Forum > LCD TV forum

Sharp LC32D44 lcd tv

<< < (5/7) > >>

chrissie jones:
shall let you all know when i find out the prob!!. :dubbio:

brainstorm:
Hi Chrissie,

I got your message, and ive sent you the circuit diagrams

Brian

blackmail:

--- Quote from: Contrast John on May 08, 2010,16:01:21 ---Hi All
Managed to sort this one out. The lamp error counter had reached 5 which means the set needed to be started in service mode (hold down input and vol - on tv set whilst applying mains until the letter K appears on the screen, after which press vol - and prog - on tv set to get the service menu). Had no joy doing this though because the ccfl driver IC (BD9883 smd) was going into protection mode and preventing the backlight from operating. To get round this problem I overode the protection by fitting a shorting link across C7558 (smd capacitor) located near the IC. The set would now start in service mode.
Found that there are some test patterns available in the service mode one of which is a grey screen. Selecting this option showed the problem. The area across the centre of the screen was darker than the rest indicating the centre pair of ccfl tubes weren`t working. This chassis uses 10 tubes driven by 5 inverter transformers mounted in line with them, so before embarking on a tedious stripdown I ruled out the possibility of a duff transformer by swopping the centre one with one of the others. No change of course, so I dismantled the unit and checked the tubes and their holders for any visible problems. None were apparent but replacing the tubes cured the problem. Just needed to clear the lamp error and remove the link
Hope this info might be useful and thanks to the above contributors for the input.
Regards
John.



--- End quote ---

I am tring to short out the ic on this tv but I cannot for the life of me find the C7558 smd capacitor to short.
if you have got a picvture or ou could describe where the cap is located it would be greatly appreiciated.

I have looked at the picture in the thread annd that confused me even more because the capacitor is not at that location.

if anyone has the circuit diagram please could you mail it to me
thanks bm

Contrast John:
Hi bm
c7558 is located about an inch away from the BD9883 driver IC. Both are surface mounted components. Circuit diagram for the inverter is not included in the manual-seems to be the way these days. Service manual is available to download free here-

http://elektrotanya.com/

Regards
John.

JAYROD:
Very usefull bit of info regarding shorting out C7558 john. Have one in for repair whith same fault and now after shorting out C7588 i am able to see a slightly dark area across the screen approx a quarter of the way down from the top. Just wondering now if this will be as a result ot two tubes or just one being faulty. I think you said that you changed them as a pair,where they both faulty?

  Phil

Navigation

[0] Message Index

[#] Next page

[*] Previous page