Sansui SV-2615 LCD

[burntfingers]

This set cuts off the screen, sound remains OK on that station but doesn't change to other stations.
Needs to switch off and on again to bring picture [perfect picture].
Takes longer to shut screen when it's cold, and less and less as it warms up.

I checked the power board for d/js and used a computer fan to extract heat, to no avail.

[burntfingers]

Re: Sansui SV-2615 LCD

Could it be the inverter circuit?
Do I need to replace the whole PS board?

[Dgtech]

Re: Sansui SV-2615 LCD

I have seen this board in multiple sets now. This power board can be found in Polaroid, Memorex, Element. It may help to investigate more by searching Polaroid threads here on this site. Here are just a couple:

https://www.badcaps.net/forum/showthread.php?t=12886

https://www.badcaps.net/forum/showthread.php?t=10017

[burntfingers]

Re: Sansui SV-2615 LCD

I have seen this board in multiple sets now. This power board can be found in Polaroid, Memorex, Element. It may help to investigate more by searching Polaroid threads here on this site. Here are just a couple:

https://www.badcaps.net/forum/showthread.php?t=12886

https://www.badcaps.net/forum/showthread.php?t=10017

Thank you.

The set is right now holding its picture, since I connected a computer fan, as you see in the picture.
There is a small cap nearby, but maybe the culprit is the chip - assuming the fan has located the problem area.

[dumpystig]

Re: Sansui SV-2615 LCD

I had a lot of probs on a recent project with dry joints, particularly around the Microprocessor on the Mainboard - the M/p ran quite hot and I found several SMD components below/adjacent to it needed to be re-flowed. I also installed a 50mm PC case fan on the TV back cover directly above the M/p which keeps the temp much lower and the set runs fine now.

[burntfingers]

Re: Sansui SV-2615 LCD

I had a lot of probs on a recent project with dry joints, particularly around the Microprocessor on the Mainboard - the M/p ran quite hot and I found several SMD components below/adjacent to it needed to be re-flowed. I also installed a 50mm PC case fan on the TV back cover directly above the M/p which keeps the temp much lower and the set runs fine now.

While blowing air on the IC, it's holding picture!

[burntfingers]

Re: Sansui SV-2615 LCD

While blowing air on the IC, it's holding picture!

This inverter IC could be the culprit, after all.
I haven't got one at the moment.
Just sent an email to Mastercare Sparescare, here in Johannesburg to see if they stock it.
I have told the customer that the set is holding nicely while the fan is going - a low noise one, by the way.

[dumpystig]

Re: Sansui SV-2615 LCD

Looks like it's in a DIL socket too, should be a simple replacement

[lti]

Re: Sansui SV-2615 LCD

That appears to be a microcontroller. It may have a custom program stored in internal ROM, so a new chip might not work. It is strange that the chip is socketed.

This is the first time I have seen a Sansui TV that wasn't a CRT.

[Dgtech]

Re: Sansui SV-2615 LCD

Did you physically feel this chip heating up?? Chips like these usually dont. The chip to the right of it is the PWM. I'm about to change one out in a board that I have. Does that Red LED on the left bottom corner of the power board ever turn on?

[burntfingers]

Re: Sansui SV-2615 LCD

Did you physically feel this chip heating up?? Chips like these usually dont. The chip to the right of it is the PWM. I'm about to change one out in a board that I have. Does that Red LED on the left bottom corner of the power board ever turn on?

Yes, when the screen turns black, the LED goes on/off at slow time.

The IC wasn't hot at all, nor could I detect an increase in temperature prior to the fault showing up.

[Dgtech]

Re: Sansui SV-2615 LCD

This sounds similar to a problem I am having with one set.

Here is the thread with my set's failure:

https://www.badcaps.net/forum/showthread.php?t=13573

I got to find out what that LED is telling me. It's some type of diagnostic.

[burntfingers]

Re: Sansui SV-2615 LCD

This sounds similar to a problem I am having with one set.

Here is the thread with my set's failure:

https://www.badcaps.net/forum/showthread.php?t=13573

I got to find out what that LED is telling me. It's some type of diagnostic.

I will be interested to know.
To me, the flickering LED meant no power going through the inverters.

By the way, I'm trying to get the faulty IC, but it's looking hard.

The boards are "Made in China" - stamped on them - and this particular set will not last very long, I'm sure!

I had to scrap two other set recently, because of no spares available!

[Dgtech]

Re: Sansui SV-2615 LCD

Sometimes you can get more money for the parts than the whole set.

[Sir farts alot]

Re: Sansui SV-2615 LCD

Hi There did you Check on dry joints on the IC ? Sometimes loose dry joints could be the cause of similar problems

[burntfingers]

Re: Sansui SV-2615 LCD

Hi There did you Check on dry joints on the IC ? Sometimes loose dry joints could be the cause of similar problems

Yes, I did.
That's basic, standard procedure.
I remove the IC from socket twice.
It has definitely to do with internal situation.
Anyway, the customer accepted a fan and took the set.
I had it working fine for 9 hours, so I imagine it will hold for a few months.
Besides, picture quality wasn't top anymore.
These sets do not help you to become popular...