Samsung 245BW - Quick diagnosis

[33k!]

I am busy reading all the 245BW threads around this great site.
I am hoping that an expert can shed some light on my problem, I seem to have a different problem than everyone else.

My 245BW works great unless you turn it off for 2-3 days. If you turn it off for only 10-12 hours it powers on and works great, but if you turn it on after 2-3 days powered off, the blue led turns on and then turns off. You can power on 10-12 tiimes like this, then it will turn on.

It seems a cap is charging, but faulty, maybe?
Thank you everyone for a great forum!

[selldoor]

Re: Samsung 245BW - Quick diagnosis

I am sure I have read this problem many times!

Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed

https://www.badcaps.net/forum/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246

It will be useful if you can say a bit about yourself - skills tools etc.
and what tests you have already carried out.

[33k!]

Re: Samsung 245BW - Quick diagnosis

I am a beginner that has used an iron to make audio cables , has taken physics in university, and owns an auto-ranging digital multimeter.

I am hoping someone can shed some light on my potential problem before I open up the chassis.

Thank you very much!

[UniT3d]

Re: Samsung 245BW - Quick diagnosis

Hmmm .....

Sounds like some busted caps to me ..... go ahead open 'em up and take a peek

[33k!]

Re: Samsung 245BW - Quick diagnosis

[selldoor]

Re: Samsung 245BW - Quick diagnosis

Needs a good dust and all that brown Glue removed then test the 3x 68 ohms resistors
bottom Pic xxx753.jpg

[33k!]

Re: Samsung 245BW - Quick diagnosis

Resistors are all 68, my neighboor is telling me that the three 10V caps should be something bigger, like a 35V

[budm]

Re: Samsung 245BW - Quick diagnosis

Did you remove ALL those glue yet, on picture DSC03759, the yellow glue (on the lft side of the IC) turns dark brown and it is on the high voltage snubber circuits for the that 5V STVBY IC. It is may be conducting. You must remove those glues from ALL locations.

[33k!]

Re: Samsung 245BW - Quick diagnosis

Ok, its dusted off. Lots of brown glue in different places. How should that be removed? pliers and cut it off? Acetone? Does it matter if some remains, just that it shouldn't short anything by touching something else?

[budm]

Re: Samsung 245BW - Quick diagnosis

I trim off as much as I could with cutter/knife then use Alcohol to remove the rest. The glue will eat away conductors and leads, and copper traces. Since it is also conductive so if it is on the legs of two component, it will conduct current.

[33k!]

Re: Samsung 245BW - Quick diagnosis

Ok, got the glue removed, mostly. Unfortunately, I broke the data cable going from the video card to the screen. Is it possible to find this item for sale somewhere?
The connector has 070228-3 stamped on it

[Toasty]

Re: Samsung 245BW - Quick diagnosis

Let's see the video cable and damage. Someone may have one laying about, or a way you can repair it.

These PSU (BN44-00173A) are usually a recap and the 3 resistors to fix. Also, the mains cap can fail and the 18nF / 600v blue rectangular cap next to it. There's a pile of discussions in here about them and a few variations.

T

[33k!]

Re: Samsung 245BW - Quick diagnosis

Here is the cable, its from the video controller card to the video display panel. It doesn't look damaged , but it is very delicate and i bent it very bad, its cracked on the other side.

[selldoor]

Re: Samsung 245BW - Quick diagnosis

Do you mean the connector is cracked or the insulation on the wires

[33k!]

Re: Samsung 245BW - Quick diagnosis

On the left side of the connector you can see the connector if cracked, missing plastic. There is a crack under that missing plastic, as well

[UniT3d]

Re: Samsung 245BW - Quick diagnosis

Hmmm .....

Maybe a tiny dab of super glue for the crack? Test to see whether that exposed pin goes to pin 1 (vss ground) or pin 30 (+ Clock Input)? Maybe you want to try patching it up (the bents) the best you can? Finally once the super glue sets in, see if it still works plugged-in?

Looking at the pics, I'd probably give it a shot ... but I guess that's your call ...

[selldoor]

Re: Samsung 245BW - Quick diagnosis

I would go for quicksetting epoxy- superglue tends not to work on gap filling. If you want to use superglue you can get it to fill gaps by using it with baking powder/baking soda. Perhaps try it on something else first so you see how it might work.

Looking again at the pic you should be able to build it back using sg applied with a pin and bs with a toothpick shaped like a screwdriver