Everyone knows about resisters in series/parallel but very few know how to make a Bi Polar capacitor. I always remember this as it was a question in one of my electrical papers at collage. I think I have only had to make one just once in my life, quite hard to find these days.
+Michael Beeny Learned that back in 1979, while still in high school and started my apprenticeship in electronic diagnoses. The guy I learned from had been an engineer in the Canadian forces.
bi polar electrolytic caps are still around, and new, think it was nichicon I was finding for a guy last week, I work in component distribution, too many franchises where I work to remember them all.
same circuit is used in the early macintosh systems, and I use a film cap to replace it. its not exact fit, but it works well and will for years to come.
This takes me back! I fixed hundreds of Wyse terminals which always had a failed bipolar cap on the H DY. The interesting thing with those Wyse terminals is typically after around 18 months they would always come back and need another new cap. I never did work out why the fault repeated so often, I did wonder if it was something related to the transformer.
+GadgetUK164 because using an electrolytic in a high voltage, high current pulsing circuit is not really a good idea. thats why towards the end of the CRT era, they did away with it and used film caps. the high pulses means high ripple current which dries out caps.
Great video as always sir. Thanks for prior information about this upload. I enjoyed a lot your great repair. You remembered me one of my television repair long ago vertical deflection problem with same one capacitor defect. That time I fixes that one without using a scope but test with scope and repairing have great value. Your upload effort is of countless reward! Keep up more and more great videos. Always looking forward for your uploads. Regards,
Even before tracing to the inductor, you see the other direction going to a capacitor with crusty solder points, possibly due to leakage from the other side.
Can't believe I stumbled upon this video lol that tv is really rare (at least the SONY version of it is). Got my hands on one a few weeks ago that was abandoned since 1996 in a old repair shop. Seems like it was dropped while it was a security screen for some sort of armory. I got it to power on after some hours but the screen is REALLY dim.
@@12voltvids Oh thats nice. Do you have any suggestions on what could be causing it to be very dim? I already found & fixed a bad solder joint that was causing a no power situation. Going to take another look at it next weekend. Maybe your advice could point me in the right direction.
@@Shyzah Look at the video driving the picture tube. If you have good strong video driving the tube, and there is no or little output then the CRT is weak.
Once i was soldering dry joins around HV trafo while with the left hand holding tv chassis from the tuner.A capacitor 10uf/250v remained charged and when touched with the soldering iron tip i felt a shock to both hands.After that the microprocessor gone dead forever.The plastic holder of the soldering iron is antistatic so it is conductive and i already knew that from previous times,but i should not have touched the small signal area with the other hand.
+Amy Marie Lcd there is so little you can do. I like plasma as they are a challenge, but of course analog crt TV. Al those nice active and passive analog circuits to give troubles.
yeah nothing But Troubles. With CRT's at-least its kind of a one component "or two" failure, (the one that i worked on and am still restoring, needed to have all the caps shotgunned and replaced.. and replace diodes on the jungle and gave the board an Isoprop Bath..) It was something that i really wanted to have, my own proper Color CRT TV.
+Amy Marie I have a few to restore. A couple of 80's Sony trinitron, a few mitsubishi, Sets and 2 tektronix studio rack monitors. Those ones will be featured in an upcoming video.
+Amy Marie Something I wish I still had was the old Philips K6 chassis that my grandmother had. I watched the moon landing on that set. I had it in my garage when a workman working on my house dropped a stack of 2x6 on it and broke the CRT. I was not happy. That was an all tube color set, and I would have loved to restore it.
Ive found that the plugs on the deflection wires burn up, i think its dampness that makes them a bad joint. (its mad but its true). Ive often just snipped off the plugs and soldered the wires direct into the pcb, never ever fails again :-) Nothing better than bringing an old crt unit back to life and adjusting all the presets for best geometry of picture and focus :-D
+zx8401ztv Yup, there is just something cool about that old tech that is missing in todays boring digital age. One of the things I like about plasma is the high voltage, lighting up those individual pixels with an electric arc.Just like an old mercury lamp, or metal halide lamp. Producing light from nothing more than blasting electrons through a gas and some mercury. Neon too. Nothing more than high voltage and some neon gas and you get light.
