RCA black screen

[blake67]

OK I have RCA 42LA45RQ hdtv powers on, can switch inputs, volume up and down however its goes black also the screen is blue when first turns on then it says no video input(flying on screen_didnt have anything to plug into at the time) I can see the backlights coming as I have the back cover off, now from what I seen on line it more and likely the main power board( its also hold the inverter on that board too. So am I right to assume its the main power as I do notice a cap is slight discolored from the same one sitting next to it, there are only two boards in the unit main one with inputs and cpu etc and the power board. I sent a pic of the new one Im getting, if you look and right side by transformer there are 4 cap the two blues ones on top next to transformer the bottom of those two is discolored and that white connector goes too inverter board. as I stated Im hoping this is the problem.

[Caleb]

Re: RCA black screen

Do the backlights stay on? or are they out when the screen goes black? Some sets go black very shortly after they detect no signal. Can we get a picture of the whole back of the tv open?

[blake67]

Re: RCA black screen

they go out after the little no signal icon shows up, if Im correct this tv was hooked up to a source and the same thing happen, later today I'll hook up hdmi(directv) to see what happens, its 7am my time so too damm early lol

[blake67]

Re: RCA black screen

here are the photos
if you look at the first one you can see the discolored cap next to transformer. Being I can select inputs and control volume and menu, I don't think it's the main board.

[attainteddragon]

Re: RCA black screen

i would change out those ceramic caps to start with and check your backlight transformers while your there!

[tom66]

Re: RCA black screen

I agree, that cap could be causing the problem. It might only be that cap but a good idea to replace all of the blue disc ones on the power board and balancer board (the white board with the other blue disc caps on it.)

[blake67]

Re: RCA black screen

OK I plugged in my directv I get a picture and sound, inputs and menu show up. screen goes black and theirs still sound on. As I stated above I do believe it's the main power unit.

[blake67]

Re: RCA black screen

i would change out those ceramic caps to start with and check your backlight transformers while your there!

how do I check that out. I do have a digital multimeter but what I don't have is a soldering iron etc. Also looking at the inverter its seems fine and all the backlights are working.

[tom66]

Re: RCA black screen

The backlight typically has a 2~4 second timer, during which time it will ignore any problems. If it detects a fault it will shut down atrfter this timer expires. So you should be seeing the backlights lit for only a few seconds, or are they staying on indefinitely?

[blake67]

Re: RCA black screen

The backlight typically has a 2~4 second timer, during which time it will ignore any problems. If it detects a fault it will shut down atrfter this timer expires. So you should be seeing the backlights lit for only a few seconds, or are they staying on indefinitely?

It stays on for maybe 30 seconds to a minute or more but still goes dark

[tom66]

Re: RCA black screen

OK, but the backlight is definitely going out? You tried plugging a source into it with a picture to make sure it's not just an aggressive energy saver? Some Vizios are known to have 5 second timers on some inputs.

[blake67]

Re: RCA black screen

OK, but the backlight is definitely going out? You tried plugging a source into it with a picture to make sure it's not just an aggressive energy saver? Some Vizios are known to have 5 second timers on some inputs.

yes I plug in my directv hdmi cable and it comes on like I said for 30 seconds or more then the backlight shuts off.

its seems this is a commom problem per this website
http://www.coppelltvrepair.com/p/469...ng-off-problem

which if it is the discolored or blown cap on board I can get one a digikey since I live where the warehouse and its only 46 cents USD and I can borrow a soldering iron etc
All the other blue caps look fine even on the balance board etc

[tom66]

Re: RCA black screen

Well, it is handy to be that close to DigiKey, do they have a trade counter?
While you can probably get away with replacing just that cap it would be good to replace -at least- the four on the power board if not all the others on the balancer board.

[blake67]

Re: RCA black screen

Well, it is handy to be that close to DigiKey, do they have a trade counter?
While you can probably get away with replacing just that cap it would be good to replace -at least- the four on the power board if not all the others on the balancer board.

not sure about trade counter, Im assuming that all the for caps on board are same 15pf 6Kv. IF not let me know

[tom66]

Re: RCA black screen

They should be marked.

[blake67]

Re: RCA black screen

They should be marked.

no markings on either side of caps

[tom66]

Re: RCA black screen

Are you sure? Typically it's in very faint grey print.

[blake67]

Re: RCA black screen

Are you sure? Typically it's in very faint grey print.

dont have a magniferier but I think your right I have bad eyesight

[blake67]

Re: RCA black screen

well I just order a new power supply for 42 bucks a week ago, got it in and all is well, have picture and sound and no problems so far.......