Dead Samsung DTB H260F

[maybenever]

This is a stand alone antenna HD signal receiver. I use it with a Mitsubish HD ready TV that does not have it's own receiver. Whithout warning, it powered off and will not do anything. It has a fuse inside the case, but it's good and has power going thru the fuse. There are two boards inside, I see nothing that looks wrong anywhere. I'm verrrry new at this, but would like to repair this thing, I need it. Any help on where to start?
Thanks

[seanc]

Re: Dead Samsung DTB H260F

Please take photos of the boards, in good light, preferably without flash to avoid glare.
You can attach them using the 'manage attachments' button when you reply using the advanced editor.

[maybenever]

Re: Dead Samsung DTB H260F

Will have them shortly.
Thanks

[maybenever]

Re: Dead Samsung DTB H260F

Having trouble uploading photos. I'll keep trying.

[maybenever]

Re: Dead Samsung DTB H260F

Had a little trouble attaching files. I hope you can tell something from these.

[Agent24]

Re: Dead Samsung DTB H260F

Are there any voltages on the PSU output at all or is it completely dead?

[maybenever]

Re: Dead Samsung DTB H260F

Dead as far as I can tell.

[maybenever]

Re: Dead Samsung DTB H260F

Exactlly where do I start checking for voltage?

[jetadm123]

Re: Dead Samsung DTB H260F

Exactlly where do I start checking for voltage?

If you look at the bottom wiring harness that connects the power supply to the logic board, you should see the voltages silk screened on the circuit board. Also, maybe on the top wiring harness too. Hard to tell from your photos.

[maybenever]

Re: Dead Samsung DTB H260F

I am getting voltage from power supply. Three wires marked 3.3v measure 3.39v, two wires marked 6v measure 8.63v, one marked 14v measurses 18.2v
What next?

[jetadm123]

Re: Dead Samsung DTB H260F

I am getting voltage from power supply. Three wires marked 3.3v measure 3.39v, two wires marked 6v measure 8.63v, one marked 14v measurses 18.2v
What next?

I'm going to take a guess and say that the 6V and 14V ouputs are unregulated and will drop when the unit powers up.

Check to see if there are any small surface mount fuses on the logic board.

[Agent24]

Re: Dead Samsung DTB H260F

https://www.badcaps.net/forum/showthread.php?t=12378 talks about bad capacitors giving higher voltage readings and causing problems.

May be your issue, maybe not... you're not going to know without testing them or replacing them.

Are there any other rails? What labels does the top wiring harness have?

[maybenever]

Re: Dead Samsung DTB H260F

Top wiring harness labels are SEL0, SEL1, GND, HDMI-CTL, NC, NC
I don't see anything marked as a fuse on board, but like I said, I'm very new at this.

[jetadm123]

Re: Dead Samsung DTB H260F

In order for members to help you, we have to see what you're seeing. Personally, I can't make out any components that would help me suggest what to test next. Please post some clear closeup photos of both boards (top and bottom) per the link below:



https://www.badcaps.net/forum/showthread.php?p=118105

[jetadm123]

Re: Dead Samsung DTB H260F

WOW! There's a 4 page thread on your same model here:

https://www.badcaps.net/forum/showthread.php?t=7804

[maybenever]

Re: Dead Samsung DTB H260F

I hope these are better.
Thanks for your time & help.

[jetadm123]

Re: Dead Samsung DTB H260F

WOW! There's a 4 page thread on your same model here:

https://www.badcaps.net/forum/showthread.php?t=7804


The photos will come in handy if the above link doesn't help.

[Agent24]

Re: Dead Samsung DTB H260F

You could have the same problem as the others in that thread - does the blue light (I assume power light) come on like theirs?

But your capacitors aren't bulging - then again, they can fail without doing that. Although it looks as if 2 of yours are kinda indented? Weird...

[maybenever]

Re: Dead Samsung DTB H260F

Wonder why that thread didn't come up when I searcded for it. O well.
My box doesnot show any live when powered on, not even for 1/10 of sec.
The bulging caps you mention, are those the brown ones? I can get a better close up of those for ya.

[jetadm123]

Re: Dead Samsung DTB H260F

Looks like the link describes power supplies that won't start up. Since you're getting 3 output voltages, it looks like the power supply is working, but the logic board is not getting power.

1) Check under the logic board for surface mount fuses. They are generally marked FX (where "X" is a number).

2) What are the part numbers of the devices I circled?