+12voltvids Magic producing a picture :-D I dont like lcd displays, i have a small laptop computer and that does fine for schematic diagrams and youtube videos, but i gave up tv sets a while back. Our stupid govenment has forced a crap digital tv system that delivers worse quality than the earlier better analog system. No point in tv now, and im not paying the bbc for a licence to watch a comically named "Freeview box", its not free or good. Sorry i yap a lot :-(
+James Lane Non polarized capacitors come in 2 types, mylar and electrolytic. An electrolytic nonpolarized capacitor is actually two capacitors in series (back to back) in one case, hence the large physical size for the voltage and capacity. Polarized capacitors have very large leakage current if the voltage is inverted. Nonpolarized capacitors are needed at AC applications in series or in parallel with the signal (or power). Examples are speaker crossover filters and power factor correction networks. In both applications a large voltage AC signal is applied accross the capacitors. If polarized types were used the leakage current would distort the signal and overheat the capacitor and potentially destroy it. In the TV deflection circuit the capacitor couples the AC signal to ground while blocking the DC component. Due to the high reversal current kick at retrace (flyback) this current reversal would destroy a polarized capacitor in a short time. For example the capacitor in an electric motor is an AC or non-polarized capacitor for this reason.
I wish that all PCBs were like this. Would a tweeter crossover cap work in this circuit? Isn't it better to have the scope connected to the mains, but the device on the isolation transformer? I don't connect the scope on the I.T., it's direct on my bench power strip. What about using a GFCI socket on the power strip? I've thought about adding a ground fault socket for the power strip. Don
+umajunkcollector The scope is not isolated. It need to be grounded for safety. Only the device is isolated. That is to protect the Tech from a shock shook they touch a hot circuit and earth at the sam time. You can still get a shock if you make contact between 2 points of a circuit such as between the + / - terminal of a power supply, which can bite, but is usually not that hazardous. The real danger is on non isolated chassis making contact with an energized line operate chassis and an external ground such as a cable TV coax. Then you become the conductor for mains, or your scope lead does. By having the chassis floating you remove that Hazzard.
ten-four, heh heh, um working on an isolation power supply project. I will actually fuse the ground pin of the secondary, only to protect against incidental short circuits as mentioned in your vid, most likely a 5 amp fuse. I normally would NOT fuse the neutral side, but when their is the possibility of a short circuit at higher voltage, why not! I don't know if a 5 amp fuse will save a probe, but a full short certainly will. I want no connection of the secondary shared with ground, but there will be a three prong outlet off of the secondary with a fused ground pin, so there is a connection with the primary ground there that could bridge to the secondary in a chassis. I normally use polarized two prong plugs on the secondary anyhow. But if something hapens to have a three prong plug, I can either use one of those 3 to 2 prong adapters, or at least there is a fuse just in case. The fuse will only be on the ground pin of the secondary outlet. GFCI would be protection against electrocution. But it may fail on the secondary, so that may be moot. Don
+umajunkcollector I think you fail to understand how an isolation transformer works. The entire point is to isolate you from ground when you are working on a piece of equipment. You want the entire chassis isolated from ground period. No ground prong at all. This way the secondary becomes a balanced output. Either side of the secondary could short to ground or go through your body and you are isolated from mains voltage. That is the way you are protected. Hot chassis typically have the neutral directly connected to the chassis which creates a dangerous situation if a non polarized plug is used or if the outlet is wired backwards. You would be amazed how often that happens. Also depending on the size of your transformer this will limit the amount of current that can be drawn. If you have a 500 watt transformer that is all you will get without overheating it and tripping the thermal circuit breaker that all commercial isolation transformers have. They are self resetting as soon as it cools down.
Yah, I know. I have an older two prong outlet, that totally eliminates the possibility of using a three prong plug. Mine will be home brew, using a nice surplus transformer that I got. I hope to complete the vid on it next week. I've used polarized and three prong plugs in restorations many times to prevent the reverse hot chassis problem. The trick is to not connect the gound pin, just in case the wall outlet is reversed. But in my house there are NO improper wall outlets! Some older homes with knob and tube have reversed outlets though, and some bozos put three prong sockets in the wall, not knowing which side is hot. Don
+umajunkcollector Ues a crossover capacitor would work fine if the voltage rating was high enough. The capacitor is just to block the DC component otherwise you would short your B+ to ground.
