20 Most Recent Sharp LC42D65U 42 in. LCD HDTV Questions & Answers

The power supply board has some electrolytic capacitors that have gone bad. Put a new power supply board in it. You can get it here : TV Parts Universal TV Stands DLP Chips ShopJimmy

This sounds like a very common issue.If set is hard to turn on (takes several tries)but will eventually turn on hereis what my guess would be.Every set has a standby power supplythat is running 7/24 if the set is plugged in and it supplies voltage to theremote circuit that turn on the main power supply for the tv and hence turn theset on.This is an area where companies cut corners by using lower rated voltage caps.By this I mean Standby usually provides under 10 volts to trigger the seton----what they do is use filter caps rated at say 10 volts max in a circuitwith 9 volts (example)=with the standby on all the time the filter caps(electrolytic caps) dry out and fail.The problem usually begins where you have to turn set on or or two times andgradually gets worse--takes longer and more tries to get it to come up.Once on it will stay on until turned off for a period of time.The caps will begin to work better (regain some of thecapacitance) as they get hot--hence one it is on it will seem ok.The beauty of this problem is most of themhappen when set is a year or two old (no warranty) and all you have to do islook at the top to locate bad ones.They are generally black or blue and round and vary in --they have twoconnections each--a + for positive and a - for negative--not unlike a batterywhich in a way they are. The + and - are marked on top and bottom of most boards.They are easy to replace and not expensive parts.The tops are silverand metal looking with creases on top and if bad they will be puffed up ontop---tops must be perfectly flat with no brown material leaking top or bottom.If this is your problem once you id them (make a drawing) you can begin.Here is the critical part---on each cap is also marked the value like 220uf 10vdc---220 micro farad at 10 volts maximum.If you find for example 6 puffed up and all are 10 vdc replace them with thesame value capacitance (like the 220 uf) but go up to at least in this case(from 10 volts) to a 16 or higher rated voltage cap.The only issue is when you go up in voltage rated value the cap is larger sosometimes there is an issue of physical space for the replacement on the boardto fit them in.The reason they cheapen these sets in this way is if 10 caps and you make25,000 sets there is a considerable savings in parts cost. They do not care as long as it lasts past the usual one year parts warranty.I have taken the time to be long winded because this really sounds like it maybe the problem you have.See attached photo of a typical cap and if you have questions or need advicelet me know.

Almost all sets that have buttons on front or side can have a issue like this----if you have a menu button on the actual set itself--it most likely is the problem.What happens is under each plastic button is a tiny "micro switch" that is a momentary switch that the plastic button engages only when pressed.They can have the normal feel when pressed and look ok---and in almost all instances they are the issue--seen ones where vol when up or down on its own or channel or even input.the switch has reached a point where it makes internal contact without being pressed--hence momentary.Only way to prove this is get at the switch inside the set and unsolder it to take it out of the circuit---This usually stops the problem and you can leave it out and use the remote or replace the entire strip with all the switches/buttons---In the old days you used to be able to buy just the switch but most sets now only sell the entire circuit board with the buttons/switches.

The caps are marked with a plus and a minus side--polarity.The caps are marked with values on them like 1,000 uf @ 10vdc= 1,000 micro farad at ten volts DC max working voltage.Each has two leads as indicated above and must be unsoldered and replaced and then soldered back in.Pretty straight forward stuff.bad caps usually will be puffed up a little or a lot on top.good on left and bad on rightArrows point to real bad ones---see others also puffed and others perfectly flat on top.

Now tv turn on have power LED and OPC LED lights indications flashes together?Yes,this problems,it is the tv Tuner signal board it is causes and the problems.That the board where the incomming broadcasting signal cable plug into it.If turn tv on.No power LED light or any kind LED lights at all.Yes.Than the tv power supply board that the cause and the problems,that the board where the tv power a/c cord plug into it.U have some basic mechanicals skills like take things aparts and putting it back together again?Yes,tries websites like Shopjimmy.com,Ebay.com to buy a whole refurbish tv Tuner signal board or tv power supply board for the replacement.

U already change the remote control for brand new batteries wright?Yes.Remote controls devices are heavily depend on it CPU chip for all of it functions.Test the tv manual buttons like Power,Menu,Volume - + and Channel + - all work?Yes.The tv remote control CPU is dead that why doesn't read the tv infered laser signal at all.Try website like Remotes.com to buy an original remote for the replacement.

Hello,

The issue you describe is consistent with a power supply board issue. This is the board where the AC goes to. This problem may have occurred as a result of irregular power supply, or excess power supply or power surge.

The TV is receiving current but cannot circulate or transfer the current to other necessary part of the TV because of the defective power supply board.

I do not think it needs replacement, rather some defective capacitors are causing this issue.
Open unit up and take a look at the power supply board.You will probably see one or more electrolytic filter capacitors that are bulged up in the top-not perfectly flat like the others.

The value of these capacitors will be different, most likely they will be somewhere around-820 to 2200uF/25 V( or /10V sometimes)

You can replace them with same values but I would recommend the voltage rating to be higher(like 35V for an original 25V) for reliability purposes.

What happens is,these bulged top capacitors will cause a low and unfiltered DC voltage=main board will malfunction(the relay will keep clicking until the caps are holding enough charge to bring the voltage up over a threshold point).

You can buy these capacitors at any Fry's or Radioshack store or you can order them online at vendors like "mcmelectronics.com"(look for electrolytic capacitors).
After replacing these capacitor(capacitors) most likely the normal operation will be restored.

Note: There may be also some other causes for this symptom ,like a defective T con board ,or main board,but the bulged top capacitors are the most common cause for this issue.

If you don't know about TV repairers, take the TV to the nearest repairman to fix the fault for you. Also, note that TV stores a lot of current, so wait a while before opening the TV back cover.

I hope this helps.

Good luck.

power supply problem.

It may be in the safety shutdown mode due to fault in the circuits. Need to do some voltages checking.
If you are going to DIY and have proper tools and know safety precaution then please read on:

Please see my basic troubleshooting guide here:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide

http://s807.photobucket.com/home/budm/allalbums

http://en.wikipedia.org/wiki/Capacitor_plague

Parts: www.shopjimmy.com