Samsung LN26A450C1D No Power

[canadapettit]

Hello everyone,

First time posting here but have viewed the site before. I have a Samsung
LN26A450C1d that will not power on. The red stand-by light is also not lit up. Pulled the back off and did not see any notice able bad caps but put the ESR meter on them and they all check fine. Any ideas on what might be bad?





Sorry for the small pics, best i could do. If you need anymore info just let me know

[cmj21973]

Re: Samsung LN26A450C1D No Power

Going to need bigger pics.
Check for open fuses.

Download SM here.
http://www.4shared.com/office/NSHzyd...N40A450C1D.htm

[selldoor]

Re: Samsung LN26A450C1D No Power

You need to repost the pictures - if you go to go advanced by clicking under Quick reply
you will see what to do under manage attachments Max file size for a jpg is about 1.3mb and should be no bigger than 2000x 2000

Straight on ones are best we should be able to read the part numbers - you should also have pics of the backs of the boards.

[canadapettit]

Re: Samsung LN26A450C1D No Power

I will get better pics tomorrow when i get back to work. I checked for any other fuses and didn't find any other then the ceramic gma fuse which is fine. Looking at this pic here, all of the caps in the upper left all check fine. power is getting to the rectifier and the large cap but thats about all i know. The s/m that was posted earlier didn't really have kind of schematic for the power supply so if anyone else has a power supply schematic that would be great.


By canadapettit at 2012-02-21

[PlainBill]

Re: Samsung LN26A450C1D No Power

Please add 'Post picture of power supply output connector' to your 'to Do' list. It's shown in the first picture, but not in the full size one. Also, if there is any legend identifying the pins, include that.

PlainBill

[canadapettit]

Re: Samsung LN26A450C1D No Power

Will do Bill. When i checked the power supply there were no voltages on any pins. That tells me the secondary is completly shot but i am hoping for a different answers.

[flamike]

Re: Samsung LN26A450C1D No Power

looks like smut on that 12 k resistor from mosfet maybe?

[canadapettit]

Re: Samsung LN26A450C1D No Power


By canadapettit at 2012-02-22

By canadapettit at 2012-02-22

By canadapettit at 2012-02-22

By canadapettit at 2012-02-22

[canadapettit]

Re: Samsung LN26A450C1D No Power


By canadapettit at 2012-02-22

By canadapettit at 2012-02-22

[canadapettit]

Re: Samsung LN26A450C1D No Power

If any more pics are needed just let me know. The resistor has some browning to it but it still measures .12 ohms as it should. the diode and transistor that it is next to check fine also.

[budm]

Re: Samsung LN26A450C1D No Power

You need to check and see if the 5VDC standby power supply section is working first. The IC with a samll heatsink is the IC that drive the transformer close to it for the 5vdc stby P.S.
Service manuals:
http://elektrotanya.com/?q=showresul...at2=schematics

http://s807.photobucket.com/albums/yy352/budm/SAMSUNG/

[Scenic]

Re: Samsung LN26A450C1D No Power

This might be of some help, despite being Rev. A (BN44-00208A) instead of B.
Connector- and part designations as well as output voltages are identical compared to the above photos.

edit: crap.. didn't notice the link cmj21973 posted, which might have the correct Rev. B PSU stuff in it.

[canadapettit]

Re: Samsung LN26A450C1D No Power

Scenic that one is close but not the same one. The service manual above doesn't have the whole psu schematic in it unfortunately. if you come across the correct one please share it. thanks

[selldoor]

Re: Samsung LN26A450C1D No Power

There are very few schematics out there for Power Boards for Samsung
monitors.

I did ask you not to post photos in line? - some members will not even look at the thread because of that.

You keep asking what more pictures do we want but havent yet posted one of the backs of your boards.

Have you checked/replaced the smaller caps?

[budm]

Re: Samsung LN26A450C1D No Power

I am a little confused to the word "not to post photos in line", what does it mean? I do not want to make mistake when posting pictures.
How do I suppose to post the pictures here? I am still new at this. Thanks for directions in this matter.