Great video , I've done the same thing making a non polarized capacitor . I'm a novice at this and have a question if you don't mind . I have a 2 channel analog oscilloscope vertical position problem . My trace will not come down to center on the screen . With the vertical control knob turned fully counter clockwise it is still above the center . Turner fully clockwise , it's off the top of the screen . Both channels . I think it would be in the vertical deflection circuit . I'm I correct and what component might you check first ? You seem very knowledgeable . I'm definitely going to check out your other videos and subscribe . Thanks again
Could be one of the drive IC to the tube. They use static deflection, and a balanced amplifier, one outout driving one deflection plate and the other one driving the other plate. I have a vectorscope with a bad drive IC that does the same thing, and has a bad drive IC. I forget the jumper of it off hand, but it is round and looks like a transistor but has about 8 leads sticking out the base of it like a tube. That is if it is a solid state scope. If a vacuum tube scope then a good chance one of the tubes has gone bad.
is it possible to find industrial crt b/w security analog monitor. And if you know maybe mark and type or product name. I am very interested for this type of analog display. Tnx!
hello.How can I make non-polarized caps(50v 5.6uf) from polarized cap? And Is it OKAY to use any polarized cap in order to make non-polarized caps for Horizontal Deflection Current Correction in TV or monitor?
Yes you can make a non polarized cap from 2 polarized wired in aeeies. You connect the 2 negative terminals together and the + from each goes to the circuit. You have to double the size. So 2 10uF would give you a 5uF NP cap.
@@12voltvids Thank you very much for reply! the non-polarized caps(50v, 5.6uf, size of 16×35.5mm ),which I want to replace with, is samwha NF series which was desoldered from LG 29 inch CRT TV. So I browsed through samwha catalouge,and It say that designed for "Horizontal Deflection Current Correction in TV or monitor", "Stable characteristic at high frequency and high ripple current","Complied to the RoHS directive".Is It really no matter to use any polarized cap which has low grade specification or low ripple current? Is it okay to use two 10uF 50V 85℃ Samyoung SHL capacitor series(size of 5×11mm) in order to make non-polarized caps for Horizontal Deflection Current Correction?
hey I noticed in a couple of videos some of your equipment has bnc jacks as audio or video input and outputs all that equipment is not consumer level stuff. Is it only industrial equipment that did that? b4 anyone says anythings i dont mean radios i know they do but that awesome monitor uses bnc and he did one on a 8mm or betamax tape player that was made of production work like editing where the board with the outputs and inputs was all broken into pieces.
In the UK, consumer TVS, Vhs recorders and some hifi's made in the 70s, 80s had bnc inputs and outputs for audios and videos but those inputs were phased out by the late 80s in favour of rca jacks and scart sockets.
Isolates the yoke from the B+ rail while passing the AC pulse and provides the ramp for the sweep. If you look at the pulse of there was no capacitor the spot would fly off the screen and then snap back to center till the next pulse. The cap charges quick and then decays and as the voltage decays the beam is drawn across the screen.
hi mister i need your help please i have a probleme with a samsung crt tv model cs-761bgv the tv turn on and shut down i look for the probleme i saw that the power swicth is faulty i replace it the tv stay on the image come i thing its ok but suddenly the image gone the screen stay black please help me many thanks daniel rock everyday i wacth your video on youtub
What a wonderful video!! I understood literally everything you mentioned & did. You're a great teacher.
Everyone knows about resisters in series/parallel but very few know how to make a Bi Polar capacitor. I always remember this as it was a question in one of my electrical papers at collage. I think I have only had to make one just once in my life, quite hard to find these days.
+Michael Beeny Learned that back in 1979, while still in high school and started my apprenticeship in electronic diagnoses. The guy I learned from had been an engineer in the Canadian forces.
bi polar electrolytic caps are still around, and new, think it was nichicon I was finding for a guy last week, I work in component distribution, too many franchises where I work to remember them all.
same circuit is used in the early macintosh systems, and I use a film cap to replace it. its not exact fit, but it works well and will for years to come.
This takes me back! I fixed hundreds of Wyse terminals which always had a failed bipolar cap on the H DY. The interesting thing with those Wyse terminals is typically after around 18 months they would always come back and need another new cap. I never did work out why the fault repeated so often, I did wonder if it was something related to the transformer.
+GadgetUK164 I was going to make a joke about the Bi-Polar capacitor being off its meds, but I didn't want to draw fire from anyone.
LMAO!
+GadgetUK164 because using an electrolytic in a high voltage, high current pulsing circuit is not really a good idea. thats why towards the end of the CRT era, they did away with it and used film caps. the high pulses means high ripple current which dries out caps.
Great video as always sir. Thanks for prior information about this upload. I enjoyed a lot your great repair. You remembered me one of my television repair long ago vertical deflection problem with same one capacitor defect. That time I fixes that one without using a scope but test with scope and repairing have great value. Your upload effort is of countless reward! Keep up more and more great videos. Always looking forward for your uploads. Regards,
Thanks for your videos. Please don't get tired.
