Sharp aquos lc c4655u

[eagle00799]

Hi everyone, I'm hoping someone can give me some help on this. I picked up this tv with the green light blinking so after holdiing down the channel down and the volume up i now got it to display for 1-2 seconds and then black screen. The sound works and i can change channels and i can see the image on the screen. If i unplug then replug the 4 wire connector that runs from the power supply to the inverters the backlights will come on again for 2 seconds then off again and i can do that repeatedly but the lights just wont stay on. I have tryed tightening the inverter screws but no change. Does anyone have any ideas on which way to go on this? inverters? backlights?power supply?

[budm]

Re: Sharp aquos lc c4655u

There are printing close to the white connector with 4 wires attached to it on the inverter board, what does it say on the printings?

[eagle00799]

Re: Sharp aquos lc c4655u

1 sgnd
2 stb
3 ofl1
4 osl
5 err
6 reg
7 reg2
8 brt
9 ofl2

[tom66]

Re: Sharp aquos lc c4655u

What does ERR read when the set lights up then shuts down?

[eagle00799]

Re: Sharp aquos lc c4655u

The ERR reads 3.07v when lights are on and .415v when lights go off. When i plugged it in this morning to test the ERR the tv kept shutting off but i could turn it back on until it eventually started the green light flashing so i did the channel down and volume up reset and now the sound is on and stays on but the backlight still shut off after a second or two.

[eagle00799]

Re: Sharp aquos lc c4655u

Heres an update of what i done so far. i am able to get the screen to come on briefly(2 seconds)everytime i unplug and replug in the connector so by doing that i was able to see the k on the screen after holding in the input and vol- buttons and then i entered the service menu by pushing the vol- and channel- buttons. There was no lamp err but there was a monitor err cause of 6 so i reset that and then did an Industry Init. but none of this has changed anything but i did see in the service menu that the lamp hours were 19,*** hours and when i breifly get the screen on i notice what looks like maybe all the bulbs are not coming on, i can see lines.
I also checked the voltages and i get the same readings from the 4 wire connector that runs from the power supply to the inverters and the 4 wire connector going from power supply to main board and are labeled Inverter 1,2,3,4,5 with nothing in Inverter 3 hole so the readings are Inverter1=0 and this is the 1-SGND , inverter2=3.24v with lights off and slightly higher when lights on and this is 2-STB at the inverter, Inverter4=.415v w/lights off and 3.17 w/lights on and this is 5-ERR at the inverter, Inverter5=2.17v and this is 8-BRT at the inverter. Also on the power supply is a 3 wire connector going to the inverters and the Inverter12V reads 11.85, then SGND, Inverter60V reads 62.2V.
There is an 11 wire connector running from power supply to the main and the 13.5signal=12.89v, 13.5audio=12.81v there are 2 of these wires,then there are 3 that are not labeled at the power supply and they have no readings, the next 3 wires are not labeled at the power supply but have readings of 3.0v,3.04v,3.22v. The next wire is not labeled and has no reading and the last wire being BU5V=4.98.
There is a 4 wire connector going from power supply to t-conn board with 2 wire labeled PNL12v and these read 12.07v, and the other 2 being SGND.
Any thoughts on this? i'm wondering if the bulbs are just out of life?

[johnboy1313]

Re: Sharp aquos lc c4655u

There's only one way to find out for certain. Sounds like it's time to open the panel up and have a look. Take your time and be careful, and it should be a snap.

[eagle00799]

Re: Sharp aquos lc c4655u

Is there any place to get replacement lamps/bulbs at a reasonable cost or maybe this tv isnt worth fixing?

[eagle00799]

Re: Sharp aquos lc c4655u

Of course i want to make sure its not the inverters also. i have tightened the screws but no luck there.

[tom66]

Re: Sharp aquos lc c4655u

Yes, you can get bulbs for most sets and often bulbs from different sets will work as long as the length is about the same.

[cashkennedy]

Re: Sharp aquos lc c4655u

http://www.ccflwarehouse.com/ is a good place to get ccfl bulbs. Make sure you measure very accurately (thickness of the bulbs is hard to measure because of them having a 1mm clear glass shell often)

The bulbs will not come with the same conectors on the end so you will have to improvise like soldering the bulb to the socket, or trying to remove the old connectors and recrimping them to the new bulb.

You could also check ebay / local sellers for broken sets that might have the same bulbs.

[johnboy1313]

Re: Sharp aquos lc c4655u

I've had success getting used bulbs cheap from a guy that advertised to buy broken tvs locally on Craigslist. Like cashkennedy said, they had to be soldered in, but they're still going strong.

[eagle00799]

Re: Sharp aquos lc c4655u

Ok i took this thing apart to check the bulbs and it turns out that every other set of bulbs are out, 2 on,2 off,2 on,2 off,2 on,2 off,2 on,2 off,2 on,2 off.
So its safe to say that the bulbs are more than likely to be ok and it in the inverter? What do you guys make of this?

[budm]

Re: Sharp aquos lc c4655u

Are they all connected in parallel without any ballast caps for each lamps? Are they also socketed in place?

[eagle00799]

Re: Sharp aquos lc c4655u

Here are some pics of how they are connected, not sure what you mean by ballast caps and socketed in place so hope these pics help answer that.
Pic 1 is of the inverter side, pic 2 is the other side and pic 3 is the inverters.

[johnboy1313]

Re: Sharp aquos lc c4655u

If the bulbs are out like that, you're probably right that it's the inverters. You can swap the bulbs to confirm it.

[eagle00799]

Re: Sharp aquos lc c4655u

Well i really dont want to touch the bulbs cause they are so fragile and dont want to risk breaking one so tomorrow i will remove the inverters and clean the contacts maybe with some emery cloth and see what happens.

[cashkennedy]

Re: Sharp aquos lc c4655u

Odd, I cant figure out how the bulbs are connected on the side that doesn't have an inverter. You would expect pairs of 2 bulbs to be connected on that end
edit: looks like the end with just the metal sockets is on a beige circuit board, you would possibly have to pop out that circuit board to really see the traces and how the bulbs are paired off.

Although I agree its not bulbs the problem seems pretty bizzare for every other pair to be out, considering theres like 12 transformers in this set and the change of every other one going out is very unlikely... So I would assume the transformers are fine, but there might be separate fets / 24v traces on the inverter for every other transformer, and that may be why your problem only occurs on every other transformer / bulb pair.

[eagle00799]

Re: Sharp aquos lc c4655u

Well i cleaned the contacts of the inverter and still the same results, There are 10 transformers and 20 bulbs on this set.
Do you think i should get new inverters and give that a shot? Anyone else have an opinion on this issue?

[eagle00799]

Re: Sharp aquos lc c4655u

Update: I installed new inverters and the tv now works like it should. Thanks to the help i got from the very knowledgable people on this forum we have saved another one. Thanks guys!