TV sound no video DX L40 10A

[fatcat]

Re: TV sound no video DX L40 10A

Mosfets from top of board going down 6 mosfets.
First readings in m ohms are black lead on source, second are red on source.

S2 to D2

5.13------------11.82
5.32------------11.92

6.13------------11.81
6.35------------11.62

6.18------------11.84
6.44------------1148

11.17-----------14.07 This one's values rise to OL at times
9.77------------12.78

9.23------------9.13
8.29------------9.29

12.93-----------12.51
12.80-----------12.56

S1 to D1

5.56------------11.96
5.43------------11.98

5.87------------11.68
6.34------------11.72

6.58------------11.47
6.58------------11.67

9.77------------9.34
9.88------------9.30

9.20------------8.77
9.21------------9.09

9.04------------10.51
8.97------------10.62

[dick_barton]

Re: TV sound no video DX L40 10A

These readings were all Mohms ?

[budm]

Re: TV sound no video DX L40 10A

Ohm? K Ohm? M Ohm?

[fatcat]

Re: TV sound no video DX L40 10A

Yes, all readings are m ohms.

[fatcat]

Re: TV sound no video DX L40 10A

My meter has 2 m ohms ranges, .00 or 0.0.
The readings are 0.0 range with the meter on auto.

[dick_barton]

Re: TV sound no video DX L40 10A

Can you check the DC voltage at the connector CN101 and note the voltage at switch on and if it changes.
It's ENA (Enable) and ERROR_OUT that is of interest.

Pin1 to Pin 5 = VIN
Pin 6 to Pin 10 = GND
Pin 11 = ERROR_OUT
Pin 12 = ENA
Pin 13 = DIM
Pin 14 = EX-DIM

[fatcat]

Re: TV sound no video DX L40 10A

DCV Range is 0.00

pin 11 = 0.07 v
pin 12 = 4.09 v

Yes the voltage changes when starting up.

[fatcat]

Re: TV sound no video DX L40 10A

Sorry, sometimes pin 11 goes to 0.52. I don't understand why the readings vary.
Pin 12 is stable at 4.09.

[fatcat]

Re: TV sound no video DX L40 10A

EX-DIM and DIM are both around 2.90v.
pins 6-10 = 0.00v
pins 1-5 = 25.11v each

[fatcat]

Re: TV sound no video DX L40 10A

I'm leaning towards ordering an inverter board from China, 30 bucks with free shipping and is supposed take up to 15 days. It's not a Samsung board but is marketed as a direct fit replacement.
What do you think about these boards?

The other option is to open the screen to check the lamps first. What you you do?

[budm]

Re: TV sound no video DX L40 10A

I'm leaning towards ordering an inverter board from China, 30 bucks with free shipping and is supposed take up to 15 days. It's not a Samsung board but is marketed as a direct fit replacement.
What do you think about these boards?

The other option is to open the screen to check the lamps first. What you you do?

You have Samsung LCD panel and Samsung inverter board that goes with the panel so I am not so sure that there is substitute inverter board that is made by other companies beside Samsung.
You should request good clear picture of the board to verify.
http://www.shopjimmy.com/samsung-lj9...t-inverter.htm

[fatcat]

Re: TV sound no video DX L40 10A

I wasn't sure if I could post links but here it is:

https://www.ebay.com/itm/New-Inverte...-/282651185384

Doesn't look the same but is supposed to fit and work. The problem with shopjimmy is the shipping to Canada.

[budm]

Re: TV sound no video DX L40 10A

Original:
https://www.ebay.com/itm/Original-L4.../153042626894?

[fatcat]

Re: TV sound no video DX L40 10A

Thanks for the link.

[dick_barton]

Re: TV sound no video DX L40 10A

This is a bit of a puzzle. It appears that you have all the voltages necessary to bring up the backlights ie 24V & ENA however even though one section of the inverter board has obviously overheated none of the transformers or mosfets show any obvious faults according to the readings provided. Also your readings indicate that the Error_Out voltage does not change significantly.

In a darken room do the backlights flash briefly each time you power up or do you have to try multiple times (with a short break inbetween each attempt) before they flash?

[dick_barton]

Re: TV sound no video DX L40 10A

I've taken some resistance readings of the SEM2107 I have on my board. Power to the set off, of course. Black meter probe to the 24V ground pin at the connector and using red meter probe to take resistance readings. Meter set to auto range. [OC = no reading (OL on meter)]

[fatcat]

Re: TV sound no video DX L40 10A

In a darken room do the backlights flash briefly each time you power up or do you have to try multiple times (with a short break inbetween each attempt) before they flash?

I usually have to press power more that once to get the tv to power on after it has been off for a long time, but once it powers on the back lights come on and then shut down. After the tv has powered up once I can turn it off and on and each time the back lights come on and go off.

[fatcat]

Re: TV sound no video DX L40 10A

I've taken some resistance readings of the SEM2107 I have on my board. Power to the set off, of course. Black meter probe to the 24V ground pin at the connector and using red meter probe to take resistance readings. Meter set to auto range. [OC = no reading (OL on meter)]

Thanks for that. I'll check for these readings later on.

[dick_barton]

Re: TV sound no video DX L40 10A

I wondering if your SEM2107 IC is faulty but lets wait and see if there are any obvious resistance discrepancies.

[fatcat]

Re: TV sound no video DX L40 10A

I've taken some resistance readings of the SEM2107 I have on my board. Power to the set off, of course. Black meter probe to the 24V ground pin at the connector and using red meter probe to take resistance readings. Meter set to auto range. [OC = no reading (OL on meter)]

Checked with power unplugged.

PIN

1.-----17.20k
2.-----39.49m
3.-----111.8k
4.-----OL
5.-----110.1
6.-----7.14k
7.-----150.4k
8.-----51.2k
9.-----16.34m
10.----68.7k
11.----10.15k
12.----538k
13.----0.3 ohm
14.----OL
28.----19.19k
27.----0.4 ohm
26.----0.3 ohm
25.----36.36m
24.----23.84k
23.----108.1k
22.----0.812m
21.----OL
20.----0.3 ohm
19.----OL
18.----10.77k
17.----42.7k
16.----3.73m
15.----31.64m