Even before tracing to the inductor, you see the other direction going to a capacitor with crusty solder points, possibly due to leakage from the other side.
You are a wealth of knowledge!
Can't believe I stumbled upon this video lol that tv is really rare (at least the SONY version of it is). Got my hands on one a few weeks ago that was abandoned since 1996 in a old repair shop. Seems like it was dropped while it was a security screen for some sort of armory. I got it to power on after some hours but the screen is REALLY dim.
I have another one, a JVC which is like new. Use it to display the time.
@@12voltvids Oh thats nice. Do you have any suggestions on what could be causing it to be very dim? I already found & fixed a bad solder joint that was causing a no power situation. Going to take another look at it next weekend. Maybe your advice could point me in the right direction.
@@Shyzah Look at the video driving the picture tube. If you have good strong video driving the tube, and there is no or little output then the CRT is weak.
What did you chose as replacement capacitor ? One that supports high frequencies I guess 15 Khz or have I misunderstood something ?
Another safety tip is to work on it with one hand whenever possible so that a shock doesn't cross your heart.
One hand in your pocket when possible.
Once i was soldering dry joins around HV trafo while with the left hand holding tv chassis from the tuner.A capacitor 10uf/250v remained charged and when touched with the soldering iron tip i felt a shock to both hands.After that the microprocessor gone dead forever.The plastic holder of the soldering iron is antistatic so it is conductive and i already knew that from previous times,but i should not have touched the small signal area with the other hand.
Sweet! I do TV repairs Too! i prefer CRT's over LCD's i have every component you might need. to repair a CRT
+Amy Marie
Lcd there is so little you can do. I like plasma as they are a challenge, but of course analog crt TV. Al those nice active and passive analog circuits to give troubles.
yeah nothing But Troubles. With CRT's at-least its kind of a one component "or two" failure, (the one that i worked on and am still restoring, needed to have all the caps shotgunned and replaced.. and replace diodes on the jungle and gave the board an Isoprop Bath..) It was something that i really wanted to have, my own proper Color CRT TV.
+Amy Marie
I have a few to restore. A couple of 80's Sony trinitron, a few mitsubishi,
Sets and 2 tektronix studio rack monitors. Those ones will be featured in an upcoming video.
can't wait to see them :D
+Amy Marie Something I wish I still had was the old Philips K6 chassis that my grandmother had. I watched the moon landing on that set. I had it in my garage when a workman working on my house dropped a stack of 2x6 on it and broke the CRT. I was not happy. That was an all tube color set, and I would have loved to restore it.
Ive found that the plugs on the deflection wires burn up, i think its dampness that makes them a bad joint. (its mad but its true).
Ive often just snipped off the plugs and soldered the wires direct into the pcb, never ever fails again :-)
Nothing better than bringing an old crt unit back to life and adjusting all the presets for best geometry of picture and focus :-D
+zx8401ztv Yup, there is just something cool about that old tech that is missing in todays boring digital age. One of the things I like about plasma is the high voltage, lighting up those individual pixels with an electric arc.Just like an old mercury lamp, or metal halide lamp. Producing light from nothing more than blasting electrons through a gas and some mercury. Neon too. Nothing more than high voltage and some neon gas and you get light.
+12voltvids Magic producing a picture :-D
I dont like lcd displays, i have a small laptop computer and that does fine for schematic diagrams and youtube videos, but i gave up tv sets a while back.
Our stupid govenment has forced a crap digital tv system that delivers worse quality than the earlier better analog system.
No point in tv now, and im not paying the bbc for a licence to watch a comically named "Freeview box", its not free or good.
Sorry i yap a lot :-(
Great video. Why was that non polorized? Also why are they in crossover networks and not electrolitics? Jimmy in Alabama
+James Lane Non polarized capacitors come in 2 types, mylar and electrolytic. An electrolytic nonpolarized capacitor is actually two capacitors in series (back to back) in one case, hence the large physical size for the voltage and capacity.
Polarized capacitors have very large leakage current if the voltage is inverted. Nonpolarized capacitors are needed at AC applications in series or in parallel with the signal (or power). Examples are speaker crossover filters and power factor correction networks. In both applications a large voltage AC signal is applied accross the capacitors. If polarized types were used the leakage current would distort the signal and overheat the capacitor and potentially destroy it. In the TV deflection circuit the capacitor couples the AC signal to ground while blocking the DC component. Due to the high reversal current kick at retrace (flyback) this current reversal would destroy a polarized capacitor in a short time. For example the capacitor in an electric motor is an AC or non-polarized capacitor for this reason.
