T-con Samsung identifying problem

[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

[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

[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.

[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

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.

[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

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

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.

[cliff_hootarski]

Re: T-con Samsung identifying problem

Might try it just for grins.

[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.

[budm]

Re: T-con Samsung identifying problem

Hi, Thanks for responding

Do not have an oscilloscope to test, my be able to get one next week from work.

The two boards have now changed their voltages!

The original board has now dropped to 4.6 at in test point.

The second hand board has now dropped to 5.45. It is also now making a ticking sound.

To try and eliminate the power issue I tried taking a power adaptor with variable power setting: Removed the fuse in the T-Con. Set the adaptor to DC 12v. Earthed it to the frame and connected the positive to the "in" end of the fuse connection. It give these results:

Second hand unit just keep fluctuating voltage and ticking.

Old unit held at about 11v with panel connector off but dropped again to 4.6v when connected back up.

Do not know if this would eliminate the need for the oscilloscope and its meaning

Will id SMD's ASAP. I would upload a hi res image of the board so all the IDs can be seen but everytime I try to upload it it fails even though it meets the size and resolution guidelines.

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?

[cliff_hootarski]

Re: T-con Samsung identifying problem

Try this to resize your pictures to match board requirements:

http://picresize.com/

[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.

Hi, Thanks for responding

Do not have an oscilloscope to test, my be able to get one next week from work.

The two boards have now changed their voltages!

The original board has now dropped to 4.6 at in test point.

The second hand board has now dropped to 5.45. It is also now making a ticking sound.

To try and eliminate the power issue I tried taking a power adaptor with variable power setting: Removed the fuse in the T-Con. Set the adaptor to DC 12v. Earthed it to the frame and connected the positive to the "in" end of the fuse connection. It give these results:

Second hand unit just keep fluctuating voltage and ticking.

Old unit held at about 11v with panel connector off but dropped again to 4.6v when connected back up.

Do not know if this would eliminate the need for the oscilloscope and its meaning

Will id SMD's ASAP. I would upload a hi res image of the board so all the IDs can be seen but everytime I try to upload it it fails even though it meets the size and resolution guidelines.

[fzabkar]

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.

[wilson_campbell]

Re: T-con Samsung identifying problem

Fig 34, page 33 of the following datasheet (for ICD1) appears to have an application circuit that is similar to your own.

TPS65167A, Texas Instruments, Compact LCD Bias Supply for TFT-LCD TV Panels:
https://cdn.badcaps-static.com/pdfs/...6c316493a3.pdf

There should be a voltage of around 15V at the AVDD test point at the cathode of SD1.

I can see VOFF and VSS test points above L2 on your board.

ICD1 also has VGL (-8V) and VGH (+24V) outputs (according to the datasheet).

QD1 is a 2SA1718 PNP transistor for the Vcore supply (+1.2V).

2SA1718, PNP, -100V, -5A, Darlington:



I can't make sense of the part marking on ICD2.

There are also VON and VOFF test points at the bottom left corner of the T-Con PCB.

icd2 is 443/ on it. It was a very hard to see.

[wilson_campbell]

Re: T-con Samsung identifying problem

I was wondering why the first panel had a supply voltage of 5V instead of 12V. Now that you've cleared that up, perhaps someone could rescue me from my ignorance and tell me what the AVDD supply is used for. :-)

Looks like noone is interrested anymore

[fzabkar]

Re: T-con Samsung identifying problem

I was wondering why the first panel had a supply voltage of 5V instead of 12V. Now that you've cleared that up, perhaps someone could rescue me from my ignorance and tell me what the AVDD supply is used for. :-)

[wilson_campbell]

Re: T-con Samsung identifying problem

Yes just striped the control board of the back and there is a sticker underneath. It is:

LTF320AB01
0904
P8AE 8M9A0S060K A03 S64 (AP+)

This must be the panel ID.

Sorry for all the wrong info given everyone

[wilson_campbell]

Re: T-con Samsung identifying problem

This panel might be the correct version:

*** Just notice the Service manual later on list a different panel number again: M0215 BN07-00538A LCD-PANEL;LTF320AB01,8bit,32inch,16.7M,1 1 S.A in the exploded list that contradicts the original.

[wilson_campbell]

Re: T-con Samsung identifying problem

What is the LCD panel model number?

Got this from the service manual:

M0215 BN07-00511A LCD-PANEL;T315XW02 VL,8bit,32inch,16.7M, 1 S.A

and found file attached.

Do not know if it is correct as the number of pins outlines seem 2 pins short as I count 32 on the board. Maybe some are not used?

service manual to big to attached. Cut and paste below:
5. Exploded View & Part List
5-2-1. LE32A45*C** Parts List
Location No. Code No. Description & Specifi cation Q'ty S.A/S.N.A Remark
T0003 BN96-06784E ASSY COVER P-FRONT;32L456,EO(iDTV),ABS+P 1 S.A
M0215 BN07-00511A LCD-PANEL;T315XW02 VL,8bit,32inch,16.7M, 1 S.A
T0175 BN96-06818C ASSY SPEAKER P;8ohm,CORAL,L450,10W,550/3 1 S.A
M0115 BN61-02947A BRACKET-STAND LINK;JASMINE 32”,SECC,T1.6 1 S.A
M0254 BN61-03699A HOLDER-SIDE AV;32L450,EO,HIPS,V0,-,-,-,B 1 S.N.A