Curtis lcd3215a Standby power only

[allsmith]

Re: Curtis lcd3215a Standby power only

Not sure if you have already changed/checked these components or not.

I have tested the diode you pointed out.
Auto range meter on diode test in circuit.
Diode=
positive to bar= .49
negative to bar= OL

The resister you pointed out R29
Auto range meter set to ohms.In circuit.
=73.8
Reverse=72.5

I dont know how to test the ceramic or film cap that is with the diode and resistor

I have not changed any of the small electrolytic caps,only the two bigger ones that where slightly puffed.(pic in my first post)

Could i replace the small electrolyic caps that you pointed out with some caps from a couple computer power supplies that i have? As long as the capacitance and voltage are the same? Just for testing,then i'll order new ones,if i get it working.

Thanks!

[budm]

Re: Curtis lcd3215a Standby power only

The Diode is OK, yes change that start up cap first with what you have just to test it as long as you know that the replacement cap is good, that is the catch.
By the way, were you able to test the pin7 VCC pin of the IC?

[allsmith]

Re: Curtis lcd3215a Standby power only

The Diode is OK, yes change that start up cap first with what you have just to test it as long as you know that the replacement cap is good, that is the catch.
By the way, were you able to test the pin7 VCC pin of the IC?

Ok thanks i'll look and see if i can find a different start up cap.

I have not tested pin 7 for VCC yet, I think Tom was gonna have me solder a wire to it so i can set the board back in tv and still be able to test pin 7.

Could i connect the board to ground with a wire and stand up the power supply secured and propped up by a roll of paper towels or something like that and power supply connections all plugged in to test pin 7?

[budm]

Re: Curtis lcd3215a Standby power only

That will be very dangerous sine the section you are checking is in the primary hot side of the circuit which can be deadly, I rather have you solder the wire to pin7 as suggested by Tom or the positive pin of that start up cap, that positive pin of that cap should have a trace connected directly to pin7 of that IC, please verify that by using an Ohm meter, it should show less than 1 Ohm. The Ground test point for your meter to test this primary side will be the negative leg of the large Main DC filter cap (not the chassis ground).

[retiredcaps]

Re: Curtis lcd3215a Standby power only

That will be very dangerous sine the section you are checking is in the primary hot side of the circuit which can be deadly,

Yep. There is almost 400V DC there.

[allsmith]

Re: Curtis lcd3215a Standby power only

The Diode is OK, yes change that start up cap first with what you have just to test it as long as you know that the replacement cap is good, that is the catch.
By the way, were you able to test the pin7 VCC pin of the IC?

Good call on the start up cap man!!

I just replaced the the teapo 33uf 25v start up cap with a rubycon 33uf 50v 105 degree from a cable box power supply..SHE LIT RIGHT UP!!!Got a bright blue screen!!!! Haven't tested any farther than seeing the screen light up yet though.

Do you recommend the capacitor kits you can find online that has all electrolitics that are needed for the power supply for your tv's model?
There appears to be about 10 caps in a kit(model depending im sure) and quality brands.Around 16 dollars for a kit.

Or are you better off sizing them all yourself and ordering that way?

Man!! I can't thank you and everbody else here that has helped me out enough!!
Its very much appreciated!!!

[retiredcaps]

Re: Curtis lcd3215a Standby power only

Do you recommend the capacitor kits you can find online that has all electrolitics that are needed for the power supply for your tv's model?

Or are you better off sizing them all yourself and ordering that way?

The latter via digikey.com or mouser.com. The latter is about 50% cheaper and you are guaranteed to get the correct caps. Some sellers miss one or don't include a couple here/there.

[retiredcaps]

Re: Curtis lcd3215a Standby power only

With DIY cap picking, see this guide

https://www.badcaps.net/forum/showpo...84&postcount=3

[budm]

Re: Curtis lcd3215a Standby power only

I use Digikey due to USPS shipping of around $2.50 for small order. I use FM/FR/FC series. Make sure to replace the other small one I redlined. Glad to hear it is working.

[allsmith]

Re: Curtis lcd3215a Standby power only

That will be very dangerous sine the section you are checking is in the primary hot side of the circuit which can be deadly, I rather have you solder the wire to pin7 as suggested by Tom or the positive pin of that start up cap, that positive pin of that cap should have a trace connected directly to pin7 of that IC, please verify that by using an Ohm meter, it should show less than 1 Ohm. The Ground test point for your meter to test this primary side will be the negative leg of the large Main DC filter cap (not the chassis ground).

Good advice!!Ive been very cautious when i've been testing in these things!! But will be even more cautious now!!!

I just bought a new DMM today thats cat3,65 dollar amprobe,Not sure if its a very great meter but its got to be better than the 8 dollar cheapy that i was using!!

After testing that 400v cap with that cheap meter and could see tiny blue arcs on the probs i knew right then that i wanted a better meter!!

