Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

[JDC]

Short question: What are the circled components in the close up pics and how do I test them?

Long question:

Hello all. I've done what I can in searching Google, Google Images, and this forum in finding these answers myself. Quite frankly, my eyes are starting to hurt. Thanks to this forum, I was able to save a ViZIO VP50 from the landfill. I'm getting into this hobby more for the green side of it; I'd rather try to fix it than have it pollute the earth.

I have an inverter board for an RCA TV. L40FHD41YX9 ( part #INV40N14B) that isn't working as you can tell from the backside of the board in the pics. I'll be ordering a new one soon. I'd like to take this time to learn *why* it isn't working.

The meters shown are a Fluke 70 III Multimeter and a MESR-100 ESR Meter.

I'm looking for someone to identify the numbered parts in the close up and pic and tell me how I can test those components. I know the black/brown rectangles are transformers but how do I test those?

Any tips on how to identify parts in the future would be greatly appreciated. Thanks!

[SteveNielsen]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

It looks like a solder blob short on the 330uf cap I've circled in yellow.

I can't tell you what the parts are (can read no markings on them) except the white 4-pin blocks are probably opto-couplers.

[JDC]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

Thanks, Steve. I should reiterate that I'm not looking to repair this board but to identify and test the components as a learning exercise. I don't want anyone to waste any time troubleshooting.

Again, thanks!

[Ltank]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

Capacitor 330uf or 330micro farads cap rated 35vdc. That is a name brand cap. use your cap checker to see if it has a low ESR. The other multi leg devices are IC chips. Google the numbers on them to identify them, The larger parts are transformers. The white items I could not read the silk screen on the board.

[JDC]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

Capacitor 330uf or 330micro farads cap rated 35vdc. That is a name brand cap. use your cap checker to see if it has a low ESR. The other multi leg devices are IC chips. Google the numbers on them to identify them, The larger parts are transformers. The white items I could not read the silk screen on the board.

Any idea how to check if an IC is good or not?

[newtothis]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

You need to find the pinouts for them

[newtothis]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

It looks like a solder blob short on the 330uf cap I've circled in yellow.

I can't tell you what the parts are (can read no markings on them) except the white 4-pin blocks are probably opto-couplers.

That's just flux BTW

[JDC]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

You need to find the pinouts for them

So ICs don't follow a standard pinout?

[SteveNielsen]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

Not really, there are two many different types. You'd need to know the part # and look up a spec sheet for it for the pinout. Then depending on what it is you may or may not be able to test some parts of it. For example if it is multiple FETs in one package you can test each FET at the pins, but if it's a complex chip there's no way to test it without a specific tester set up for that specific chip, which may or may not exist. That's one of the caveats of integrated circuits, you can't test the parts built into them because you can't remove or isolate them from the rest of the circuitry in the chip. You can check for correct voltages on pins but there again you need to know what the chip is to know what the voltages should be.

[SteveNielsen]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

Mistake: "there are two many different types" should read "there are too many different types."

The white blocks are undoubtedly opto-couplers and you can test them by applying and removing 5v across the input pins and reading the resistance changes at the output pins. My guess is that the input pins are at the bottom of the opto-couplers from your pictures.

If you can get better pics of the other chips so we can read the markings on them we might be able to figure out what they are.

[ReeceyBurger123]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

These inverters are prone to blowing the fets little 8 pin chips going up the whole board, youve messed it up as well because youve removed the black bulb connectors so you now have to open the panel to reattach it. Normally I dont bother replacing the fets on these and just replace the whole inverter its alot easier to do as normally a bad smd resistor or cap is what blows the fets. The fets are just before the transformers they switch the high current for the transformers I bet that at least 4 of them test open.

[kc8adu]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

those are jumpers.

Mistake: "there are two many different types" should read "there are too many different types."

The white blocks are undoubtedly opto-couplers and you can test them by applying and removing 5v across the input pins and reading the resistance changes at the output pins. My guess is that the input pins are at the bottom of the opto-couplers from your pictures.

If you can get better pics of the other chips so we can read the markings on them we might be able to figure out what they are.

[JDC]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

If you can get better pics of the other chips so we can read the markings on them we might be able to figure out what they are.

Working on that. I'm sure once I get the numbers I could find it myself. I just didn't know if there was an end-all-be-all method to test the ICs (like testing fuses or a AAA battery, for example).

[JDC]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

These inverters are prone to blowing the fets little 8 pin chips going up the whole board, youve messed it up as well because youve removed the black bulb connectors so you now have to open the panel to reattach it. Normally I dont bother replacing the fets on these and just replace the whole inverter its alot easier to do as normally a bad smd resistor or cap is what blows the fets. The fets are just before the transformers they switch the high current for the transformers I bet that at least 4 of them test open.

I'm not understanding what a fet is or how I messed up anything. The new board is going to pretty much drop in place according to a ShopJimmy vid I saw recently (link not handy).

[ReeceyBurger123]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

I'm not understanding what a fet is or how I messed up anything. The new board is going to pretty much drop in place according to a ShopJimmy vid I saw recently (link not handy).

You see the black bar on the end of the inverter that attaches to the ccfl bulbs in th panel and is not supposed to be removed you need to open the panel to get the bulb connectors back into the black strip if not the screen still wont light up.

[JDC]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

You see the black bar on the end of the inverter that attaches to the ccfl bulbs in th panel and is not supposed to be removed you need to open the panel to get the bulb connectors back into the black strip if not the screen still wont light up.

Yikes, you're right. I should have left that black strip in. I thought it was all one piece.

Here's the vid I was referring to. Maybe it'll help someone:

https://www.youtube.com/watch?v=72kGU6SetpM

[ReeceyBurger123]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

Yikes, you're right. I should have left that black strip in. I thought it was all one piece.

Here's the vid I was referring to. Maybe it'll help someone:

https://www.youtube.com/watch?v=72kGU6SetpM

Yeah dont worry did the same thing unfortunatley you are going to have to take the whole panel apart to be able to get the ccfl electrodes back in he connector strip. You ust be very careful when taking the lcd display out and keep it flat do not boe it, also be very carful when installing the ccfl connectors as you don't want to break the lamps.

[JDC]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

Yeah dont worry did the same thing unfortunatley you are going to have to take the whole panel apart to be able to get the ccfl electrodes back in he connector strip. You ust be very careful when taking the lcd display out and keep it flat do not boe it, also be very carful when installing the ccfl connectors as you don't want to break the lamps.

Just got done doing just that. You wanna talk about 15 minutes of removing screws and chassis followed by 30 seconds of pure agony, lol. Never did that before.

[JDC]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

Alright, pulled one of the ICs off the board. I couldn't get a good picture so I wrote everything down. It looks like this
_________
|A 4614|
|BV9X15 |
_________

The "A" looks more like a slanted anarchy symbol.

[ReeceyBurger123]

Re: Here's Something Different: I Know It's Broke So Please Help Me Learn Why!

You get the bulb connectors back in ok ?
The Ics that tend to blow according to my notes are part number 4614 bv9x15 those tend to short and blow up all the zero ohm jumpers at the top of the boards which is where all the blackening is.