Need Some Help

[burner6999]

I have a Nuvision NVU53FX that I am trying to trouble shoot. It has no power. It has no lights or anything on. When I plug it in with the back off the relay doesnt even click. I have 2 of the same models and switched the power supply with the other and it worked. Meaning this tv worked with the other tvs power supply. I have taken a picture of the board and Circled the relay that clicks when plugged in on the working tv. Could this relay be bad? Is there anything else between the incoming power and that relay. Besides the fuse that is. Is there a way to test the relay on board? Also the relay is a JZC-36F 005-HSLT
Can you give me a link to one that will work from digkey?

[PowerAmpFreak]

Re: Need Some Help

You could short the relay contacts temporary to check if there is a problem with the relay.
Probably the relay doesn't recieve a proper coil drive voltage, which you should confirm first.
Probably there is some kind of standby supply that needs to be up and running to supply the relay circuit and other auxilliary stuff. You have to find this supply and confirm that it's outputting proper voltages.

[selldoor]

Re: Need Some Help

Did you check the fuse and did you check for voltage at both ends of the fuse?
Do you get any voltage at the BIG Cap -With it plugged in and switched on, Meter on volts 600 DC put red lead on positive leg and black lead on negative leg - polarity is important CARE high voltage & do not touch any heatsinks.

[burner6999]

Re: Need Some Help

Thanks for the response guys. Now it is doing something different. Not sure what changed but now if I plug it in I get nothing, but if I let it sit for a couple minutes then unplug and plug back in relays click but wont turn on but the light on the front changes colors like it does when it comes on. Also when it does this the light doesnt flash like it normally does when it comes on. Normally the light goes from red to blue then blinks 4 times, then turns on. Then if I unplug and plug it back in again the relays click and then it turns on and will stay on. But if I turn it off and let it sit, it wont turn back on. The light on the front changes like it is coming on but it doesnt blink and the tv doesnt come on. Then if I unplug and plug it back in it will work like normal again. I think it is only the power supply cause it does the same thing in both tvs. But the working power supply makes both tvs function like normal. I am so confused. What could be causing this now?

[tom66]

Re: Need Some Help

Classic bad startup cap or bad main caps issue.

[selldoor]

Re: Need Some Help

Still do the test on the BIG cap - do it in each fault state.

[multimeter]

Re: Need Some Help

check these caps marked in red

[burner6999]

Re: Need Some Help

ok so I tested the caps. The main cap (Big one) gave me 400V. The other ones I marked the readings on the picture. The best I can tell the are all 50V caps

[multimeter]

Re: Need Some Help

ok so I tested the caps. The main cap (Big one) gave me 400V. The other ones I marked the readings on the picture. The best I can tell the are all 50V caps

what readings are these?,capacitance,voltage,esr?

[burner6999]

Re: Need Some Help

Voltage.

[multimeter]

Re: Need Some Help

you need to test them for esr,do you have a esr meter?

[burner6999]

Re: Need Some Help

No I do not.

[multimeter]

Re: Need Some Help

it does sound like you have a startup cap problem,but could be other things though,do you have a hot air gun/hairdrier?

[burner6999]

Re: Need Some Help

I have a hair dryer.

[multimeter]

Re: Need Some Help

put the power supply back in the tv,connect all the cables back up,make sure the psu is grounded by fixing it back with its screws,leave the back cover off,use the hair drier on the hot setting.switch the tv on at the mains and its standby,heat the circled caps up ,if these caps have gone high esr,the heat usually will lower the esr enough to get the cap working for a while,.if this dosent work,it still dosent mean that the caps are good and will need to be eliminated by further testing

[burner6999]

Re: Need Some Help

Ok I will let you know.

[multimeter]

Re: Need Some Help

i forgot to add,as you heat the caps,make sure you cycle the standby switch on the tv or the remote standby,as some tvs need it to turn on

[burner6999]

Re: Need Some Help

Ok I did that and now it is doing nothing again. I did notice that when it isnt working I get no power to the circled area. From the plugs I only get 5v and 3v Nothing on the 24v, 14, or 12v pins.

[budm]

Re: Need Some Help

You are getting the standby voltages OK, but to have the 24/12V power supply running, it needs to get PS_ON signal from the main board, you need look for the pin on the power supply or on the main board that is labeled with PS_ON, P_ON, etc.
Closed up pictures of the connectors will help.

[burner6999]

Re: Need Some Help

Having trouble with the up close picture but the only thing I saw on there was on/off pin. On it I have power but it keeps jumping from 3.5 to2.9v Back and forth. Edit: Got the pic. The ones circled have the connectors and the big one on the left has the on/off and goes to the main board.