Samsung LN32c450E1D troubleshooting

[airshac]

I know these tvs are notorious for bad caps but I have opened it up and all the caps look normal. When the tv is plugged in there is nothing. No lights, no clicking sound. When I touch the power button on the front nothing happens. Any ideas or experience with this?

Thanks!

[johnboy1313]

Re: Samsung LN32c450E1D troubleshooting

Are there any output voltages from the power supply? Have you checked the fuse on the power supply?

[budm]

Re: Samsung LN32c450E1D troubleshooting

Any pictures? P/N of the power supply board?, ETC.

[airshac]

Re: Samsung LN32c450E1D troubleshooting

The fuse is good. I'm kind of thinking either I just need a remote to turn the tv on and then troubleshoot from there or I need to just replace the caps because they are bad in spite of not looking like it...

[budm]

Re: Samsung LN32c450E1D troubleshooting

Do you have test equipment such as Digital meter?
You need to take the DC readings on the white connector on the left side of the board, there are label close by telling you what each pins are. Black lead to the metal chassis, red probe on each pin of the connector.

[airshac]

Re: Samsung LN32c450E1D troubleshooting

I have an analog meter but can read it pretty well. What voltages should I be looking for? And I won't be able to get them till tomorrow night. Do you think I benefit from changing the caps just incase?

[tom66]

Re: Samsung LN32c450E1D troubleshooting

You will really need to get a digital meter. They are available for under $5 in most cases. Or borrow one. An analog meter will not have the resolution or accuracy that is needed for diagnosis.

[airshac]

Re: Samsung LN32c450E1D troubleshooting

Ok I'll pick one up today.

[airshac]

Re: Samsung LN32c450E1D troubleshooting

Tom66- I was looking through the service manuals you have posted, thank you! And I could not find one for a ln32c but the ln32b gives trouble shooting for a no power no red power light scenario. Will those diagnostic steps be the same for the C model?

[tom66]

Re: Samsung LN32c450E1D troubleshooting

They should apply for most LCDs, not just Samsung LN32C4xx series (Series 4 entry level LCD.)

[airshac]

Re: Samsung LN32c450E1D troubleshooting

Got the meter and will be testing the voltages this evening. So lets say that I test voltage at the connector and there is no voltage or very low voltage, does that mean the power converter is out? And do I need to order a whole main board or just replace the power converter(s)?

[airshac]

Re: Samsung LN32c450E1D troubleshooting

ok metered it out and have 2 rows of 9 pins each on the top row the pins are labeled b13v b13v b13v gnd gnd b5v b5v b13v b13v
row 2 first pin label to small to read second pin to small, 3rd pin e-??? (to small), hsyon (?) too small, gnd, gnd, b5v, a5v, ps_on (?)

All the 13v pins read 12.24, the 5v ones read 5.26, row2 pin 1 reads .01v, pin 2 reads 5.13,pin3 the e-??? reads .95v, pin 4 hsyon reads .003v, row 2 pin 9 ps_on reads .74v

One unexpected thing happened- I unplugged the connecting cable from the power supply board to the main board and the screen lit up but when I plugged the connecting cable in the screen went black.! Which showed me that it is cracked :/. Well it was a $10 tv from goodwill. So I'm still going to try to fix it. The power button still doesnt light up or do anything when I touch it...

[budm]

Re: Samsung LN32c450E1D troubleshooting

That means the power supply and the backlights inverter circuits are OK, the problem is the main board is not sending the PS_ON signal to turn on the power supply. The main board is keeping the PS_ON from going high (>3V = ON).
But since screen is broken, then that will not be worth to get new screen, especially for the 32" TV. You can sell the inverter board and the power supply boards to recover your $10 easily.

[skinamo]

Re: Samsung LN32c450E1D troubleshooting

I'm sorry to break in, but I can't post a new topic yet, thanks. Where can I find a definition of the codes for Samsung LCD TVs. I have a Samsung LN32C450E1D that flashes 6 times and then nothing. I did the checks of disconnecting the cable from the Main Board to the Power Supply. I got the back lights coming on, and then go off when the plug is reconnected. The following voltages were measured on that plug to chassis ground:
Pin 2 = 5.02v Pin 1 = 12.13v
Pin 4 = 4.87v Pin 3 = 12.16v
Pin 6 = 4.94v Pin 5 = 12.16v
Pin 8 = 0.00v Pin 7 = 0.00v
Pin 10 = 0.00v Pin 9 = 0.00v
Pin 12 = 0.00v Pin 11 = 5.19v
Pin 14 = 5.19v Pin 13 = 5.18v
Pin 16 = 5.18v Pin 15 = 12.18v
Pin 18 = 0.71v Pin 17 = 12.17v

Any ideas as to what else I can check? Thanks.

[budm]

Re: Samsung LN32c450E1D troubleshooting

Disconnect the cable o the T-CON board, so far your power supply board and inverter circuits are working, otherwise the backlights will not stay on when you disconnect the cable between the main board and the power supply board.
Service manual:
http://elektrotanya.com/?q=showresul...oria=&kat2=all

[skinamo]

Re: Samsung LN32c450E1D troubleshooting

Okay I disconnected the cable to the T-Con board, there is no difference. I would like to add that with every thing connected properly, and I press the power button on the remote control the following happens:
1. the red power LED flashes 6 times,
2. between the third and fourth flash there is a little melody played and the back lights come on,
3. there is nothing on the screen but it is back-lighted, it stays that way as long as power is on,
4. when power button is pressed to turn it off, the melody is again played as it turns off.

Where do I go from here? Thanks

[budm]

Re: Samsung LN32c450E1D troubleshooting

If the backlights stay on but no pictures on the screen, then need to check the DC voltage on both end of the SMD fuse on the T-CON BOARD with respect to the chassis ground, ithsould either have 5v or 12vdc depends on the T-CON design.

[skinamo]

Re: Samsung LN32c450E1D troubleshooting

Hi budm,
Backlights are on but there is no voltage on either side of the T-Con board fuse FP1. This board is situated at the bottom of the TV set, kinda hard to get at, but the fuse itself is visible and easy to take measurements from.

[budm]

Re: Samsung LN32c450E1D troubleshooting

OK, that means the main board is not supplying the voltage to the T-CON board through the switched MOSFET on the main board. You will have to trace the connection from the fuse back to the main board to locate that MOSFET.

[skinamo]

Re: Samsung LN32c450E1D troubleshooting

I've been searching for a diagram for this Main Board (BN41-01334A) but can't seem to find one. Can you assist me with a copy please. I was only able to find BN44-0039A which does not have the 30 pin connector to the T-Con Board. Thanks.