So i thought it was no good

[donnieb2]

Got a new power supply today and tried it out but the same thing solid white screen.So I was thinking maybe the set is just no good until I thought about the flashlight test and trying to hook to a signal I know was working (cable) instead of the standard blue no signal screen. Did that and I heard sound then the flashlight test and yes the lcd is working.So everything's working fine but the backlight it's working in reverse.The minute you plug it in the wall the orange light come's on and the white screen ( lamp supposed to be off ) But when you hit the power button the Blue light come' s on but the lamp goes off and you need a flashlight to tell it's working.But I find it a relief that it still works but the lamp's are just screwed up.So im asking is there anyway to power the ccfl bulbs separate from the monitor maybe with a 12 volt power supply? So if i can get the ccfl working while the blue power light is on then Ill be good to go.Or if I can find some good lcd lamp mods .Anyway thanks for taking the time to read this.

[budm]

Re: So i thought it was no good

I cannot follow your explanation, make and model of the TV? Original problem was????
Old power supply board matches the new board?

[gilly1984]

Re: So i thought it was no good

So, when in standby the backlights are on, and when you switch the tv on the backlights are off?

Check the voltages on the bl-on. Should be on the wire from the psu to inverter.

Could this be a shorted mosfet? <<I think mosfets are switches? If i am wrong what are the switches?

[budm]

Re: So i thought it was no good

I sounds like the new power supply board uses difference BL_ON mode, it is still switching, just backward from what it should be, hence, the new board is the exact replacement?

[donnieb2]

Re: So i thought it was no good

I cannot follow your explanation, make and model of the TV? Original problem was????
Old power supply board matches the new board?

It's the polaroid tla-01911c original problem was no power until I got a new power supply and brought it back to life but its was working in reverse.So I sent it back got another and it's the same problem as before.Matching board all I know is the guy said it was a replacement psu for a tla-01911c.


So, when in standby the backlights are on, and when you switch the tv on the backlights are off? Yes exactly that's the problem im having it's working in reverse

Check the voltages on the bl-on. Should be on the wire from the psu to inverter.I have no way of checking out the voltages I don't have that kind of equipment

Could this be a shorted mosfet? <<I think mosfets are switches? If i am wrong what are the switches You lost me on that one yes im an idiot when it come's electronics


I sounds like the new power supply board uses difference BL_ON mode, it is still switching, just backward from what it should be, hence, the new board is the exact replacement? Im thinking this is most likely the answer


But im wondering is there a way to hook the backlights up separate and how many volt's do a ccfl take to power on I mean everything would be alright if I can just power the backlight without using the inverter board.Im just trying to make this tv last until I can get a new one.And i dont care if it look as long as im seeing a picture

Thank you gilly1984 and budm for helping with my question

[gilly1984]

Re: So i thought it was no good

Inverters use 24v dc then convert that to a couple of thousand volts ac so thats out of the question.

Get a cheap dmm and take some readings.

[budm]

Re: So i thought it was no good

Can I see the pictures of the board, both sides? Old board and new board.
19" TV probably uses 18~19VDC for the backlights inverter section.
To make it real cheap repair is to put a swtich on the BL_ON control line to turn it on and off.

[donnieb2]

Re: So i thought it was no good

Can I see the pictures of the board, both sides? Old board and new board.
19" TV probably uses 18~19VDC for the backlights inverter section.
To make it real cheap repair is to put a swtich on the BL_ON control line to turn it on and off.

Sorry i don't have a camera to take any pictures But I like that idea about trying to make a switch to control the backlight im willing to try it but how would I go about doing this? About the board it's this one http://www.shopjimmy.com/polaroid-86...wer-supply.htm I got it yesterday

[gilly1984]

Re: So i thought it was no good

You will most likely need a DMM cause if you put a switch on it you're going to want to know when you are feeding the bl-on with the correct voltage.

Go and get a cheapo multimeter, couple of $

[budm]

Re: So i thought it was no good

Yes, you will need meter, as you can see from the picture at the botttom right where the multi-pin connector is, top row pin number 3 from the right is the backlights on control pin. I need to konw what the DC voltage is when TV is on and when TV is off. You have soldering equipment and know how to solder?

[donnieb2]

Re: So i thought it was no good

Yes, you will need meter, as you can see from the picture at the botttom right where the multi-pin connector is, top row pin number 3 from the right is the backlights on control pin. I need to konw what the DC voltage is when TV is on and when TV is off. You have soldering equipment and know how to solder?

I think I know what you mean when u say multi pin connector you mean the piece that connect's both board's together. So the backlight controller is in there but im still gonna have to wait until I can get a meter. I have a soldering iron and some soder but my soldering skills isnt to great.But I got to run but once again thanks guy for the help.

[budm]

Re: So i thought it was no good

Yes, the connector that interfaces the two boards together.
What you should have on that pin 3 top row from the right as shown in the pictures (you can also see the labels of all the pins) when monitor is plug in but not turn on, it should be 0VDC, when monitor is on, it should be >3VDC.

[gilly1984]

Re: So i thought it was no good

Get some pics up and you may not have to mod it. Be better if it was working proper instead of

[donnieb2]

Re: So i thought it was no good

Look's like it's going to be a while before I get any money for a multimeter.But I was still curios about making a BL switch and how it would be done.Or if there was a way to just power the back light separate. I seen that done a lot with these do it yourself led backlight kit's running on a separate power-supply. I could go for that but I dont know much about powering ccfl I heard it could be done using a pc molex cable im wondering is it true and how would go about doing that.

[budm]

Re: So i thought it was no good

You havwe access the BL_ON control line (pin 3) as I mention and separate that from the main board, that line will then be connected to the switch which will have a pull up resistor to make the signal logic High and also position to ground for logic LOW so the control line will either be HIGH or LOW depends on the switch setting for turning the backlights inverter circuit on and off.

[donnieb2]

Re: So i thought it was no good

It's me again with something I Just find out while messing around with this tv. Yes I know its stupid but I took a flat head screw driver and start fiddling around with the connection pin's .And found I can control the backlight's turning them off and on by hold the screw driver a certain way .And yes when you press the power button everything back to normal like the good old day's. I even took a look at my hdmi input from the pc just to see my pc screen again I miss those day's and I even checked my cable input everything was fine. But who in their right mind going to hold a screw driver in place to watch tv Anyway just wondering would it safe to make I guess what you would call a jumper to make a permanent connectionIll just simply unplug it from the wall when not in use.Thanks for reading this

[gilly1984]

Re: So i thought it was no good

Show us some pics of your little "hack" in action.

[budm]

Re: So i thought it was no good

If you look at the connector, pin 4 from the right top row is the P_ON (power on pin) which also toggle HI-LO, it is next to the BL_ON pin 3, so it sounds like you are using P_ON pin to control two functions.

[donnieb2]

Re: So i thought it was no good

Hey guy's I want to say thanks for all the help and also to say I think I may have found a simple solution to my problem.Yes a hard drive jumper by having the bl -on and p-on as one using the jumper pin.Now what happens when I plug it in the wall. First the white screen again for like a split second then it goes out.Then when I press the power button white screen again for about split second then I see the Polaroid logo then the blue screen then the no signal flashing ahh just like normal yeah I had to check my hdmi again. So I did this a couple time to make sure it works and it seem to be ok using a jumper .But is it safe that's what I wanted to know before putting it back together. Haa a harddrive jumper and the dude a shop jimmy telling me I need another main board for like 60 bucks he may have just got anyway thanks again for you help guy's

[budm]

Re: So i thought it was no good

Great, So the board has a jumper setting to allow it to be used in different setup.