Samsung Celebrity Tv with an odd power issue

[Sealtest]

Hey all, a buddy of mine brought me a Samsung celebrity tv he would really like to have going. The problem with this set is that it powers up for only a couple seconds, then it shuts itself off. With a problem like this I am not too sure where to start looking.

Any help would be great!

[zeno]

Usually the power supply isnt regulating & triggering HV shut down ( HVSD )
Could also be over current in HV such as a bad FBT.

To diagnose safely you need a variac & AC amp meter.

1) unplug the degausser.
2) hook meter in series with AC line.
3) plug in to variac set at apx 90 V
4) turn on but DONT let the meter go above 1 amp.
If it draws over an amp its 95% HV.
If it stays on its 95% power supply.
Sometime a set wont start at 90 V. turn up a little at a time till it starts.

73 Zeno
LFOD !

[dieseljeep]

Originally Posted by zeno

Usually the power supply isnt regulating & triggering HV shut down ( HVSD )
Could also be over current in HV such as a bad FBT.

To diagnose safely you need a variac & AC amp meter.

1) unplug the degausser.
2) hook meter in series with AC line.
3) plug in to variac set at apx 90 V
4) turn on but DONT let the meter go above 1 amp.
If it draws over an amp its 95% HV.
If it stays on its 95% power supply.
Sometime a set wont start at 90 V. turn up a little at a time till it starts.

73 Zeno
LFOD !

The 13" models always seemed to need a 13013 regulator. I don't remember the exact number.

[zeno]

Originally Posted by dieseljeep

The 13" models always seemed to need a 13013 regulator. I don't remember the exact number.

STR30130 IIRC last 3 numbers are the voltage output.
Also came in 30110, 30120, 30123, 30125. maybe more...
Also either Samsung or Gold star had a glass diode across 2 pins that shorted.

73 Zeno
LFOD !

[Sealtest]

Originally Posted by zeno

Usually the power supply isnt regulating & triggering HV shut down ( HVSD )
Could also be over current in HV such as a bad FBT.

To diagnose safely you need a variac & AC amp meter.

1) unplug the degausser.
2) hook meter in series with AC line.
3) plug in to variac set at apx 90 V
4) turn on but DONT let the meter go above 1 amp.
If it draws over an amp its 95% HV.
If it stays on its 95% power supply.
Sometime a set wont start at 90 V. turn up a little at a time till it starts.

73 Zeno
LFOD !

I have a couple questions about this before I mess with with this set. Luckily I do have a variac and plenty of meters so this shouldn't be too bad. Anyways I am not sure how to put the meter in series with the AC line. Am I hooking the positive lead to one side of the AC line, and the Negative to the other? I am afraid of blowing the meter honestly.

Also I am a bit confused what you mean by "95%". Do you mean that it's a 95% chance that is the issue? May be a stupid question but I am trying to not miss a single detail in the instructions to ensure the right results and to avoid damaging anything.


Also not sure if this helps but this set is 19".

[Jon A.]

Originally Posted by Sealtest

I have a couple questions about this before I mess with with this set. Luckily I do have a variac and plenty of meters so this shouldn't be too bad. Anyways I am not sure how to put the meter in series with the AC line. Am I hooking the positive lead to one side of the AC line, and the Negative to the other? I am afraid of blowing the meter honestly.

Also I am a bit confused what you mean by "95%". Do you mean that it's a 95% chance that is the issue? May be a stupid question but I am trying to not miss a single detail in the instructions to ensure the right results and to avoid damaging anything.


Also not sure if this helps but this set is 19".

First make sure you're using a meter that measures amps and leave one lead at the meter end connected to common as usual; you'll probably have to move the other to the appropriate connector. That's how it works with my meter anyway, no idea if others and/or newer ones differ. As for connecting it in series with the line, one side has to be disconnected from the set somehow--the hot side will work for sure but I'm not sure of neutral--and the meter itself used to complete the circuit. I have never used the amps setting on mine, I'm yet to rig up some kind of pigtail connector I can quickly and safely plug into.

I believe you're right about the 95% probability part, I can't imagine it meaning anything else.

