Lg led projector burnt led driver

[Cryogen]

Quick edit: forgot to add the model

Lg PF1000u projector, please admin update the title. Thanks

Hi everyone

My projector died out a couple of weeks ago.

It's not techically dead, I can turn it on and I can hear it boot it properly, can turn it off as well, the fan boots but there was no image, no led turning on at all.

Yesterday I finally had the time (too busy at work) to disassemble it.

I opened it up and found out that the led drive part of the board had a short and had burned out. The part is the dlpa3000d from texas instruments.

It appears that pins 5 to 10 got a short and burned down, hence there is no power to the RGB leds.

Do you think it is the driver itself that went bad or there is another short on the board probably?

I have attached the dlpa3000d technical data sheet and some pictures of the led board.

Thanks

[Cryogen]

Re: Lg led projector burnt led driver

Pin 9 and 10 are low mosfet switch for led. I am starting to suspect that the short is in one or more of the 4 mosfets.

I will have to test them.

[Cryogen]

Re: Lg led projector burnt led driver

Woah this was so helpful. Thanks guys.
I mean, thanks me.

[dick_barton]

Re: Lg led projector burnt led driver

Have you removed the faulty IC and checked what damage may have been done to the board and tracks. The IC itself is pretty cheap around £10

[Cryogen]

Re: Lg led projector burnt led driver

Have you removed the faulty IC and checked what damage may have been done to the board and tracks. The IC itself is pretty cheap around £10

yes I bought the chip but when I removed the burnt one I found out than the tracks are gone.

I will have to check for someone who can repair burnt tracks. I don't have the tools to do so.

Any idea?

[dick_barton]

Re: Lg led projector burnt led driver

How bad is the damage. Post a sharp focused photo.

[Cryogen]

Re: Lg led projector burnt led driver

How bad is the damage. Post a sharp focused photo.

Hope they are clear, I can't find the macro in my phone.

[Diah]

Re: Lg led projector burnt led driver

the problem u have the area under the IC. need to take look under side which i think belong to pin 9
pins 5,8,10 easy to jumper them

[petehall347]

Re: Lg led projector burnt led driver

give it a good clean

[Cryogen]

Re: Lg led projector burnt led driver

the problem u have the area under the IC. need to take look under side which i think belong to pin 9
pins 5,8,10 easy to jumper them

You mean like the short is on the other side of the board?


Edit. Wait, you mean you think the short is on any of the 3 smd capacitors beneath the led drive? Yes I thought of doing a full recap anyway.

[Cryogen]

Re: Lg led projector burnt led driver

give it a good clean

I will. I have plenty of alcohol but couldn't find a small brush.

[Cryogen]

Re: Lg led projector burnt led driver

Here new pictures with board cleaned and other side of the led drive.

[petehall347]

Re: Lg led projector burnt led driver

getting this error for second 2 pics ...Invalid Attachment specified. If you followed a valid link, please notify the administrator

[Cryogen]

Re: Lg led projector burnt led driver

getting this error for second 2 pics ...Invalid Attachment specified. If you followed a valid link, please notify the administrator

Sorry pete I had to edit and reupload 20000 times cause I am using my wife's windows and am used to linux distros. I couldn't figure out how to save a rotated picture (I took the picture of the cleaned led drive upside down.

Should be fine now.

[Cryogen]

Re: Lg led projector burnt led driver

the problem u have the area under the IC. need to take look under side which i think belong to pin 9
pins 5,8,10 easy to jumper them

Pin 9 is probably on c504 on the back of the board?

[Diah]

Re: Lg led projector burnt led driver

Pin 9 is probably on c504 on the back of the board?

i think so too, but before you go further.. apply 12 VDC to the LEDs see if they come on and there no one shorted or open.

[Cryogen]

Re: Lg led projector burnt led driver

i think so too, but before you go further.. apply 12 VDC to the LEDs see if they come on and there no one shorted or open.

How did you figure out that the leds are 12v?

[Diah]

Re: Lg led projector burnt led driver

its standard for projector till 100 LUM

[Diah]

Re: Lg led projector burnt led driver

here LEDs function on currents level... you are going to use 12 V with low currents.

[Cryogen]

Re: Lg led projector burnt led driver

here LEDs function on currents level... you are going to use 12 V with low currents.

I was going to apply 5v on the led drive board and see if something overheats.

I need to know if pin 9 is the c504 thought.

I don't wanna jumper and then short the chip again.

I only have a 12v 3A power supply, that doesn't look like low currents.