20 Most Recent Sanyo DP42848 LCD TV - Page 5 Questions & Answers

This is definitely being triggered by the power supply. The repeated clicks and the set powering on and off are usually associated with bulging electrolytic capacitors on the power supply board inside the tv , which must have been caused by a surge. I suggest that you do not turn on your tv and try to remove the back cover of the tv to look for the caps that look like this
http://www.wheresmydrink.com/wp-content/gallery/may-2009/capci.jpg
Let me know what you found so that we can continue with the diagnosis

The problem can be the power supply (24vdc section) due to bad caps, bad backlights inverter boards, bad main board. You will need to do in-depth troubleshooting starting at the powwer supply section first.
Please read my guides to get more understanding on how the TV works.
If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on: Basic LCD monitor and TV troubleshooting guide: http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting http://www.fixya.com/support/r7406380-tv_training_manuals Failed TV and Monitors pictures: http://s807.photobucket.com/albums/yy352/budm Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague Parts: www.shopjimmy.com Parts: http://interliquidparts.com/ Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps. Or www.digikey.com, just make sure to use caps with low ESR, 105c, high ripple current and long life rating such as PANASONIC FM or FC series. Please post back what you find.

Depends on how the line looks like, but most of the time it's either the T-CON board or the LCD display itself.

If it's a brand new TV I'd say just go back and return it to the store for exchange.

Sometimes it is an easy fix. If you just need to replace the inverter, that is fairly simple. However the symptom could be a sign of the backlight having failed and those are much harder to replace.

If the problem occurs on all sources and the onscreen menus are not viewable, then the backlight system is suspect. (The backlight itself usually fades or makes the on-screen image change to pink/red.) With a bad backlight, you'll usually see a very dim image if you look at the TV from an inch away from the screen. Block the room light from overwhelming this image (sometimes a carefully positioned flashlight will help you see something). If the inverter or video board is bad, you will see nothing. For an out-of-warranty TV, open up the back of the TV and remove the shielding. Look for any scorch marks or bulging or damaged capacitors. (Sometimes other parts will fail on this part but these can be spotted easily. Capacitors look like cylinders on a tripod.) The scorch mark and smoke may indicate a resistor or zener diode that had been used as a fuse and is now gone. If it is in warranty, contact the manufacturer before voiding the warranty.

To diagnose an failed inverter, you need a high-end multimeter (able to measure high frequencies - 50 kHz) or an oscilloscope, hold the multimeter probes a fraction of an inch apart about an inch above the inverter board and power up the TV. If you see a 1 or an actual value, you have a good inverter. If you see a reading near 0, the board is bad or the multimeter can't resolve the frequency.

In either case, you can buy a replacement inverter for $50-150 and just do a simple swap. Disconnect all of the wires (connections are similar to molex and ribbon cables in a computer) and remove board (a few screws usually). Connect the cables to the new inverter. (If you google backlight inverter replacement, you'll find videos and text descriptions.) Note the part number on the board, including the Rev number, and order the exact one (shopjimmy.com or lcdparts.net are good starting points). Universal inverters do exist but can result in reversed controls (up to lower the brightness). Replacing individual parts on the board is cheaper but more prone to not tracking down all of the bad parts.

If the inverter is good, then it's probably backlights themselves (several in most TVs). These are sandwiched on the perimeter of the TV (usually under some tape that holds the lamp, reflector and other parts together. You need to order by length and width and get ones for your TV size. Separate the panel from the bezel. Remove the tape, and separate the reflector (make a note of how things are put together) then you have to Dremel (or use another rotary tool) to remove the plastic to get the backlight out. (They are often molded into the frame.) Then put in the new backlight and reassemble everything. See http://www.lcdparts.net/howto/default.aspx for more information but for an overview: http://www.inventgeek.com/Projects/BacklightFix/overview.aspx. Then push the new backlights into place, reconnect the wires and close up the sandwich of tape and other parts around the screen. Then replace it in the bezel.

With a good spare backlight, you can test an inverter for condition (plug together and turn on the tv while the box is open). Similarly a good inverter can test the backlight.

I hope this helps.

Cindy Wells

Your unit has a defective LCD panel. If the unit is not under warranty, the LCD panel itself will cost you about as much as the tv. Best solution is to replace the tv with a new one and always purchase an extended warranty.

