T-con Samsung identifying problem

[wilson_campbell]

Re: T-con Samsung identifying problem

Try this to resize your pictures to match board requirements:

http://picresize.com/

Hi,

Thanks I have my own graphics tool called fireworks I use and even when I reduce it to match the requirements for a jpg it always fails the upload.

[cliff_hootarski]

Re: T-con Samsung identifying problem

Might try it just for grins.

[fzabkar]

Re: T-con Samsung identifying problem

ISTM that the consus is that the panel is killing the T-Con PCBs. Perhaps it's time to start learning how these panels and T-Cons work. I'd still want to know the part numbers of the other ICs.

[wilson_campbell]

Re: T-con Samsung identifying problem

I'm very interested, but I don't know enough to help you. If I were troubleshooting your T-con PCB, I would identify all the other chips and attempt to understand how the board and panel work. Can you tell us the markings on the remaining ICs?

AISI, even when the input to the board is only 9V, ICD1 should still be able to boost the AVDD supply to its design value, probably 15V. However, it is only achieving 9.9V. Therefore something is wrong in this area. It may also be that the incoming 12V supply has high ripple which only shows up when the supply is loaded. Perhaps you should check the filter capacitor for this rail on the PSU. This high ripple could also explain why the AVDD boost converter is not functioning correctly. You would need an oscilloscope to see this.

Another thing you could do would be to determine where the AVDD supply goes. To this end I would set my DMM on diode/continuity test mode, touch one probe to the AVDD test point, and then buzz each of the ICs with the other probe.

Managed to get some pics that are OK and converted to PDF. You should be able to zoom in and see the codes on the SMD's.

[fzabkar]

Re: T-con Samsung identifying problem

I can only make out the part numbers of the MAX9590 and the SDRAM.

However, it appears that the AVDD supply feeds the MAX9590, and this IC then drives 18 "reference buffers" for the panel. I would measure the resistance between ground and each of the OUT1 - OUT14 pins and OUT_REFx pins (13-19, 32-38, 1, 12, 20, 31). I would do this with the panel connected. If any pin shows a low resistance, then I would retest this pin with the panel disconnected.

MAX9590, Maxim, 14 Programmable Gamma Reference Buffers with Four Static References for TFT-LCD Displays:
https://cdn.badcaps-static.com/pdfs/...b12aa79458.pdf

[wilson_campbell]

Re: T-con Samsung identifying problem

That sounds to me like the panel is drawing too much current, it can be shorted MLCC, or the driver ICs. Did you check the current draw of the T-CON? Per LCD panel spec, it is typical at 1.2A.
Is the ticking sound coming form those two round inductors?

Removed fuse on t-con and checked current flow and it is only showing 0.04a on the multimeter (black on one end of fuse plate and red on other end). This is the same for each board and the same with the panel connector cable off or connected.

Checked it in the cable itself coming from the control board by removing the cable from the t-con and connecting to one of the 12v pin and other end to a ground pin. Gives same reading. So even though there is 12volts it does not seem to have any real current.

Attached spec for panel seems to show 0.55 needed.

[budm]

Re: T-con Samsung identifying problem

40mA does not sound right at all. 550mA typical, 6A inrush.

[wilson_campbell]

Re: T-con Samsung identifying problem

Trace possible problem back to power gate mosfet in control board. Some burn marks on it. Must have happen when the PSU problem existed as not overheating now. Could also be one of the nearby resisters.

Mosfet is SI3443BDV showing as [B]FET-SILICON;SI3443BDV,P,-20V,+-4.4A,65mo in service manual.

[wilson_campbell]

Re: T-con Samsung identifying problem

Replaced MOSFET with compatible. The plates where also off the board so had to scrap back to get contact points. The MOSFET only about 3mm long and hard to work with but got working with near enough amps to spec at t-con. My original t-con did not work. Second hand one lasted 2 seconds again but got a refund for after a lot of arguing and extremely bad customer service from the business ebay seller. Ordered another from a different seller and fitted and now working perfectly.

Thanks everyone for there helpand advise

[fredaelsadany]

Re: T-con Samsung identifying problem

HI ALL
till now this samsung not repaired why we do repair step by step .
first step is shown in the pic >
if you do it first it will insure TPS65167A IS GOOD after that we can continue.
thank you