Samsung B2330H Dead

[budm]

Re: Samsung B2330H Dead

If you look at the spec of the IC, as you can see, pin 6 receives the start up voltage from the main power supply. Whne the IC starts running successfully, the IC will get the sustaning voltage from one of the winding of the transformer which wil be used to generated the DC voltage for the IC VCC pin 3 (just think of your car, once the car starts running you can disconnect the batteries since the alternator will take over and generate the voltage for the car), as you can see, there is the 47uf cap just the same as your monitor (Most manufacturer will just copy the circuit from the IC manufacturer). Waht you can do to find out if the IC does even startup or not when the power is first applied to the unit is to attach resistor (1,000 Ohms) in series with the LED across the 47uf cap, you should see the LED flashes which wil indiacte that the IC did try to start up. So try that first.

[VaNDAL_UK]

Re: Samsung B2330H Dead

Checked the 47uf 50V cap and there is no life or voltage going to it.

Seems a bit odd - where were you measuring? what was meter set on.
was board switched on? (it does happen)

With meter on 600vdc black lead on negative leg of big cap
take readings on each end of the 3 diodes on each side of the start up cap.
Remember this is high voltage area so care

Hi,

Thanks for the input I have done what you said:

600vcd on the meter
Black to negative on the big cap
and checked the diodes

All dead.

[VaNDAL_UK]

Re: Samsung B2330H Dead

If you look at the spec of the IC, as you can see, pin 6 receives the start up voltage from the main power supply. Whne the IC starts running successfully, the IC will get the sustaning voltage from one of the winding of the transformer which wil be used to generated the DC voltage for the IC VCC pin 3 (just think of your car, once the car starts running you can disconnect the batteries since the alternator will take over and generate the voltage for the car), as you can see, there is the 47uf cap just the same as your monitor (Most manufacturer will just copy the circuit from the IC manufacturer). Waht you can do to find out if the IC does even startup or not when the power is first applied to the unit is to attach resistor (1,000 Ohms) in series with the LED across the 47uf cap, you should see the LED flashes which wil indiacte that the IC did try to start up. So try that first.

I put an LED and resister across the 47uf 50v cap and plugged in the AC. Again nothing at all!

The big cap is reading 337V

[budm]

Re: Samsung B2330H Dead

What Dc voltage do you get at pin 6 of the IC? make sure to use the negative leg of the main (primary) Dc filter cap as the ground point when work on the primary side.

[VaNDAL_UK]

Re: Samsung B2330H Dead

main (primary) Dc filter cap?

The 400v one?

[budm]

Re: Samsung B2330H Dead

Yes, and be real careful to to touch anything in that section with your hands or body. post #41 diagram should be real close to what you are working on.

[VaNDAL_UK]

Re: Samsung B2330H Dead

Hi guys,

Thank you for all the previous help! I learned allot!!

Sorry for not replying sooner had the family fall down with the flu the past couple of weeks!

However I have since ordered and received a new power board for this monitor. Last night I connected it all up and tested. The monitor is still dead!

Upon closer inspection this monitor has no physical switch just these annoying touch sensitive buttons.

I removed the cable from the touch PCB and the screen turned white, reconnecting the cable to the touch PCB turned the monitor off. No blue LED on the touch PCB was on at anytime though!

Also the back of the touch PCB there is a mega small component that get hot enough to start stinging if held against the back of your hand.

I'll provide some hi quality pictures later to show the AV PCB and the Touch sensitive PCB.

[VaNDAL_UK]

Re: Samsung B2330H Dead

Here are the pics of the AV board.

[VaNDAL_UK]

Re: Samsung B2330H Dead

OK had abit of luck frustratingly!!

Swapped back to the original powerboard and plugged everything in still dead.

Unplugged the touch board and the monitor sprang into life with a difference!! The screen is nolonger white and is displaying fine!

However plugging in the touch board shuts the monitor down. There is a very small black component on the touch board right behind where you press for the power, this component get very hot!

I have took some readings from the AV board with the touch bard connected and not connected..

Please see pics.

[VaNDAL_UK]

Re: Samsung B2330H Dead

Got it all working now!! Typing using the monitor now.

I decided to remove the over heating component from the touch board.

Thanks for all the dedicated help!