Samsung 226bw dead. No power

[da.chisel]

Hi,
My samsung 226bw recently died. It acted a bit weird in the last month (stays black, blinking blue led..) But now it is completely dead (no power at all, no blue led)

I have read some posts in these here forums and instead of replacing the caps myself, I went ahead and purchased another power supply (same exact model as I had previously).
Installed it, still no power. Then, after removing the pc-board behind the power button and playing with it, it turned on (blue led, but nothing else on the screen).
Then, it stopped working again.

I have checked the caps on both boards and nothing seems wrong.

what am I missing?

I feel like I just spent 40$ for a new power supply for nothing. Hopefully it`s something easy..

Thank you!
Da.Chisel

[retiredcaps]

Re: Samsung 226bw dead. No power

what am I missing?

1) Post pictures of your boards using the manage attachments button so the picture is hosted here.

We want clear focused pictures with the following composition as shown in

https://www.badcaps.net/forum/showpo...94&postcount=1

2) Do you have a multimeter?

[mockingbird]

Re: Samsung 226bw dead. No power

I just repaired one of these.

If you want a list of the caps from Newark, let me know.

[da.chisel]

Re: Samsung 226bw dead. No power

Hi, thank you guys for wanting to help me. I will try to take pictures this weekend and post them here.

(Edit)And no, I dont have a multi unfortunately..(/Edit)

The power supply I installed yesterday has no bad caps. It is guaranteed to be in working order, so I am removing that from the possible cause.

Thanks again.

[retiredcaps]

Re: Samsung 226bw dead. No power

And no, I dont have a multi unfortunately

Without a multimeter, troubleshooting will be very difficult.

[da.chisel]

Re: Samsung 226bw dead. No power

I will get my hands on a multimeter this weekend If I can.

Thank you,

[mockingbird]

Re: Samsung 226bw dead. No power

You're aware that even a "new" power board will have factory original capacitors on them, which means CapXon... You should still seriously consider the PSU caps as the problem.

[da.chisel]

Re: Samsung 226bw dead. No power

Ok. Here I have taken pictures of both the PSU and the other board, back and front.<

I also purchased a multimeter for the cause.

Be gentle, I have never used one of those devices before.

I will wait for your instructions.

Thank you,

[mockingbird]

Re: Samsung 226bw dead. No power

I see a combination of Samyoung, Capxon, and a third brand I can't identify... You should start by replacing all the electrolytics and thus eliminate them as a possibility.

[da.chisel]

Re: Samsung 226bw dead. No power

I see a combination of Samyoung, Capxon, and a third brand I can't identify... You should start by replacing all the electrolytics and thus eliminate them as a possibility.

I will consider that, thank you.

Is there a way to identify which one could be defective before replacing them all ? I would like to know what is wrong with this new board, to see if it is worth the investment I already put on it.

Thank you,

[retiredcaps]

Re: Samsung 226bw dead. No power

Ok. Here I have taken pictures of both the PSU and the other board, back and front.

Those are excellent pics. It helps a lot when remote troubleshooting.

I also purchased a multimeter for the cause.

You will find it a handy tool not only for this project, but around the house use as well.

Be gentle, I have never used one of those devices before.

Can you post a picture of your new multimeter so we know what you are using?

I also suggest viewing this 4:36 video on a multimeter tutorial. View it once all the way through and then view it again and pay attention to the 1:00 to 1:55 mark.

http://www.youtube.com/watch?v=bF3OyQ3HwfU

Then practice measuring a 9volt or AA battery to make sure your multimeter is working correctly.

After that, then you can move onto the next post.

[retiredcaps]

Re: Samsung 226bw dead. No power

Part 1.

Okay, now let's verify that you are getting what is the called the secondary voltages on your power board. Let's measure your replacement board.

Look at the attached pictures for the power board (the yellow one). Depending on how the board is installed (facing up or down), put your black probe onto the ground screw (denoted by the black spray paint). Obviously, the screw has to be put back in so that the black probe can actually touch it.

This is your cold ground. You will leave this probe here for all your measurements. Now set your multimeter to 20 V DC (if manual ranging).

Put your red probe on each pin (denoted by the red spray paint), one at a time, and record the pin number, its legend value, and the multimeter reading. So we want it reported like

pin 1 - legend says 12 V - dmm reports 12 V
pin 2 - legend says 5 V - dmm reports 4.99 V
etc

Be CAREFUL not to touch 2 pins at the same otherwise you may short out the board.

Part 2.

Let's measure the voltage regulators on the logic board (green board). Again, your black probe will go onto the ground screw (denoted by the black spray paint) and be left there the entire time. This is your cold ground.

Put your multimeter on the 20 V DC scale.

