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-   -   Received this tv for free. Can this be fixed with copper tape? (http://www.videokarma.org/showthread.php?t=271491)

queso 03-29-2019 10:37 PM

Received this tv for free. Can this be fixed with copper tape?
 
1 Attachment(s)
The owner said his son tried to switch the power cord and it just kinda looks like a botched soldering job and was wondering since the old copper came off, can I just use some 1/4" copper tape to fix this? I plan on resoldering all the dry joints and bad connections as well. Thanks for your guys' input. Also the part w/o the copper is the achot.

maxhifi 03-30-2019 12:07 AM

Quote:

Originally Posted by queso (Post 3209783)
The owner said his son tried to switch the power cord and it just kinda looks like a botched soldering job and was wondering since the old copper came off, can I just use some 1/4" copper tape to fix this? I plan on resoldering all the dry joints and bad connections as well. Thanks for your guys' input. Also the part w/o the copper is the achot.


I suggest to just fix it with wire, no need to use copper tape. The glue on the tape is unlikely to survive soldering.

queso 03-30-2019 01:46 AM

Quote:

Originally Posted by maxhifi (Post 3209785)
I suggest to just fix it with wire, no need to use copper tape. The glue on the tape is unlikely to survive soldering.

Thank you. And I know this is a very amateur question, but would I just connect the wire to the other 2 pins?

zeno 03-30-2019 04:13 PM

Yup. Tie the 3 places together with wire. Since its AC there be sure the
connections are very good.
The set was built by NAP ( North American Phillips ) A.K.A. Sylvania, Philco,
Phillips & some private brands. Watch out for cold solder around the horz
drive & output. Quite common & can burn up pretty badly.....

73 Zeno:smoke:
LFOD !

Quote:

Originally Posted by queso (Post 3209786)
Thank you. And I know this is a very amateur question, but would I just connect the wire to the other 2 pins?


queso 03-31-2019 04:48 PM

Quote:

Originally Posted by zeno (Post 3209807)
Yup. Tie the 3 places together with wire. Since its AC there be sure the
connections are very good.
The set was built by NAP ( North American Phillips ) A.K.A. Sylvania, Philco,
Phillips & some private brands. Watch out for cold solder around the horz
drive & output. Quite common & can burn up pretty badly.....

73 Zeno:smoke:
LFOD !

Thanks for the information! I have a lot to learn! Could you tell me what this thing is? Is it a capacitor?
https://i.imgur.com/GwnqHZn.jpg

Dude111 04-01-2019 03:29 AM

Good luck buddy :)

Notimetolooz 04-01-2019 09:45 AM

Quote:

Originally Posted by queso (Post 3209828)
Could you tell me what this thing is? Is it a capacitor?
https://i.imgur.com/GwnqHZn.jpg

Yes that is a capacitor used to filter out noise on the input power line as well as prevent signals exiting the TV. That probably would not be a paper capacitor so it is fine and does not need to be replaced.

queso 04-01-2019 05:28 PM

I ended up isolating the capacitor and, although I don't have something to measure capacitance, there is no resistance whatsoever so I'm assuming it's dead. I got my hands on the schematic and it's .22uf. Gonna be replacing that to see how it goes. Thanks for all of your help.

The capacitor is right next to the fuse and ac connectors so I'm assuming the soldering iron may have gotten too hot and messed it up.

Electronic M 04-01-2019 05:55 PM

Quote:

Originally Posted by queso (Post 3209866)
I ended up isolating the capacitor and, although I don't have something to measure capacitance, there is no resistance whatsoever so I'm assuming it's dead. I got my hands on the schematic and it's .22uf. Gonna be replacing that to see how it goes. Thanks for all of your help.

The capacitor is right next to the fuse and ac connectors so I'm assuming the soldering iron may have gotten too hot and messed it up.

Capacitors are NOT supposed to have resistance...Some electrolytic capacitors will briefly measure as having resistance due to requiring enough charging current for a DMM in ohms mode to detect*, or reverse polarity leakage, but all other capacitor types SHOULD measure open circuit (unless they have failed shorted).

*DMMs measure resistance by applying a voltage, measuring current draw and computing resistance based on current and voltage.

queso 04-01-2019 06:12 PM

Quote:

Originally Posted by Electronic M (Post 3209869)
Capacitors are NOT supposed to have resistance...Some electrolytic capacitors will briefly measure as having resistance due to requiring enough charging current for a DMM in ohms mode to detect*, or reverse polarity leakage, but all other capacitor types SHOULD measure open circuit (unless they have failed shorted).

*DMMs measure resistance by applying a voltage, measuring current draw and computing resistance based on current and voltage.

Looks like I'm going to have to invest in something to measure the capacitance...For now I'll see if someone has one I can borrow. Which do you recommend?
Also, if it is confirmed dead, does the size/lead distance of a replacement matter if the uf/v is the same?

Electronic M 04-01-2019 07:41 PM

Quote:

Originally Posted by queso (Post 3209873)
Looks like I'm going to have to invest in something to measure the capacitance...For now I'll see if someone has one I can borrow. Which do you recommend?
Also, if it is confirmed dead, does the size/lead distance of a replacement matter if the uf/v is the same?

First of all the AC line interference filter cap is a almost totally useless part...You can literally clip one out of nearly any working set (or other devices power supply) that uses one and the set will keep working without it with NO noticeable difference in performance...It may as well be called an appendix capacitor.

Capacitor tester depends on your needs. For solid stat gear I reccommend one of these ...https://www.ebay.com/itm/All-in-1-LC...RSbR68buZCZFOw There are hundreds of them on ebay under a search for "ESR tester" pick your price point, vendor, and their home country (unless you live in china or hong kong buying one from a seller there is going to increase your wait).
If you need to test lytics to working voltages of 50V or higher get a Heathkit C3 (like mine) or some other eye tube based tester.

If you replace a line rated cap size don't matter much as long as the leads reach, BUT on top of the capacitance and voltage you need an X or Y rated line cap to go across the powerline otherwise the AC may ruin your replacement.

Notimetolooz 04-02-2019 09:58 AM

I wouldn't go looking for problems when there is no evidence that there is one. Just by the look of the circuit board this set doesn't look very old. If it was made after about 1980 there wouldn't be any reason for whole sale part replacement. Does it have tubes? Since you probably don't have a metered variac or dim-bulb tester, after you fix the obvious solder problem just power it up and try it.

queso 04-02-2019 07:36 PM

The capacitor was in fact dead after testing it with a friend. After looking at it a bit more, some of the plastic had melted off of it and I'm assuming onto the soldering gun/iron. I'm sure that had something to do with it. I'll probably just order a similar replacement one on eBay along with that all in one LCR. I have watched several reviews and it looks nice for the price. Thanks for the recommendation.

There was absolutely nothing wrong with the picture or color when it worked. The reason they gave it away was because about once an hour when randomly watching, the TV would entirely power off and back on immediately as if nothing happened. The cord was being replaced because it was almost entirely green throughout with oxidation.


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