Samsung 193P S - no power, power button not lit

[yzy]

Hi,

I have a trouble with Samsung 193P S - type no: GH19GS. Does not lit power button - tried with two power supply units. No traces of display in the strong light.
I'm sorry for the poor quality of pics. If necessary, I could make a sharper ones in the few hours.
It seems that the boards are more integrated these days than it they used to be in the older displays.
What should I test?

regards,
Dominik

[budm]

Re: Samsung 193P S - no power, power button not lit

Where is the DC INPUT JACK, or the power supply board?
Pictures of the whole backside that show everything?

[yzy]

Re: Samsung 193P S - no power, power button not lit

*update* I reassembled it, now there is power, power button is lit. Still no image, no backlight. No image when viewed towards sharp light. Cable that is attached to pin connector has 14V.

Where is the DC INPUT JACK, or the power supply board?
Pictures of the whole backside that show everything?

Please see the picture attached to this message. DC Jack is in the foot, power 14V power cabling + video goes inside the foot to the chasis and is connected to the board with two of those pin connectors you could see in my first post.

There is not much besides what I've attached in the first post; just two boards + typical connector to the lcd matrix + connector to the power button board.

[budm]

Re: Samsung 193P S - no power, power button not lit

No backlights can be due to no BL-ON signal, bad inverter circuit, blown fuse for the 14V feeding the inverter.
No pictures: due to bad T-CON board, no 5V from the man board to the T-CON board, bad main board.
There is no any labels for the pins on the connectors to find out what each pins are for so it is not going to be easy troubleshooting.

[yzy]

Re: Samsung 193P S - no power, power button not lit

Thank you for reply. I'm going back to this monitor next week (so no updates till then).
Should 5V be present on the connector from power supply to the board, or (just) between the two boards (display <> inverter)?

[budm]

Re: Samsung 193P S - no power, power button not lit

The 5V (it may also run on 12V, need to get the spec sheet of the LCD panel to find out) for the T-CON on the LCD panel is fed through a electronics switch that is turned on when power switch is activated. There are Voltage regulator ICs and buck regulator circuits on the main board that need to be check but you will need to get the spec sheet of those parts to get the pinout and to see how they function.

[Behemot]

Re: Samsung 193P S - no power, power button not lit

The fuse burns quite often in these displays. Also the brick adapters often go bad with bloated caps. You than troubleshoot why you see waves in the image for half an hour till you crack the PSU open and than it's obvious

The problem is often the bloated caps can still handle the ripple with no load. But as you connect the load it goes sky high.Often with bad priamry cap you see 100Hz ripple in there.