Polaroid 3211-tlxb

[junktv]

So this 3211-tlxb has a worsening problem. I'll turn it on and after it comes on it makes a pop sound in the speakers and turns back off. The red stand by light is on and turns to blue when it powers up but back to red when it shuts down.

I was hoping it had the same board as my Element 3211b since I had the two caps but it doesn't. All the caps look fine to me.

The place I circled had 2 HEC ZD 1000uf 10v caps. Any ideas?

[junktv]

Re: Polaroid 3211-tlxb

Going to buy a new tv anyway but would like to get this one going. Does this even seem like a problem that would be in the power supply or something in the main board?

Tv off is
5v is 5.12v
12v is 0v
24 is 0v

Tv on is
5v is 5v
12v is 11.7v
24vis 23.8v

[CapLeaker]

Re: Polaroid 3211-tlxb

easy. You are getting correct voltages from the PSU. To figure out what happens (I say it is the main board's fault), turn the TV on and let it run until it shuts down. I bet that the PSon voltage from the main board to the PSU is gone, and thus the PSU turns effectively the TV off.

[junktv]

Re: Polaroid 3211-tlxb

I guess PSon is "power supply on"? Would that be a 5v to the main board? I guess it should drop before it shuts off?

It's actually staying on now so I'm leaving it on for the peace and quiet. I did notice slight fluctuation in the 12v last time I powered it up. It dropped to 11.5v then back up to 11.7.

[CapLeaker]

Re: Polaroid 3211-tlxb

Take a measure of PSon when the TV is working correctly and take another measure when the TV turns off and compare. When the TV turns off, PSon voltage drops either too low for the PSU to stay on or zero.

[junktv]

Re: Polaroid 3211-tlxb

Ok none are labeled PSon but I tested the 5vsb and when it turns off it drops down to 1.4v for a second or 2 then comes back to 5+v. When it drops it is a split second after the backlight goes out.

[budm]

Re: Polaroid 3211-tlxb

Stb = ps-on
<1VDC = OFF, >2VDC = ON

[CapLeaker]

Re: Polaroid 3211-tlxb

5vsb is your STBY voltage, that should be always there and it shouldn't drop to 1.4V either. So, I think you should force the PSU and the backlight on and disconnect the main board. Take two 1k ohm resistors and jump 5vsb to PSON and from 5vsb to BLon (backlight). All power rails should be up and the backlight on.

[junktv]

Re: Polaroid 3211-tlxb

Thanks I had no clue where PSon is. When testing the stb it drops from 4.8v when on down to .06 but only drops a split second after the speaker pop and back light goes out.

As far as jumping I dont have any resistors unless i can dig one out of something else that had died or been scrapped.

[CapLeaker]

Re: Polaroid 3211-tlxb

How long does it take to get the speaker pop? Feel around on the main board, maybe something gets hot?
I am pretty sure the problem is on your main board. Just would be nice to really make sure and see if the PSU works correctly without having a hiccup.

[junktv]

Re: Polaroid 3211-tlxb

Kinda depends. some times it will stay on other a couple seconds or minutes. Not feeling anything warm or hot. Any other way to check?
.

[junktv]

Re: Polaroid 3211-tlxb

Would these work? http://www.radioshack.com/1k-ohm-1-4...k/2711321.html

[CapLeaker]

Re: Polaroid 3211-tlxb

that would be fine

[junktv]

Re: Polaroid 3211-tlxb

Ok they didn't have the ones I linked so got these. http://www.radioshack.com/1k-ohm-1-2...5/2711118.html

So you want me to unplug the main board then jump from 5vsb to stb on the power supply and also 5vsb to BLon which is what pin?

Am I just seeing if it kicks off this way or should I be measuring?

[budm]

Re: Polaroid 3211-tlxb

The BL-ON (invr-on) signal is NOT routed through the power supply board connector in this TV, the BL-ON (INVR-ON) pin will be right at the Inverter board connector.
That is why we always ask for the pictures of the whole backside of the T so we can see how all the boards are connected together. Polaroid is one of those bad design and hard to get to some of the boards.

[junktv]

Re: Polaroid 3211-tlxb

This shares the same body as my element and yes it is a pain to get to the back light boards. Sounds like that will be needed. Here is what is easy to get to.

[budm]

Re: Polaroid 3211-tlxb

Yep, I hate their design, there is big connector on the main board (bottom left of the board, 50 pin connector) that goes to the inverter board.

[junktv]

Re: Polaroid 3211-tlxb

I don't actually see a connector on the bottom of the main other than for inputs. I guess I'll yank it apart and update.

[budm]

Re: Polaroid 3211-tlxb

When you pull that whole assembly out, you will see the connector underneath.

[junktv]

Re: Polaroid 3211-tlxb

OK got it apart.