[zeno]

Yes 95% chance thats the area of problem.
The meter goes in series with the line. In other words
you are cutting one of the wires & inserting the meter.
Its a very common process so make up a little test jig.
If you happen to have a Sencore "Power Right" everything
is there for you, isolation, variac & metering. Great to have
but still costs $$ used due to its many uses.

73 Zeno
LFOD!

[Sealtest]

Instead of cutting the wire I will unsolder the live side and connect everything there. Eventually a test rig will be made but I just have to find all the parts around here and something to mount them in/on. I am a bit afraid of frying my meter but first I will try this with a junk meter, then move to the better meter.

I looked on the internet at those Sencore units and saw one for over $400. It sure is a nice unit though. I will keep an eye out locally for a unit like that (I've got many C-list adds looking for this stuff). Locally not too much has shown up but what has shown up gets used almost every day.

I'll update this once I get everything set up and tested. The owner would love to have this set back and I wouldn't mind the extra bench space.

[Sealtest]

Got the parts in today and have a small issue. The new 2sd1555 reads the same as the old. I have not found any bad parts in that case, so I am not sure where to look next. I think maybe a cap went bad but so far all caps are in spec.

[Sealtest]

Found a bad resistor and replaced it. I did the power up procedure and the set did not go over an amp... at first. The raster was an odd rainbow mixed with the way a screen looks when it has bad caps (caps in the power and hv section are good). The screen was slowly flashing and causing the amp meter to jump between .8 amps up to 1.1 amps with each pulse. The set also smelled like a very warm tv but it smelled stronger so I am not sure if something is dying or what. The pulsing is the main concern since it was a bit unsettling.

[Sealtest]

Disregard. It is still drawing 1.5 amps.

Here is a picture of the screen though.

I have started recapping and testing every single part but nothing is bad so far so I guess I will have to check it all again. There is an IC chip of some sorts in the HV section. Maybe that could be the problem but it is unmarked.

[zeno]

Run for about 30 sec then unpower & feel the 2SD1555.
To hot to touch most likely bad FBT or rectifier off it.
If cool or a little warm turn up variac & see if things improve.
The amps sometimes fall as the AC volts go up.
Keep in mind the HOT can short again if not careful. My advantage
doing this was knowing what I could get away with !

73 Zeno
LFOD !

[Sealtest]

Originally Posted by zeno

Run for about 30 sec then unpower & feel the 2SD1555.
To hot to touch most likely bad FBT or rectifier off it.
If cool or a little warm turn up variac & see if things improve.
The amps sometimes fall as the AC volts go up.
Keep in mind the HOT can short again if not careful. My advantage
doing this was knowing what I could get away with !

73 Zeno
LFOD !

When I stop fighting with that trinitron project I'll try this.

I'm starting to wonder if something isn't getting enough power in the set. With the Samsung at 90vAC it looks like the trinitron screen at around 50ish volts. I'd suspect caps but they've all tested good so far. Dang TVs are a challenge compared to other electronics.

[Sealtest]

Originally Posted by zeno

Run for about 30 sec then unpower & feel the 2SD1555.
To hot to touch most likely bad FBT or rectifier off it.
If cool or a little warm turn up variac & see if things improve.
The amps sometimes fall as the AC volts go up.
Keep in mind the HOT can short again if not careful. My advantage
doing this was knowing what I could get away with !

73 Zeno
LFOD !

The transistor was cool to the touch and raising the AC caused the amps to go up. Then the screen started pulsing and an odd smell filled my shop. Something is giving off heat somewhere on the board. A laser thermometer really would come in handy probably.

I'm going to look through some case histories and see if any sets in the book have had the same issue or something close.

[dieseljeep]

Originally Posted by Sealtest

The transistor was cool to the touch and raising the AC caused the amps to go up. Then the screen started pulsing and an odd smell filled my shop. Something is giving off heat somewhere on the board. A laser thermometer really would come in handy probably.

I'm going to look through some case histories and see if any sets in the book have had the same issue or something close.

Feel the electrolytics and see if the main one is getting hot or warm. They can give off a funny smell as well.
It's a good learning tool, but unfortunately it's not worth the money and effort you're putting into it.