Samtron CRT Monitor. Power LED Blink

[nish_pinto]

I have a Samtron 15" CRT Monitor in workshop. It belongs to my friend.

Problem: Green Led light keeps blinking and I can hear a clicking sound. Does any one know what the problem might be? He said it has been repaired before because of the same problem. I have never worked on CRTs before. So I need expert opinions on what could be the cause. Here are the pictures of the PCB.

[goodpsusearch]

Re: Samtron CRT Monitor. Power LED Blink

That Capxon! Is it a previous repair?

[tom66]

Re: Samtron CRT Monitor. Power LED Blink

Samsung use Capxon in their products, too... had a 32 inch LCD TV with them.

[ben7]

Re: Samtron CRT Monitor. Power LED Blink

LOL, if that capxon was for the 'repair', it was put there to make the relay delay longer :P

I suggest that you test the power rails for shorts. Also, check the big transistor on the heatsink near the flyback for shorts.

[nish_pinto]

Re: Samtron CRT Monitor. Power LED Blink

That Capxon! Is it a previous repair?

I am not sure about that.

[nish_pinto]

Re: Samtron CRT Monitor. Power LED Blink

LOL, if that capxon was for the 'repair', it was put there to make the relay delay longer :P

I suggest that you test the power rails for shorts. Also, check the big transistor on the heatsink near the flyback for shorts.

Delay longer? sorry, what does that mean?

And I hear a clicking sound, what could that indicate?

[ben7]

Re: Samtron CRT Monitor. Power LED Blink

Delay longer? sorry, what does that mean?

The relay is usually used to turn the degaussing coil on and off. The capacitor is used to provide a time delay.

[nish_pinto]

Re: Samtron CRT Monitor. Power LED Blink

Thanks for the quick reply. Anything else I should look closely on? Should I try replacing that capxon?

[ben7]

Re: Samtron CRT Monitor. Power LED Blink

Thanks for the quick reply. Anything else I should look closely on? Should I try replacing that capxon?

Look for burned areas, capacitors leaking from the top or bottom, broken/cracked solder points.

[kc8adu]

Re: Samtron CRT Monitor. Power LED Blink

firstly if that thing has a blue label samsung crt just junk it now unless this is a practice repair.these were all going to air in the first year.guess what your chances of a good one now are?

[kc8adu]

Re: Samtron CRT Monitor. Power LED Blink

and the hot is shorted causing the blink/click.

[ben7]

Re: Samtron CRT Monitor. Power LED Blink

and the hot is shorted causing the blink/click.

How do you know? Maybe that is not the problem...

[nish_pinto]

Re: Samtron CRT Monitor. Power LED Blink

and the hot is shorted causing the blink/click.

whats that?

[ben7]

Re: Samtron CRT Monitor. Power LED Blink

whats that?

In CRT repair terms, HOT means Horizontal Output Transistor.

[nish_pinto]

Re: Samtron CRT Monitor. Power LED Blink

Damn, I am noob here. How to check if it is short using a multimeter?

[nish_pinto]

Re: Samtron CRT Monitor. Power LED Blink

No burns, No bloated/leaking caps. Everything looks fine on the board.

[ben7]

Re: Samtron CRT Monitor. Power LED Blink

No burns, No bloated/leaking caps. Everything looks fine on the board.

Measure the voltages on the power rails.

What is the part number of the HOT? (the BIG 3-leg plastic case transistor by on the heatsink next to the flyback transformer)

[kc8adu]

Re: Samtron CRT Monitor. Power LED Blink

its called seeing several hundred busted units.
this thing is good for practice fodder.nothing else.
the gassy crt trashes the hot when it arcs.

How do you know? Maybe that is not the problem...