Black screen! Oh no!

[Jeffhs]

Those Polaroid branded HDTVs are not the best sets in the world, or so I gather from what I've read about them online. If yours is going to need more than a new inverter board, I'd just replace the entire set. I'm not sure if individual modules are repairable at the component level or not, but I'd guess not, considering they have surface-mount components and are wave-soldered by machine at the factory. That these TVs are not made by a known manufacturer (most aren't, unfortunately) is not a factor in your favor either. I don't know how big your set is, but if it's much less than 32 inches or so I'd junk it. Smaller screen HDTVs are just not worth repairing, as the cost of repairs (added to that of the initial diagnosis) can and all too often does exceed the price of a new set.

[Geoff Bourquin]

Take a close look at the little blue ceramic capacitors next to the transformers. I have seen those go. They usually darken when they fail. (Sometimes they darken to the point of being crumbly black soot!) I wouldn't be surprised if one has shorted. Should be around 22pf/6kv IIRC. I usually get them from Mouser.

[John James]

Originally Posted by Jeffhs

Those Polaroid branded HDTVs are not the best sets in the world, or so I gather from what I've read about them online. If yours is going to need more than a new inverter board, I'd just replace the entire set. I'm not sure if individual modules are repairable at the component level or not, but I'd guess not, considering they have surface-mount components and are wave-soldered by machine at the factory. That these TVs are not made by a known manufacturer (most aren't, unfortunately) is not a factor in your favor either. I don't know how big your set is, but if it's much less than 32 inches or so I'd junk it. Smaller screen HDTVs are just not worth repairing, as the cost of repairs (added to that of the initial diagnosis) can and all too often does exceed the price of a new set.

My set is 40". I found the board I think I need online for approx. $70.00. It would cost about 10 times that to replace the set.

Thanks for taking the time to reply though.

[John James]

Originally Posted by Geoff Bourquin

Take a close look at the little blue ceramic capacitors next to the transformers. I have seen those go. They usually darken when they fail. (Sometimes they darken to the point of being crumbly black soot!) I wouldn't be surprised if one has shorted. Should be around 22pf/6kv IIRC. I usually get them from Mouser.

They look fine from the outside (but what do I know?) I found the whole board online so I think I may go that way. From what I could tell, the frying sound seems to be coming from one of the transformers. Does that sound reasonable to you?
Is it possible for me to test either the caps or the transformers while they are still attached to the board? The board is out of the set now.

[Zenith26kc20]

Sorry, didn't mean to upset you about the Polaroid. I have a 20 inch early one myself I use around the shop. It does give a good picture on VGA input. It has analog only tuner. I guess I get too many customers who have trouble using their Polaroids and it has kinda turned me against them. As I said, I ususlly run into capacitors bad. I have had a few with the harness going to the screen oxidzing and needing a cleaning too.

[John James]

Originally Posted by Zenith26kc20

Sorry, didn't mean to upset you about the Polaroid. I have a 20 inch early one myself I use around the shop. It does give a good picture on VGA input. It has analog only tuner. I guess I get too many customers who have trouble using their Polaroids and it has kinda turned me against them. As I said, I ususlly run into capacitors bad. I have had a few with the harness going to the screen oxidzing and needing a cleaning too.

Hey, you didn't upset me! I appreciate any and all comments. All I know about electronics could be put on a postcard, so anything someone wishes to contribute is more than welcome.

As far as my trouble goes, I have ordered a complete power supply board. It should be here later this week. I'll put it in and report back.

Again, thanks to everyone for their replies,

John

[John James]

Got the new power supply board in this afternoon and.... I'm back in business!

Thanks to everybody that responded.



(Took offer down. Probably not the right place for it.)