most likely to cause you problems like this. Scope the psu rails for ripple. If it has an external power supply block, that will be the problem... they are available typically 50- 80quid. Break it open and replace some caps as a cheaper option

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Post by andyfras » Thu Oct 18, 2007 4:16 pm

andywilks wrote:If it has an external power supply block, that will be the problem.
Thanks for the suggestion, but unfortunately not. I have scoped the 12V from the external PS and it is ripple free. I tried adding 2000uF across the output anyway, but no improvement. I also tried a 0.22uF polyester in case the output capacitor had high impedance to HF.

Maybe it's the 5V (or is it 3.3V or 2.5V) inside the TV? It's a major job to dismount it off the wall each time, so I may not get around to checking that for a day or two.

I should also add that when using the digital tuner, the menu is also affected, not just the received picture and sound. It works fine on analogue and with an external input.

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