Samsung TV Whoas

[ggenovez]

Hi all,

I have a 67" DLP samsung TV that I bought from Costco several years ago.

I've replaced the bulb several times.

This time something odd started to happen.

Initially, the standby light would flash and it would just take a little longer to get a picture. Then it was up to 2 minute, and now there is no picture at all.

The standby light just flashes.

Any ideas what may cause this?

Thanks

[tom66]

Re: Samsung TV Whoas

Many Samsung TVs have issues with bad capacitors on the power supply board, the problem affected most of their 2007 through 2010 LCDs and a lot of their DLPs too.

[ggenovez]

Re: Samsung TV Whoas

Thanks Tom,

Is there a cheat sheet on where they are? and do they just plug in / plug out or do I need to solder?

[tom66]

Re: Samsung TV Whoas

You will need to solder, if you cannot I recommend you find someone who can or learn how to. It's not a difficult skill to master.

As for where they are, I've never worked on a DLP but I imagine if you take the back cover off you will see some circuit boards. Post a picture of what you see and we may be able to help you.

[ggenovez]

Re: Samsung TV Whoas

Not a problem. I can solder.
k, will send pictures tonight.

[cashkennedy]

Re: Samsung TV Whoas

Generally its low esr caps, so would be located on the secondary side of the power supply board. , and often they will be visibly bloated / crud coming out the top. Post pictures and we will see.

[ggenovez]

Re: Samsung TV Whoas

Figured I would try to reset the TV. Unplugged it and plugged it back in and all of a sudden it started working.

Does this indicate a different problem or do I still need to tear into it?

[tom66]

Re: Samsung TV Whoas

Usually a problem that goes away on its own comes back just as easily. Try it for a few days, and see if the problem returns.

[ggenovez]

Re: Samsung TV Whoas

Looks like the problem is creeping back.

I'll send pictures of the power supply.

[ggenovez]

Re: Samsung TV Whoas

Sorry everyone, took longer than I expected.
Here is what I think I see

Location of color wheel and bulb



Video output


power supply


Yes, I know. It needs a thorough cleaning.

[ggenovez]

Re: Samsung TV Whoas

Ok, it is the last on, I followed the power cable and pulled it then did an image search and came up with the exact item. So How far from the capacitive rating is ok. For example I have a 1000uf that's reading 1100. I won't even mention the 2200uf that are reading OL

[kaboom]

Re: Samsung TV Whoas

Ok, it is the last on, I followed the power cable and pulled it then did an image search and came up with the exact item. So How far from the capacitive rating is ok. For example I have a 1000uf that's reading 1100. I won't even mention the 2200uf that are reading OL

Stop using it, unless you want to blow transistors/rectifiers. You're also overworking the other caps in the set, by dumping ripple into them which the PS caps should be filtering. Those surface mount electros, elsewhere in the set, can be a PITA to change.

Replace all of them, including the two large caps. I've used Nichicon HE and PW on the secondary side of these. The single (400V?) cap on the primary side of the standby supply can be increased in value. Nichicon CS or equivalent works here.

Also, the two big caps in the doubler on this board also feed ~300-340V to the UHP lamp ballast/power supply.

[ggenovez]

Re: Samsung TV Whoas

Thanks kb!

Sounds like you've done this once or twice.

Do you have a source for parts? What should my BOM look like?

[kaboom]

Re: Samsung TV Whoas

Mouser will have everything you need. Which is good, since you're close by.

It's actually been almost three years since I worked on one of those, so I don't remember exactly what I used. Not that it would matter, since I "upgraded" some of those caps to larger values than they originally were.

It would be a big help if you took some close up pix of your board.

Probably similar to the following:
Secondary:

3300u 25v x2
1200u 25v x3
680, 820, or 1000u 10v x5
2200u 16v x2 (3?)

Primary:

82u or 100u 400v
820u 200v x2
47u 50v
22u 50v x2

It's been a while... Some of those are values I "picked" from, I didn't actually use that many caps.

Don't go by that list without checking your board first!

I can tell you that these sets can produce an amazing picture, at least when provided with a serious signal. Also, it's possible to replace just the lamp, instead of the housing+lamp. Bare Philips lamps are about $100.

Good TVs, except for the PS caps.

[ggenovez]

Re: Samsung TV Whoas

Better picks? is that all you need?

http://s294.photobucket.com/user/gge...ary/Snapbucket

[kaboom]

Re: Samsung TV Whoas

Better picks? is that all you need?

http://s294.photobucket.com/user/gge...ary/Snapbucket

Looks good, but I need the value or pix of those two in the green square.

I think those are both 1000u, 10v, but need confirmation.

[ggenovez]

Re: Samsung TV Whoas

Confirmed. 1000 uf. 10 v

[kaboom]

Re: Samsung TV Whoas

Confirmed. 1000 uf. 10 v

I thought they were...


Here's a Mouser list. I have subbed a few caps for bigger ones.

-Paul

[ggenovez]

Re: Samsung TV Whoas

Paul. You rock. Thx!

[kaboom]

Re: Samsung TV Whoas

You're very welcome.

Good luck with your repair!