Samsung 193v 2sec-black issue

[Solder Boy]

Got this from a client of mine last week, thought it was going to be an easy fix.. guess I was wrong..

It was made in 2003 so I kinda suspect that after 8 years perhaps the lamps are indeed kaput because when I cracked it open, there were no obvious bad caps.

But I did check all of the caps with ESR meter. All of the tall skinny ones were indeed bad as usual so they got replaced. I resoldered the pins of the transformer. Put it back together somewhat, turned it on still not working right.

The filter cap read 1 instead of 0.. is this a possible issue?

After I did some research here I think I goofed while doing the CCFL test.. I left the 3 other sockets empty and just used a single spare lamp.

Wanted to rule out everything else before I really tear this thing apart to get at the lamps.

Additional Info.. I plugged in a pair of spare lamps that are known to be good and I still get the 2second to black issue. I noticed that the lamps didn't come on right away.. took a bit of time for them to light up.. ( maybe 10 seconds if that).. scratching head now..
See attached pics..

[alexanna]

Re: Samsung 193v 2sec-black issue

I have had mixed results testing with just one lamp plugged in ,I have even had monitors where the single lamp would light but it was still causing a sec to black problem.
The best way to test in my opinion, would be to use at least on good ccfl.
Al
well I mised the part where you used known good lamps Sorry.

[PlainBill]

Re: Samsung 193v 2sec-black issue

You will need lamps connected to all four connectors or you will get 'two seconds to black'.

PlainBill

[alexanna]

Re: Samsung 193v 2sec-black issue

You will need lamps connected to all four connectors or you will get 'two seconds to black'.

PlainBill

Well I guess I get a Mark Twain on that one.
What I thought the OP was describing was a way to find a totally failed ccfl.
Al

[Solder Boy]

Re: Samsung 193v 2sec-black issue

You will need lamps connected to all four connectors or you will get 'two seconds to black'.

PlainBill

Hi Bill.. guess I should have clarified. I installed 2 pairs of lamps so all 4 sockets were connected.. still had the 2 second to black issue.

What I meant and how it came out were two different things..

[PlainBill]

Re: Samsung 193v 2sec-black issue

Well I guess I get a Mark Twain on that one.
What I thought the OP was describing was a way to find a totally failed ccfl.
Al

One thing that complicates the process is many monitors use a single secondary to drive two CCFLs. A single CCFL won't light with that design, you will need two.

PlainBill

[PlainBill]

Re: Samsung 193v 2sec-black issue

Hi Bill.. guess I should have clarified. I installed 2 pairs of lamps so all 4 sockets were connected.. still had the 2 second to black issue.

What I meant and how it came out were two different things..

Thanks for clarifying that. Did all four CCFLs light up?

PlainBill

[Solder Boy]

Re: Samsung 193v 2sec-black issue

Thanks for clarifying that. Did all four CCFLs light up?

PlainBill

Yes the spare lamps did light up.. although it wasn't right away.. my understanding is that they are supposed to light up immediately. It took them more than a few seconds. Is this normal?

[PlainBill]

Re: Samsung 193v 2sec-black issue

Yes the spare lamps did light up.. although it wasn't right away.. my understanding is that they are supposed to light up immediately. It took them more than a few seconds. Is this normal?

Not only is it not normal, it is very unusual. We all know the variable nature of time (five seconds being kissed by Aunt Edna seems a lot longer than 5 seconds being kissed by third cousin Sally). I'd suggest you time the actual delay. I could accept a 1 or 2 second delay; longer indicates a problem.

PlainBill

[Solder Boy]

Re: Samsung 193v 2sec-black issue

Okie dokie I will do that sometime today when I get a chance.