Bush IDLCD32TV16HD Dead

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

wasn't plugged in Tom.

still can't find what I have done to lose my voltages.

cheers for the bonus point.

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

What is this device? Looks like a transformer of some kind. Has this written on it. 745-000-PQ2625H
LAE PQ2625 0720
I was measuring voltages on it with the black probe on the - of the big cap, i touched the red probe on this and it went boom, big spark and blew the fuse.

You can see the scorch marks, i have resoldered it because the solder was destroyed in the big flash.

Now i am too scared to probe anywhere for more voltages.

Pretty sure i didn't short it out with my probe.

Edit:

Just found this, and still dont know why it went boom.

[retiredcaps]

Re: Bush IDLCD32TV16HD Dead

I was measuring voltages on it with the black probe on the - of the big cap, i touched the red probe on this and it went boom, big spark and blew the fuse.

When you are probing on the hot side, you should always be wary because some voltage points may be as high as 400V DC. As slip of the probe can cause serious damage.

If you have/must measure high voltage, consider investing in aligator/smd clips so you can measure hands free.

You may also want to consider investing in a better multimeter as well if you want to pursue this as a hobby or get more serious about repairs.

PS. I do/did all of the above and wear safety glasses.

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

Looking at my probe it seems i did infact short it out. 2 Burn marks on my probe that allign perfectly with the shorted area.

How can i tell if this is a multi layer board?

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

When i apply a little pressure here i hear a brief buzz, just like i used to when i had voltages.

The connector arrowed was a pain to get out so i must of flexed the board too much and broke a solder joint somewhere.

Been over the whole board with more solder and its still not working?

This is doing my man tits in.

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

Great, another bang and now shorted.

Think i broke the bridge rectifier.

Lookin like a new power board.

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

Yep, deslodered the bridge rectifier and 2 of the 4 pins are 0 ohms both ways.

Its a d3sb60, can i use any BR or does it need to be exact.

[tom66]

Re: Bush IDLCD32TV16HD Dead

Any 600V, 4A device that fits will be fine.

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

My new power supply arrived today, and it's still doing the same thing? I get a blue led but no backlight.

[tom66]

Re: Bush IDLCD32TV16HD Dead

Do you get good +24V?

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

don't k now how to do that because the inverters are on the psu. I heard the inverter trannys are supplied with 400v.

[tom66]

Re: Bush IDLCD32TV16HD Dead

Ah. Right then. You could try Budm's CFL trick.
https://www.badcaps.net/forum/showthread.php?t=19987

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

Sorry for taking so long, Virgin are crap, internet was off most of yesterday.

I get no flash from the ccfls, all the bulbs are connected to long thin strips of circuit board so if one bulb died the others would light up. I think i have been sent a dud psu, he did say it came from a working tv with a smashed screen, he sells lots of parts.

The tv is working with the flash light trick, just no backlights. All the correct voltages are going to the main board.

I might try them 450v 10uf caps just in case. Its doing my head in.

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

Would the ccfl trick of budms work with this layout?

Here is a crap pic of my bulbs, but you get the idea.

It has around 10 bulbs in parallel, no bulbs are cracked and there is continuity from the connector to each bulb.
Also, them 2 450v 10uf caps, when testing voltage on them 1 of them starts at 190v then drops all the way to 130v when i probe it, but if i move the probe away for a couple of seconds and probe again it 190v and drops again? The other one starts at around 230v and drops just like cap number 1, then goes back to 230v when i more the probe, starts to drop again the second the probe touches it?

They act the same even when backlight connector is unplugged.

Main filter cap is around 400v.

[tom66]

Re: Bush IDLCD32TV16HD Dead

It should. It may cause the test CFL to arc over and burn out! As that arrangement sometimes uses close to 3000V.

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

it's working now.

the psu came without that 20 pin ic near the red led. luckily I love stripping components of dead things, looked in my box of tricks and found the ic. slotted it in and it booted straight up.

I did notice it missing but thought it was just to control the status led on the psu because the guy said it came from a panel damaged tv.

it came from a Polaroid tv maybe they don't need that ic.

so happy I like to keep seemingly useless stuff.

Thanks guys again.

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

pic of ic and tv on.

[tom66]

Re: Bush IDLCD32TV16HD Dead

Great. Heh, I think that is a little microprocessor. It checks the PSU is working OK and sequences the outputs. So it might be necessary for turning it on.

Nice fix!

[gilly1984]

Re: Bush IDLCD32TV16HD Dead

Back lights went off after half an hour last night but sound continued, so i switched it off and on and everything worked again? Stayed on fine til i went to bed, tv has been on for hours this morning with no problems?

Any ideas?

[tom66]

Re: Bush IDLCD32TV16HD Dead

If it gives more problems, I'd suspect cold joints or a loose connector.