IQ LED-1903 green light, no video,no audio

[rippergr]

Hello
I have a tv IQ LED-1903 when I first plug it to power I turn it on the light indicator from red goes green but I have no video or audio and then I can't even turn it off.
I changed all the caps because at the beggining it did the same problem but after 10-15 minutes it was working.
I thing maybe it is a power regulator but I don't know much about them.
I measure 4 regulators

u5 BM1117-33 1116DYT
5,11V
3,31V
0V

u2 BM1117-33 1116DYT
5,13V
3,30V
0V

u1 1084 3.3 1048TQ
5.11V
0V
3,29V

u13 78D05L EAoFTA
5V
12.22V
0V

[budm]

Re: IQ LED-1903 green light, no video,no audio

Hello
I have a tv IQ LED-1903 when I first plug it to power I turn it on the light indicator from red goes green but I have no video or audio and then I can't even turn it off.
I changed all the caps because at the beggining it did the same problem but after 10-15 minutes it was working.
I thing maybe it is a power regulator but I don't know much about them.
I measure 4 regulators

u5 BM1117-33 1116DYT
5,11V
3,31V
0V

u2 BM1117-33 1116DYT
5,13V
3,30V
0V

u1 1084 3.3 1048TQ
5.11V
0V
3,29V

u13 78D05L EAoFTA
5V
12.22V
0V

Those voltage readings are correct.
How about showing the pictures so we can clearly see all the boards?

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

You mean to take more close pictures of the board?

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

There is not much information on this set maybe just for Greek market?
so you will need to provide more

Is it a one board machine with a mains adapter? If so picture one of the whole of the rear of the set.

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

I didn't thought that this could be loacl market tv.
Ok the TV has an external power adaptor 12V (which I already changed it to test it)
and 2 boards (and another 2 small that are the buttons on the back of the TV and the IR)
If you need more closeup photos of a board please tell me.

PS.: I noticed that the TV power down (red light indicator ) every 30-35 seconds and then it turns back on and makes a sort sound on speaker

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

OK - you need to improve your picture presentation - they are very difficult to look at when you are lookng at lots of pictures on lots of threads so the inclination is to look at a different thread

I have turned some of them to make it easier on the eye.

In my pic3 top right hand corner there is a pad area for a fuse F110
does it look like there has ever been anything on there? has it been knocked off?

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

There is still a fuse there but it is a flat green one. the F110 is on the fuse.
I measure it and it is ok

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

Hahhah - thought it was the board number - oh well - a missing fuse would have been too easy!
So for completeness what voltage do you get each side of that fuse with respect to ground.
When the set is switching on/off can you monitor the voltage at the socket from the adapter.
Does it still restart with (1) the plug with all red wires out of the socket on the led driver?board (what is the part number of the U1 on there)
(2) the plug with with the 4 red wires and blue and white.. (3) with both unplugged.
With it all together what voltage on each pin on the white socket on the LED driver board - can you list
Led Driver Board Connector
Pin 1 12v 11.99
Pin 2 12v 12.01
Pin 3 BL 1.7v and so on.

Do they fluctuate with the on/off cycle.

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

I have 5.05V on each side of F110.
I tried unplugging red wire plug, white plug and both. It still does the same.
Part number of U1 is me15n10-g
for the measurements.
pin 1 12V 12,29V
pin 2 12V 12,28V
pin 3 BL_ON 0,04V
pin4 BL_ADJ 4,80V
pin5 & 6 GND 0V

when the tv turn off the BL_ADJ goes from 4,80 to 1,9V all other remain with the same voltage

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

OK I dont think U1 is a mosfet - I mean the 20odd leg component
Encouraging to see voltages - and the 12v says while it is switching on and off- yes.
Problem seems to be with the BLON so we need a really good picture of the area on the main (BIG) board
where the grey wire plugs in - Un plug it first so the socket label is clear as well.
Include the voltage regulator in the picture.

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

Sorry for the mistake. you are right the u1 is not a mosfet the part number is
MPS1022
MP3389EF
A488114.8

I am attaching a photo (I hope I took the right photo because I didn't understood very well which plug you mean)

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

Yes that is better it is one of these
http://html.alldatasheet.com/html-pd.../MP3389EF.html
May have to come back to that later.

Picture is good thanks - but I cannot follow where the BLON pin goes.
Can you see and draw it on the picture?.

Also the other socket we have not yet touched with mant different colour wires
is that Audio to the headphone and speakers?

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

If you mean the BL_ON from the small board to the big board is the one I draw on the photo.
The socket that has the different colour wires goes to the panel that has the buttons behind the TV (power on, channel,volume etc.)

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

Yes that is the pin - sort of guessed that but where does it go after that.
Try tracing it with your meter on ohms200 - no power to the board- perhaps try to the row of pads on the socket that isnt there cn5 or to the set below cn6 where it labelled blon as well.

Looking at that last picture just above the red socker is a small 3 leg transistor
compared to others across to the left it looks odd - is it just dust or flux on the leg nearest the socket and the leg on the right doesnt look good either?
Just say if you dont know what I mean and I will do a picture

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

I try to follow the BL_ON pin but there is no visible trace to follow. Can you advice me to trace it otherwise?
As for the transistor it seems ok. Can I measure it to test it?

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

Ok as I said - ohms test is a way to trace. NO power to board meter on ohms 200 black probe on BLON PIN use red probe to test to 1 then 2 then 3.
On 4 you will have to test to the solder joints aon the back of the board.
then 5 test to each leg - what is the part number on 5.

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

ok now I've got it. Ive attached a picture from the pins on the bootom of the board.

pin 1 = 01,4
pin 2 = 01,4
pin 3 = infinitive

cap 4 = infinitive on both legs

transistor 5 part number AE1050 250329P E(uknown character)4242
It's not very clear the part number
in all legs it shows infinitive except the second from the left bottom which shos 01,0

Some pins shows a resistance for a while and then goes to infinitive. and in pin 1 & 2 sometimes it shows some weird readings 01,0 - 80,0

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

Should have asked - what does your meter show when you touch the probes together

[rippergr]

Re: IQ LED-1903 green light, no video,no audio

00,3 - 00,5

[selldoor]

Re: IQ LED-1903 green light, no video,no audio

ok didnt expect that from1 2 &3 I cant decipher that number into anything meaningful.
Try 1) rubbing chalk on and see if it reveals anything
2) cleaning gently with isopropanol