Thanks for your advise!

[allsmith]

Re: Curtis lcd3215a Standby power only

The latter via digikey.com or mouser.com. The latter is about 50% cheaper and you are guaranteed to get the correct caps. Some sellers miss one or don't include a couple here/there.

Sounds good! I'll go that route.

Thanks for your help!! Much appreciated!!

[budm]

Re: Curtis lcd3215a Standby power only

I always have what ever I work on plugged into GFI outlet (you can easily build one for around $20 using the electrical box, GFCI outlet, power cord from old electronics equipment) at least to protect myself beside using the isolation transformer. Your life is worth at least $20. And if you get real serious you may want to make a box that will put what you are working on in series with the lamp that will light up bright if you have short circuits instead of keep blowing the fuse until you find the short.
http://s807.photobucket.com/albums/yy352/budm/Tools/

[allsmith]

Re: Curtis lcd3215a Standby power only

I use Digikey due to USPS shipping of around $2.50 for small order. I use FM/FR/FC series. Make sure to replace the other small one I redlined. Glad to hear it is working.

Thanks!! I'll replace them all,especially since just one little one is all it takes!!

[retiredcaps]

Re: Curtis lcd3215a Standby power only

I just bought a new DMM today thats cat3,65 dollar amprobe,Not sure if its a very great meter but its got to be better than the 8 dollar cheapy that i was using!!

For one retiredcaps' bonus point, post a picture of the new Amprobe. I have 2 Meterman multimeters. Meterman was eventually bought by Amprobe and Amprobe just name rebadged a lot of their models.

[allsmith]

Re: Curtis lcd3215a Standby power only

I always have what ever I work on plugged into GFI outlet (you can easily build one for around $20 using the electrical box, GFCI outlet, power cord from old electronics equipment) at least to protect myself beside using the isolation transformer. Your life is worth at least $20. And if you get real serious you may want to make a box that will put what you are working on in series with the lamp that will light up bright if you have short circuits instead of keep blowing the fuse until you find the short.
http://s807.photobucket.com/albums/yy352/budm/Tools/

I like the GFCI idea ,i'll get right on that!
Will that give you a second chance in an accident?But still be nasty?

Ive been wanting to make a dim bulb tester for the vintage audio recievers i've been working on,Getting ready to replace my first shorted output transistor on a practice intergrated amplifier.

Can i ask what a isolation transformer is?

[allsmith]

Re: Curtis lcd3215a Standby power only

For one retiredcaps' bonus point, post a picture of the new Amprobe. I have 2 Meterman multimeters. Meterman was eventually bought by Amprobe and Amprobe just name rebadged a lot of their models.

Here she is,

They sell them at lowes,my local home improvement center.

Is it a decent meter?

[budm]

Re: Curtis lcd3215a Standby power only

The isolation transformer is a 1:1 (120v in 120 volt out), the output side is completely isolated from the primary hot side, only ground connection is common to both side.
All my receivers/power amps/ pre-amp (Pioneer, Sansui, Yamaha, SAE, etc) are from the 70 and early 80, they were built like a tank. The lamp setup will save you so many new output transistors from blowing up since direct couple circuits can easily take out the whole chain of transistors when on goes bad.
http://en.wikipedia.org/wiki/Isolation_transformer

[allsmith]

Re: Curtis lcd3215a Standby power only

The isolation transformer is a 1:1 (120v in 120 volt out), the output side is completely isolated from the primary hot side, only ground connection is common to both side.
All my receivers/power amps/ pre-amp (Pioneer, Sansui, Yamaha, SAE, etc) are from the 70 and early 80, they were built like a tank. The lamp setup will save you so many new output transistors from blowing up since direct couple circuits can easily take out the whole chain of transistors when on goes bad.
http://en.wikipedia.org/wiki/Isolation_transformer

Nice! i like vintage audio!!I have a yamaha r-8 that i bought new in 1985,and just picked up the r-9 Class A the other day.Also got a 1981 150 wpc fisher the other day for 50 buck!!Also some 1985 ADS speakers,man these things sound good!!

[retiredcaps]

Re: Curtis lcd3215a Standby power only

They sell them at lowes,my local home improvement center.

Is it a decent meter?

One retiredcaps' bonus point for you.

I totally forgot I had an Amprobe AM-60. I got mine off ebay. When I had it, I liked most things about. I eventually sold it because I got a Fluke multimeter that did the same thing.

The AM60 should serve your purposes.

[allsmith]

Re: Curtis lcd3215a Standby power only

One retiredcaps' bonus point for you.

I totally forgot I had an Amprobe AM-60. I got mine off ebay. When I had it, I liked most things about. I eventually sold it because I got a Fluke multimeter that did the same thing.

The AM60 should serve your purposes.

Nice thanks for the point !!