View Full Version : i screwed up and need help identifying this part.


technicolor
05-29-2013, 02:26 PM
Ok, I screwed up on this big time. On my other maggie chassis (number unknown) but resembles a 933/931, I replaced that peanut shape thing, thinking it was a 68uh 5 amp line choke. I don't know what i was doing, but now i cannot find any where in my sams photofact, where the reference was that i saw that it was a line choke.


after recapping the set, it is showing signs of life (i have high voltage now) but it has issues. I am now fairly certain i put in the wrong part, and it is not a 68uh line choke.

here's a pic, it' the peanut shape thing, it's attached to the terminal strip and it has four legs.

http://paintforcars.com/Merchant2/images/!CID__Photo05291503_1.jpg

Here's the sams photofact for a 931 chassis, it has the identical part.

http://paintforcars.com/Merchant2/images/0984_1n.pdf


Can i get some educated guesses here from the experts, radiotvphononut u got any ideas?

and if somebody has a parts chassis lying around, i'll gladly throw u a few dollars for this.

VintagePC
05-29-2013, 03:07 PM
Looks to me like some of the parts I've seen in my set which is a resistor with a coil of some sort wound around it?

Sorry I can't be of more help, but that might help you find it on the schematic and/or parts list.

wa2ise
05-29-2013, 03:33 PM
Find an old CRT computer monitor or PC power supply. They usually have line chokes. two windings on one core. They don't look like peanuts but do the same function, namely blocking high frequency crud getting in or out of the set. Salvage one and use it, just be sure you don't short across the line with it. The inductance value is not critical. If you're getting full line voltage thru your existing coil, I wouldn't worry about it.

technicolor
05-29-2013, 03:34 PM
Find an old CRT computer monitor or PC power supply. They usually have line chokes. two windings on one core. They don't look like peanuts but do the same function, namely blocking high frequency crud getting in or out of the set. Salvage one and use it, just be sure you don't short across the line with it. The inductance value is not critical. If you're getting full line voltage thru your existing coil, I wouldn't worry about it.

but that's the question, that peanut shape thing, u think it is a line choke?

Zenith26kc20
05-29-2013, 03:53 PM
yes, it is a dual winding line choke. Some are not encapsulated like that one. Most sets use that to keep interference from their switch mode power supplies from getting into the line and to prevent (somewhat) noise from entering the set from the line. There is also a capacitor after the choke.

technicolor
05-29-2013, 04:02 PM
yes, it is a dual winding line choke. Some are not encapsulated like that one. Most sets use that to keep interference from their switch mode power supplies from getting into the line and to prevent (somewhat) noise from entering the set from the line. There is also a capacitor after the choke.

maybe i'm not crazy after all. I seem to recall seeing somewhere in the photofac it was a 65uh. Then i replaced with a 5 amp 68uh.

Now this just arrrived in the mail

http://www.ebay.com/itm/290718131729?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

is there a difference betweeen a line choke and a rf choke?


Thanks for all the answers

Username1
05-29-2013, 05:44 PM
The ones you got on ebay are not the same. Those are not for tv current, just signal current. 1000Ma is just 1 amp. Your replacement would need to handle surge current when it powers up. Plus should be 20% min above whatever is posted on the back of the set.

If it were me, I would not use the ebay one to replace the one in the tv, ratings seem low to me.

After looking at the sam's its a tube set, 300+ watts, those little choke's will burn out like a slow blow fuse.

technicolor
05-29-2013, 05:58 PM
The ones you got on ebay are not the same. Those are not for tv current, just signal current. 1000Ma is just 1 amp. Your replacement would need to handle surge current when it powers up. Plus should be 20% min above whatever is posted on the back of the set.

If it were me, I would not use the ebay one to replace the one in the tv, ratings seem low to me.

Hey squirrel boy, thanks for the reply. what i have in there now is this:
http://www.ebay.com/itm/180681897620?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

I thought these were letting in too many amps and this is why maybe i was having problems.

what do u think?

Username1
05-29-2013, 06:00 PM
5A is well within a good safety margin.

Username1
05-29-2013, 06:03 PM
just be sure you wire them right, you're going to single's from a 4 wire item. put them in just like in the circuit, don't get confused looking at how they are wired on that tie point thing...

I don't think I have ever run across bad line filters.... Why are you changing them?

technicolor
05-29-2013, 06:17 PM
just be sure you wire them right, you're going to single's from a 4 wire item. put them in just like in the circuit, don't get confused looking at how they are wired on that tie point thing...

I don't think I have ever run across bad line filters.... Why are you changing them?

Hot wax dripped on the original and kind of melted and deformed the coating, i assumed it was bad.

Your on to something though, maybe i wired it in wrong. If i post better pics tomorrow of the two sets, could u take a look at it and check it?

also, u lost me, what tie point thing?

Username1
05-29-2013, 06:23 PM
Sorry the picture is not too focused, I can't tell if its on a pc board, or on some solder lugs. If you put it in wrong, you may end up shorting the plug, then fire explosions, your house on the late news. Use a ohm meter with the set unplugged, trace the wires directly from the interconnect to the choke, and then on to the next point.

Username1
05-29-2013, 06:31 PM
See the path of the power through the choke. Be sure when you replace the 4 wire item with the 2 wire items, the power still follows the same path. If you accidentally wire it across the 2 power in lines, sparks will fly. Just be careful.

Electronic M
05-30-2013, 02:05 AM
I think the single part version takes advantage of the common core to preform additional noise canceling.

I'd check and reinstall the original if good.

As a general rule I never replace anything other than tubes and caps without testing unless the part is obviously destroyed beyond doubt.

I usually test tubes and caps if not paper type to keep from wasting money on replacing parts that still have life left....Yea, I'm a cheap SOB.

Username1
05-30-2013, 04:47 AM
I agree...

Only for one thing... When I took tv repair in BOCES our instructor had on his desk a electrolytic can that had taken off like a rocket from the tv chassis, blasted to the top of the cabinet and accordion-d the top of the can about 1 inch. Floor model tv. So I think if yer gunna leave in the can's you should check em now and then for temperature see if they're gettin warm...