Put your red probe on each pin for each IC circled in red. The top part (tab) does not need to be measured. For example, on IC 601, there are 3 pins. Measure each pin with the red probe. Report it like this

IC601 - part number 17-33G
pin 1 = 0 V
pin 2 = 5 V
pin 3 = 3.3 V

[da.chisel]

Re: Samsung 226bw dead. No power

Here is a picture of my newly acquired multim. I will get to work tonight with the steps you have given me.

Thank you

[retiredcaps]

Re: Samsung 226bw dead. No power

Here is a picture of my newly acquired multim.

Did you buy this from Canadian Tire? If yes, I hope you got it on sale. They usually have multimeters on sale for about 60 to 75% off on a bi-weekly to monthly basis.

[da.chisel]

Re: Samsung 226bw dead. No power

Actually yes, got it from Canadian tire just this morning. It was 25$.

[retiredcaps]

Re: Samsung 226bw dead. No power

Actually yes, got it from Canadian tire just this morning. It was 25$.

Keep your eye on the Canadian Tire flyers that come out every thursday or friday in case it goes on sale. You can take the receipt back and get the price difference for up to 30 days I believe.

[mockingbird]

Re: Samsung 226bw dead. No power

I got a nice heatgun from Canadian Tire for 12 dollars last week eventhough it was being advertised as $15.

[da.chisel]

Re: Samsung 226bw dead. No power

Ok. Had the time to measure those tonight.

On the power board :

1 - on/off = 0
2 - A-Dim = 0
3 - 13.5V = 15.62
4 - 13.5V = 15.62
5 - 13.5v = 15.62
6 - GND = 0
7 - GND = 0
8 - GND = 0
9 - B-DIM = 0

On the logic board : (since I dont have pin numbers, I will refer to #1 as closest to the top of the board (ribbon cable) or closest to left of the board (power cable in)
Part IC602
17-18
#1 = 3.8
#2 = --
#3 = 0

Part ic204
6p738
#1 = 5.19
#2 = 0
#3 = 5.19

Part ic601
17-33g
#1 = 0
#2 = 3.15
#3 = 5.19

Part #ic702
1501-50
#1 = 15.62
#2 = 5.09
#3 = 0
#4 = 5.19
#5 = 0


Hopefully I did that correctly

I will await further instructions.

Thank you!

[retiredcaps]

Re: Samsung 226bw dead. No power

On the power board :

1 - on/off = 0
2 - A-Dim = 0
3 - 13.5V = 15.62
4 - 13.5V = 15.62
5 - 13.5v = 15.62
6 - GND = 0
7 - GND = 0
8 - GND = 0
9 - B-DIM = 0

Pins 3, 4, and 5 are a bit high, but that could be due to the inverter not drawing any power right now. Secondary voltages in lcd monitors may not be regulated and will fall to the specified voltages where there is a load present.

Since you have secondary voltages, this implies that the power portion of the replacement board is working. We don't know about the inverter section yet because of below.

On the logic board : (since I dont have pin numbers, I will refer to #1 as closest to the top of the board (ribbon cable) or closest to left of the board (power cable in)
Part IC602
17-18
#1 = 3.8
#2 = --
#3 = 0

IC602, if the readings are correct, is bad. The suffix -18 denotes 1.8 V DC output. What is --?

Part ic601
17-33g
#1 = 0
#2 = 3.15
#3 = 5.19

IC601 is also bad as well. The -33 denotes 3.3 V DC. You measured 3.15 which is low. A voltage regulator should be +/- 1% tolerance.

I will await further instructions.

The two suspect parts above are widely available. You can try your local electronics store. Take the board with you and tell them you want replacements. The parts should be less than $1 each.

The parts are also available through any online store like digikey, mouser, but the shipping costs to Canada is $8 USD. If you choose this route, consider what mockingbird said regarding the cap replacement as many local stores in Canada will not carry the proper low ESR caps (like Panasonic FM) that are required in a SMPS application.

Alternatively, if you have any old unused or junk boards (sound card, etc), you may find a suitable replacement. Just look for the correct size and suffix (-18 and -33).

You will also need a decent solder iron to remove those ICs. With my cheap "sort by lowest price" ebay solder iron, I cannot remove those types of component packages.

[da.chisel]

Re: Samsung 226bw dead. No power

-- meant that the connection does not go anywhere. The pin is cut and does not go into the board. So I figured it was useless to check it. But if you need this pin, let me know and I will check it.

I doubt that my local radio-shack will have these parts. And since I dont have any other parts laying around, I will have to go with digikey. My soldering iron is a 35w. A bit chunky tho.. I will see if I can get another one..

I thank you for this, you have been a great help. I will try my hand and repair this damned monitor once and for all..