Polaroid 32in LCD FLU-3232 no power

[selldoor]

Re: Polaroid 32in LCD FLU-3232 no power

Hmm I thought the T meant time delay ie slow blow and thought he needed these
http://uk.farnell.com/multicomp/mst-...-5a/dp/1566097.

However looking at the state of the board perhaps an external fuse holder on leads would be the way to go? - or the Bulb?


LATE EDIT DEFINITELY NOT THIS ONE ITS ONLY .5 amp not 5Amp

[tom66]

Re: Polaroid 32in LCD FLU-3232 no power

Hmm I thought the T meant time delay ie slow blow and thought he needed these
http://uk.farnell.com/multicomp/mst-...-5a/dp/1566097.

However looking at the state of the board perhaps an external fuse holder on leads would be the way to go? - or the Bulb?

Good point, although that probably wouldn't fit...

This is a time delay type.

http://uk.farnell.com/littelfuse/032...-5a/dp/1596838

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

Oh I think I've removed the wrong thing. Is the fuse the long thin thing inside a plastic jacket that almost looks like a perpendicular resistor covered in gloop? In that case you had one of the pins right but I think the other one is below it not to the left. The thing I removed was the grey box next to it (I thought the fuse was inside it?)

Trying to find the second pin for it I snapped one side, but at least now I can test if it *was* working if I touch one pin to the remaining solder joint, and the other to the other side of the fuse I get 00.5 (same as touching the pins together)

If I touch it to the grey box I get 0L (same as touching nothing).

Just in case I'm still not sure what the fuse is, I've uploaded another photo. The grey box is next to the side of the fuse (?) that's still in place. http://i.imgur.com/e9FB2.jpg

Farnell seem to still have a minimum order of £20 for card payments annoyingly, so I might have to try ebay after all.

[tom66]

Re: Polaroid 32in LCD FLU-3232 no power

Are you sure about the minimum order £20 via card? For me it is £0.01; but I have made a few orders before...

The grey box is a capacitor (for filtering the interference produced by the rest of the power supply), no need to remove it.

What you have partially removed is the fuse.

Damn I hate the manufacturer for using a soldered in fuse.

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

I ordered a Raspberry Pi off them in the past but apart from that I've never used Farnell. I'll solder the capacitor back in when I get a fuse, but doesn't the fuse giving the same resistance as touching the probes mean that the fuse was working?

[tom66]

Re: Polaroid 32in LCD FLU-3232 no power

I ordered a Raspberry Pi off them in the past but apart from that I've never used Farnell. I'll solder the capacitor back in when I get a fuse, but doesn't the fuse giving the same resistance as touching the probes mean that the fuse was working?

Assuming you were probing across that component you half removed, then yes, 0.6 ohms is good for the fuse.

There might be another fault on the PSU.

[selldoor]

Re: Polaroid 32in LCD FLU-3232 no power

I thought the grey box was the fuse also - couldnt see the C1 designation. If its good is the fuse repairable?

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

The fuse isn't repairable I don't think. I pulled a leg completely out, so I'd need to desolder the leg, solder it into the fuse and then back onto the board. Possible, but I'd be too worried about it breaking again (for the sake of 15p).

Should the capacitor show 0L. resistance? Is it possible that's blown? Or is that expected until the capacitor receives enough charge to discharge (it's been a long time since I learnt how they work!). The plug coming onto the PSU is a little shoddy too, but given that's straight 240V I'm scared to test it.

[selldoor]

Re: Polaroid 32in LCD FLU-3232 no power

Id just leave the cap for now - that type dont often go wrong.
I think that the mains connector was one of the points I suggested you resolder. Maybe take off most of the solder and apply fresh. Do you have
a solder sucker or soldermop. What Watt is your iron?

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

You're right it is. I'm away for most of today so I can't check the board or the soldering iron, but I'll try it tonight and let you know I'll also try to temporarily repair that fuse just so I can see if it worked. The soldering iron and sucker work, but they were free years ago with a Real Robots magazine and the iron starts to smell after a while. Also, the tip doesn't get hot, just the side of it. Maybe I'll use a decent soldering iron to bring my Farnell order over £20

[selldoor]

Re: Polaroid 32in LCD FLU-3232 no power

Ok - IF you can see what you need at CPC they currently have a free postage if £10 spent online offer - BUT its only for a couple of days.

Next thing to check might be the bridge rectifier - I think I have marked it in pink on the attached. It should have 4 legs and it might be marked
with + ~ ~ -. the two middle ones being mains AC.
It is just an ohms test for open circuit. So Power off - Red probe
on plus black on adjacent~ record reading - reverse probes - record reading.
Then Black Probe on - Red Probe on adjacent~ record reading - reverse probes and record reading.

When fuse is fixed if Bridge is good next test will be the Mains cap 400v!
so practice first with it switched off/ unplugged - could still hold voltage if faulty so care is still needed - polarity must also be observed for that test meter on DC 600v.

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

Managed to break both sides of the fuse lol. Oh well, I'm not going to risk bypassing it.

I'll order one tonight and with any luck it'll arrive before Monday

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

Is this the right fuse? No minimum order here

[tom66]

Re: Polaroid 32in LCD FLU-3232 no power

Not really sufficient... Too small, will not interrupt the required current. Will just burst.

If you want I can put the order in for you for cost. I think Farnell will let me ship directly to you, I will need to check otherwise I could just use a stamp..

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

I feel so cheap but I'd definitely be up for that. I do need some stuff at some point just don't want to rush in and get the wrong things

Any chance you could order a few quid of solder as well? I'm down to the last 20cm of my free sample

PM me if you can ship to me and I'll give you my address?

[tom66]

Re: Polaroid 32in LCD FLU-3232 no power

I feel so cheap but I'd definitely be up for that. I do need some stuff at some point just don't want to rush in and get the wrong things

Any chance you could order a few quid of solder as well? I'm down to the last 20cm of my free sample

Don't worry - I've got about 1kg of the stuff - clear out from work place (leaded stuff that they aren't allowed to use any more.) I'll send you a bit.

PM me if you can ship to me and I'll give you my address?

I'll let you know shortly.

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

Okay I've got a fuse in place (badly, I still need yours - I've got a fuse holder that doesn't fit so it's sat a couple of inches above the board held in place by two wires from a mains wire).

I tested it when it was on, and I'm getting 230V AC at either side of the fuse. The bg capacitor is giving me 130V at one side and 150V at the other. I turned it off again and checked resistance of the bridge rectifier (400ohm) and got 0L for every possible combination. I took it out of the circuit and tested it again, same.

I take it this means I need a new one?

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

And if that's the case, are they all the same? This one has D3SB60705 on the side but Google is letting me down.

[tom66]

Re: Polaroid 32in LCD FLU-3232 no power

You need to test on the diode test mode. Usually a bridge rectifier fails shorted. Also, you should measure the capacitor voltage VDC across its positive and negative terminals, in standby you should get around 325V. (310 - 350V range.)

[DoctorWedgeworth]

Re: Polaroid 32in LCD FLU-3232 no power

On LED mode it gives:
Not touching anything: .018
When touching pins together: .006
Red on +, Black on ~: .022
Black on +, Red on ~: .007
Red on -, Black on ~: .009
Black on -, Red on ~: .016


Occasionally I got a negative reading but I was unable to replicate it afterwards. I'm now getting 0.012 with them not touching. why does a normal resistance test not work here?