Working on a Tc-p50s30

[ricosavy]

I have a shorted s1172b regulator 3.3 output it is a hsop 6 smd.I am looking for a replacement since you have to order 2000 to get it.I found one but not sure it it will work part number s-1142b33l-e6t1u this one I can order one for $1.52.Any input would be appreciated.thanks

[ricosavy]

Re: Working on a Tc-p50s30

Here the one that is bad

[ricosavy]

Re: Working on a Tc-p50s30

Here is the pic of replacement part

[tw2005]

Re: Working on a Tc-p50s30

I don't know but you could just get it from Sears IC8702 , C0DBAFG00029

http://www.searspartsdirect.com/part.../0057/528.html

[tw2005]

Re: Working on a Tc-p50s30

IC8702 in cct diagram suggests it's a 1.8V?

[tw2005]

Re: Working on a Tc-p50s30

1.85 V ±1.0% S-1172B1J-U5T1x (sot89), S-1172B1J-E6T1x (hsop)

Have I got the right chip in the photo? do you see the 1J on the 2nd line of that chip?

[ricosavy]

Re: Working on a Tc-p50s30

I thought it was a 3.3v let me check

[ricosavy]

Re: Working on a Tc-p50s30

Yes it is ic8702

[ricosavy]

Re: Working on a Tc-p50s30

Well pulled the chip to make sure it was shorted and outside it is not.something else is shorting out the chip

[ricosavy]

Re: Working on a Tc-p50s30

When i check for resistance from pin 6 or 3 to ground i get less than 1 ohm.also when i check pin 6 and 3 to pin 2 or 5 there is resistance.since pin 2 and 5 are ground.at first i thought that ic was bad but when i pulled and did same tests no resistance between pins and ground on the chip by it self.but on the pins with no chips the readings show short between pin 3 and 6 to ground.I am thinking bad caps.here is the schematic of the chip.it is not very clear but that is all i could find

[dick_barton]

Re: Working on a Tc-p50s30

Datasheet

[ricosavy]

Re: Working on a Tc-p50s30

I removed the caps and like to be expected Panasonics caps usually don't go bad still have short.i traced the shorted line looks like it is going ic 8000.If that is bad this board is going into the I don't have equipment to replace it box.When I get ird bga machine then I will put back on the work bench.

[ricosavy]

Re: Working on a Tc-p50s30

Here pic of chip.

[tw2005]

Re: Working on a Tc-p50s30

I removed the caps and like to be expected Panasonics caps usually don't go bad still have short.i traced the shorted line looks like it is going ic 8000.If that is bad this board is going into the I don't have equipment to replace it box.When I get ird bga machine then I will put back on the work bench.

yeah, I was thinking you may be heading that way when you said this was shorted. I think a few have tried tracing these when dead and the supply side ends up ok only to find the chip being supplied is fried.

[mattstolte]

Re: Working on a Tc-p50s30

What blink code was your tv giving off with this short

[ricosavy]

Re: Working on a Tc-p50s30

I was hoping it would be simple fix but some how i knew it would end up there.maybe one day i will invest in a tool to remove these.What would you recommend.

[ricosavy]

Re: Working on a Tc-p50s30

I was hoping it would be simple fix but some how i knew it would end up there.maybe one day i will invest in a tool to remove these.What would you recommend.

[ricosavy]

Re: Working on a Tc-p50s30

14 blink

[tw2005]

Re: Working on a Tc-p50s30

14 blink

Interesting, a real 14 blink. Shorted Sc can cause 14 blink too

[ricosavy]

Re: Working on a Tc-p50s30

It is the main board .100 percent sc is good.