Barco LCN-42 No Power

[Jasgriff]

Got hold of a new Monitor to play with!

Its come from a TV studio. They tried another power supply in it to get it going and it wouldn't so they decided to bin it. The nice chap I bought it off said that they don't really try hard to fix them its quicker just to put up a new one.

I have found the company that make then and the model is listed here...

http://www.barco.com/en/product/1821

It looks like they are a really good brand the quality feels amazing.

Has anybody ever delt with one of these? if do you you possibly have access to the service guide for it?

I have attached some pics.

[Scenic]

Re: Barco LCN-42 No Power

So.. what's the problem with it? lol

I already see a bunch of bulging caps on the board above the amplifier (?) heatsinks and a SMD fuse (with golden contacts!?) on the same board.

Can't really tell what that board is. The unconnected spaghetti all over the place don't really help either lol

[Jasgriff]

Re: Barco LCN-42 No Power

Im still taking it apart. Just took some pictures as it is so that I know what's going where.

I can see some bulging caps on the component input board.

Apparently they have tried another PSU in it already and that didn't work. I am going to take some more stuff off it then I will get some more pics.

You heard of this make before?

[Jasgriff]

Re: Barco LCN-42 No Power

Noooooooo

Blown Fuse! fallen at the first hurdle!

[Jasgriff]

Re: Barco LCN-42 No Power

Thought I would strip the Power Supply down a little to see what's going on.

Glad I did. Looks like a couple of caps have had it.

Also looks like there is a resistor burnt out.

Is it thermal paste that is used between the metal heat sinks?

[Jasgriff]

Re: Barco LCN-42 No Power

Here is underneath the board looks like more damage!

There looks to be a blown copper strip just above J34.

J34 also looks to be damaged. I will measure it to see if it is blown.

[retiredcaps]

Re: Barco LCN-42 No Power

Also looks like there is a resistor burnt out.

All I can see with 90% certainty is red black silver. I don't know about the last 2.

[Jasgriff]

Re: Barco LCN-42 No Power

Safe to say its well and truely gone though? Do you know what wattage it might be it looks massive.

[retiredcaps]

Re: Barco LCN-42 No Power

Looks like a couple of caps have had it.

In the motherboard and ATX PS sections of this forum, a lot of people say that OST branded caps can fail without bloating. I see some OST caps on your board.

[retiredcaps]

Re: Barco LCN-42 No Power

Safe to say its well and truely gone though? Do you know what wattage it might be it looks massive.

Try and measure the resistor out of circuit first to see if the first digit is a "2" for the "red band" on your Fluke 175. It might even show up as 19??? or some close variation.

I'm not the greatest at spatial awareness so I'll pass on the guessing. However, it looks like you have a lot of room around it so if you guess really high for wattage, then it will fit and you have a safety margin.

[retiredcaps]

Re: Barco LCN-42 No Power

Blown Fuse!

Whenever I see a blown fuse, I always check the bridge rectifier and power mosfet to see if they are shorted.

[Jasgriff]

Re: Barco LCN-42 No Power

I am sure that if I can see 2 failed caps then the others will more than likely be in poor condition.

I have fixed the SMD Jumper so now I am thinking replace the Fuse the Resistor and patch the broken track then give it a try?

Could that resistor blowing be responsible for the board damage?

Does the Jumper repair look good enough?

[Jasgriff]

Re: Barco LCN-42 No Power

Whenever I see a blown fuse, I always check the bridge rectifier and power mosfet to see if they are shorted.

I will Check the Rectifier and Mosfet now.

Here is a proper picture of the blown resistor it is showing as 'OL' so its definitely gone.

[retiredcaps]

Re: Barco LCN-42 No Power

if do you you possibly have access to the service guide for it?

How good are you at guessing file names?

I found

http://www.fspgroupusa.com/fsp4173m01/p/769.html





but neither show a schematic of the power supply.

[retiredcaps]

Re: Barco LCN-42 No Power

Does the Jumper repair look good enough?

See if it reads close to 0.0 Ohms. If yes, then it is okay.

edit: It is odd that J33 shows 000 and J34 shows just 0.

[retiredcaps]

Re: Barco LCN-42 No Power

I will Check the Rectifier and Mosfet now.

Maybe hookup a light bulb in series after replacing all the components since the fuse is blown?

http://www.repairfaq.org/samnew/tvfaq/tvtslbt.htm

[Jasgriff]

Re: Barco LCN-42 No Power

See if it reads close to 0.0 Ohms. If yes, then it is okay.

edit: It is odd that J33 shows 000 and J34 shows just 0.

It shows 000 as I store that off another board and replaced the blown one.

It reads close to 0 OHMS and I have traced it back to the nearest components each side and it still shows as close to 0 OHMS.

See I did such a good job you couldn't tell it was re soldered lol

[Jasgriff]

Re: Barco LCN-42 No Power

Does Red Black Silver Brown Green look about right for that resistor?

[retiredcaps]

Re: Barco LCN-42 No Power

Does Red Black Silver Brown Green look about right for that resistor?

With the above, according to the URL below, it is invalid.

http://www.hobby-hour.com/electronic...calculator.php

The silver might be gray? It is the 3rd and 4th band I'm unsure of. Initially I thought the 3rd band was silver and it still looks more silver than gray to me. However, I see the 3rd band can ONLY be gray due to it being a 5 band resistor.

That would make it 2.08k ohm 0.5% resistor if the 4th band is brown.

Maybe post another pic showing it rotated 180 degrees and try cleaning the resistor up with some isopropyl alcohol?

[Jasgriff]

Re: Barco LCN-42 No Power

The middle band cant be silver according to this website.

http://www.diyalarmforum.com/5-band-resistor-calc/

I have attached a better pic.