Hi art_davis,
Power on the unit in the dark room then shine with the flashlight directly in the screen, you will barely see the images. This is because your backlight is not functioning. The following reason was the caused.
1. Power supply - missing B+(supply voltage) coming from this board feeding the inverter board. This is caused by faulty transistor, dried/leaky electrolytic capacitor, open fusible resistor.
2. Inverter board - even the B+ is good from the power supply, if the fuse, driver transistor, driver transformer is faulty no output to the backlight resulting to black picture.
3. Busted backlight - even inverter board is good but if this is busted resulting to black picture also.

Check the parts here.
Diagnosing the fault is technical and if you don't have necessary tools and test instrument and can't fix it yourself, I would advice you to look for an experienced technician to isolate the problem.
Hope I helped you.
Have a nice day!
Thanks for using Fixya.

hello tbelase,
That's panel problem. Inverter problem actually.
Change inverter can solve this problem.
good luck.

Hi Rob,
Power on the unit in the dark room then shine with the flashlight directly in the screen, you will barely see the images. This is because your backlight is not functioning. The following reason is the caused.
1. Power supply - missing B+(supply voltage) coming from this board feeding the inverter board. This is caused by faulty transistor, dried/leaky electrolytic capacitor, open fusible resistor.
2. Inverter board - even the B+ is good from the power supply, if the fuse, driver transistor, driver transformer is faulty no output to the backlight resulting to black picture.
3. Busted backlight - even inverter board is good but if this is busted resulting to black picture also.
Diagnosing the fault is technical and if you don't have necessary tools and test instrument and can't fix it yourself, I would advice you to look for an experienced technician to isolate the problem.
Hope I helped you.
Have a nice day!
Thanks for using Fixya.

It may have detected shorted circuits or just have bad power supply due to bad DC filter caps with domed tops. You need to open it up and troubleshoot it, so far I did not find free service manual download for it yet.
Please read my guide to understand what to look for inside the TV.
If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on: Basic troubleshooting guide here: http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting http://www.fixya.com/support/r7406380-tv_training_manuals Failed TV and Monitors pictures: http://s807.photobucket.com/albums/yy352/budm/ Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague Parts: www.shopjimmy.com Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps. Or www.digikey.com just make sure to use caps with low ESR, 105c, high ripple current, long life rating such as PANASONIC FM or FC series.

Hi, Sounds like either the power lead has not been pushed far enough into the TV or there is a dry solder joint that needs re-soldering or faulty component on the power supply board.

If the tv was dropped in transit there may even be a crack in the PCB. but if not probably the above.

Hope this helps.

Midge.

change the RCA cable and be sure to connector vedio to video audio to audio good luck

most likely a defective Z-SUSTAIN board failure if the video looks somewhat correct and the tv is just dark. the Z-SUSTAIN board basically powers the plasma panel and if it fails a certain way it will cause this problem with the dark video. if you can get the tv taken apart and look for part numbers off of the board on the far right looking from that back then you may be able to find the part on the internet somewhere otherwise Contact Sanyo Manufacturing Corp 1-800-877-5032. good luck

You may need a DTV converter, or setup channel scan for both analog TV and then digital TV?

The T-con board in your tv is the board that transforms the data coming from the image processor in a form that can be displayed by the LCD screen. In your case it is failing - a chip has started to detach from the board because it was badly soldered at the manufacturing stage. When the tv heats the solder points dilate and allow a partial contact. Since this cannot be fixed - you can't resolder the chip - the entire board will have to be replaced. This is going to cost you around $250, including the labor of the repairman.

you have the problem in the fly back transformer replace it

Unplug,replug tv an hour later.Tv it now resetting it self back to factory setting.Tv still have the same problems.The T-CON board is dead.This board is the board sit right at the bottom center of the LCD panel screen.Tries websites like Shopjimmy.com,Ebay.com to buy a refurbish T-CON board for the replacement.

Start with the aspect ratio button. There may be other issues, but this should gey you through the game. Hope this helps:)

Are you nuts TV is my second life ( first is internet ). I can't live with out turning on it. LOL !
Think this is helpful !

Hello,

Hi
A common problem for these is bad capacitors in the power supply, Remove the back from your Tv and look at the power supply on the left hand side.

You will see roughly around 9 x capacitors that are bulged / domed shaped on top usually these are valued at 3300uf 10V any that have bulged or leaked a brown like substance should be changed.
This will cure the problem as they overheat being sat next to a heatsink that gets very hot!
Try and change them for the same 3300uf but a higher voltage.
Hope this helps