[selldoor]

Re: Samsung LN26A450C1D No Power

I am a little confused to the word "not to post photos in line", what does it mean? I do not want to make mistake when posting pictures.
How do I suppose to post the pictures here? I am still new at this. Thanks for directions in this matter.

Hi Bud
The pics in this post are posted inline- I guess just using paste. I dont know as ive never done it. It means that every time the thread is viewed the pictures are loaded fully Some people load up several pictures 5 mb each whether you want them or not. Some of our members to not have wizzy super broadband and so rather than wait for it to load they just move on to the next thread. If you load using the system it just puts a thumbnail on if logged in or a link if not logged in, and you can then choose to load it fully or not.

For best picture quality and clarity take your boards to a window on a sunny day, turn flash off, and use macro mode. Take a top down view of all your boards (front and back). Make sure the photo is legible so that we can read the PCB printing clearly. A shutter speed of 1/125 or faster will produce nice clear focused pictures. Try to get a photo that is 2000x2000 resolution or as close as possible.

This post has an example of the pics we want
https://www.badcaps.net/forum/showpo...94&postcount=1

To post pics do not use Quick reply but go to "go advanced" box below
Then in additional options select "Manage attachments "
You can then upload from your pc or from a URL .

The max file sizes are shown, if exceeded it will reject.

The PDFs do not always load and you will just have to put links in for them.

I hope this of some help to you

[retiredcaps]

Re: Samsung LN26A450C1D No Power

I am a little confused to the word "not to post photos in line", what does it mean? I do not want to make mistake when posting pictures.
How do I suppose to post the pictures here? I am still new at this. Thanks for directions in this matter.

Hi Budm,

1) Glad to see you are participating as I know you have a ton of knowledge.

2) Here are my reasons for NOT posting pictures inline.

https://www.badcaps.net/forum/showpo...5&postcount=12

add #10

10) Pictures that are posted inline is like forcing me to watch a commercial whether I want to or not. It is like not have a skip or fast forward button on your remote control when watching something on the VCR or PVR.

3) No, I'm not anal retentative about this issue, but if it is too hard for me to help someone for the above reasons, I move onto the next thread. After 5,000 posts and almost 2 years of participation, unwanted popups, virus warnings, resizing gets tiring after a while. I even changed my sig file to reflect my feelings on this sometime last year.

[lpettit]

Re: Samsung LN26A450C1D No Power

My bad on the inline picsture. From now on i will not use imageshack to host, but the only reason i did was because the managed attachments would not work. But regardless i think i may have solved the problem. The ic with the small heatsink on it should have 12 volts on pin 5 i believe on start up to switch the power supply on but it never reaches 12 volts so i ordered a new one and we shall see what happens.

[Scenic]

Re: Samsung LN26A450C1D No Power

If uploading photos via forum attachments fails, it's usually because the pics are too big (more than 2000x2000 pixels or the files are larger than 3.81 MB).

You can use a free image viewer like IrfanView to resize them if needed.
If you decide to use that one, just make sure you untick the additional software it wants to install with it (usually Google Chrome). See first attached screenshot.

Once you're in Irfanview, open the picture you want to resize, click on "Image" in the toolbar and select "Resize/Resample" (or just use the Key-Combo CTRL+R).

Enter "2000" in the field below the larger number.
i.e.: if current size shows "2304 x 1728 Pixels", you'd use the first (width) field.

Hit OK, check the result and if it's fine (not stretched or anything), you can save it, using either File -> Save As or by just hitting "S" (does the same thing).

The attachments under my post show examples of this.

If you want to, you could also use the "Batch conversion" menu entry in the "File" menu, instead of resizing every image by hand. However, the settings menu of that looks a bit daunting to a beginner (tons of options).

[selldoor]

Re: Samsung LN26A450C1D No Power

My bad on the inline picsture. From now on i will not use imageshack to host, but the only reason i did was because the managed attachments would not work. But regardless i think i may have solved the problem. The ic with the small heatsink on it should have 12 volts on pin 5 i believe on start up to switch the power supply on but it never reaches 12 volts so i ordered a new one and we shall see what happens.

Hi - now you really trying to confuse us - presume you are the same person
as the original poster?