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Equipment Repairs => LCD TV forum => Topic started by: monstermonkey on September 27, 2010,05:48:33

Title: LTW42DV
Post by: monstermonkey on September 27, 2010,05:48:33

Hi All, I have a KTV LTW42DV that won't turn on, I get a red LED standby LED and no flickering LED when I press the remote, the set won't come out of standby.

I've visually checked the caps, all seem fine, I managed to find a service manual for the set and have followed the trouble shooting guide to no avail - it's pretty basic and suggests fitting new PSU or mainboard.

This set appears to be sold under other brand names, hopefully someone on here will know of a repair.

The PSU has the numbers RDTL4200PS screen printed on the board and has a part number on the back 11141082 - the Hyundai version of the service manual has the number NOS-PA-42 (LTW42DV/DW)

Other similar model numbers seem to be LTW42D LTWD42DW

Can anyone help? I'm happy to donate beers to the source of a working repair - I'd even send the PSU off for repair if need be.

Thanks
Andy

Title: Re: LTW42DV
Post by: monstermonkey on September 27, 2010,08:40:49

Okay, I've had some more time on this and added an external 5v standby supply, the set now powers on and appears to work as it should, so this is pointing me to the 5vSB supply having failed.

Checking the 5vSB line shows 3.6 volts.

If I post a picture of the PSU could someone point me in the right direction?

Thanks
Andy

Title: Re: LTW42DV
Post by: Turnip on September 28, 2010,12:02:08

Hi Andy,

Go on - post a piccy - we love 'em - Chris.

Title: Re: LTW42DV
Post by: monstermonkey on September 28, 2010,13:24:17

Cheers Chris, pic as requested:

(http://www.pitbikeclub.co.uk/garage/images/4862/1_IMG_0426.JPG)

http://www.pitbikeclub.co.uk/garage/images/4862/1_IMG_0426.JPG

Title: Re: LTW42DV
Post by: alain28 on October 08, 2010,02:03:20

Hi Andy,

5v STBY PS trouble is 2 chemical capacitors.
(on the picture near left of the small transformer in the middle bottom)
Replace by 105°c "low esr" type.
Original should be 47uF, to increase reliability use 16 or 25v model and 100 uF value.

RDTL3200PS, RDTL4200PS, RDTL-3700PS have the same 5v stby trouble

Now it seems some design fault on RDTL3200PS (very similar design but not the same parts list (for each board code)) Voltage rating of resistors are over....
For PFC I have a very recent example of PFC voltage divider with input resistor cutted.(1 M metal film)
Main problem is that blows out fuse, PFC power transistor, PFC controller IC....

I have just repaired the PFC section. But now the main power 24v  looks ok but a little high as the 12v (more higher).
Also the regulation don't work...

AM

about RDTL PS http://alain.mionnet.pagesperso-orange.fr/ii3210sh.htm
not yet updated with PFC
english  http://alain.mionnet.pagesperso-orange.fr/enii3210sh.htm
less updated...

Title: Re: LTW42DV
Post by: monstermonkey on October 08, 2010,06:29:23

Hi alain, thank you for you very helpful reply.

I'll pick up some capacitors today and fit them tonight.

If this works, I'll be happy to send you a beer  :brinda:

Title: Re: LTW42DV
Post by: monstermonkey on October 09, 2010,03:08:30

Alains' tip worked like a charm, the TV is now working 100%.

Alain: as I said via email, if you let me know your Paypal address I'll gladly send you a beer  :brinda:

Title: Re: LTW42DV
Post by: fmgmagnus on December 27, 2013,04:21:29

Hello! I also have a problem with this card (((burned capacitor ((((Who can tell what the realties denomination there!?
Hello! I also have a problem with this card (((burned capacitor ((((Who can tell what the realties denomination there!? Blue, below the large transformer! HELP!!