I wish that all PCBs were like this.
Would a tweeter crossover cap work in this circuit?
Isn't it better to have the scope connected to the mains, but the device on the isolation transformer? I don't connect the scope on the I.T., it's direct on my bench power strip. What about using a GFCI socket on the power strip? I've thought about adding a ground fault socket for the power strip. Don
+umajunkcollector
The scope is not isolated. It need to be grounded for safety. Only the device is isolated. That is to protect the Tech from a shock shook they touch a hot circuit and earth at the sam time. You can still get a shock if you make contact between 2 points of a circuit such as between the + / - terminal of a power supply, which can bite, but is usually not that hazardous. The real danger is on non isolated chassis making contact with an energized line operate chassis and an external ground such as a cable TV coax. Then you become the conductor for mains, or your scope lead does. By having the chassis floating you remove that Hazzard.
ten-four, heh heh, um working on an isolation power supply project. I will actually fuse the ground pin of the secondary, only to protect against incidental short circuits as mentioned in your vid, most likely a 5 amp fuse. I normally would NOT fuse the neutral side, but when their is the possibility of a short circuit at higher voltage, why not! I don't know if a 5 amp fuse will save a probe, but a full short certainly will. I want no connection of the secondary shared with ground, but there will be a three prong outlet off of the secondary with a fused ground pin, so there is a connection with the primary ground there that could bridge to the secondary in a chassis. I normally use polarized two prong plugs on the secondary anyhow. But if something hapens to have a three prong plug, I can either use one of those 3 to 2 prong adapters, or at least there is a fuse just in case. The fuse will only be on the ground pin of the secondary outlet. GFCI would be protection against electrocution. But it may fail on the secondary, so that may be moot. Don
+umajunkcollector
I think you fail to understand how an isolation transformer works. The entire point is to isolate you from ground when you are working on a piece of equipment. You want the entire chassis isolated from ground period. No ground prong at all. This way the secondary becomes a balanced output. Either side of the secondary could short to ground or go through your body and you are isolated from mains voltage. That is the way you are protected. Hot chassis typically have the neutral directly connected to the chassis which creates a dangerous situation if a non polarized plug is used or if the outlet is wired backwards. You would be amazed how often that happens. Also depending on the size of your transformer this will limit the amount of current that can be drawn. If you have a 500 watt transformer that is all you will get without overheating it and tripping the thermal circuit breaker that all commercial isolation transformers have. They are self resetting as soon as it cools down.
Yah, I know. I have an older two prong outlet, that totally eliminates the possibility of using a three prong plug. Mine will be home brew, using a nice surplus transformer that I got. I hope to complete the vid on it next week. I've used polarized and three prong plugs in restorations many times to prevent the reverse hot chassis problem. The trick is to not connect the gound pin, just in case the wall outlet is reversed. But in my house there are NO improper wall outlets! Some older homes with knob and tube have reversed outlets though, and some bozos put three prong sockets in the wall, not knowing which side is hot. Don
+umajunkcollector Ues a crossover capacitor would work fine if the voltage rating was high enough. The capacitor is just to block the DC component otherwise you would short your B+ to ground.
Great video , I've done the same thing making a non polarized capacitor . I'm a novice at this and have a question if you don't mind . I have a 2 channel analog oscilloscope vertical position problem . My trace will not come down to center on the screen . With the vertical control knob turned fully counter clockwise it is still above the center . Turner fully clockwise , it's off the top of the screen . Both channels . I think it would be in the vertical deflection circuit . I'm I correct and what component might you check first ? You seem very knowledgeable . I'm definitely going to check out your other videos and subscribe . Thanks again
I meant AM I correct ! Sorry
Could be one of the drive IC to the tube. They use static deflection, and a balanced amplifier, one outout driving one deflection plate and the other one driving the other plate. I have a vectorscope with a bad drive IC that does the same thing, and has a bad drive IC. I forget the jumper of it off hand, but it is round and looks like a transistor but has about 8 leads sticking out the base of it like a tube.
That is if it is a solid state scope. If a vacuum tube scope then a good chance one of the tubes has gone bad.
12voltvids Thank you very much . It is solid state . That's one of the first things I'll look at .
is it possible to find industrial crt b/w security analog monitor. And if you know maybe mark and type or product name. I am very interested for this type of analog display. Tnx!
Thank you for sharing with us your videos. i wish to become your student.
Shane Murphy
You can always subscribe through patreon to see private videos.
Sounds great Sir. Now iknow.
hello.How can I make non-polarized caps(50v 5.6uf) from polarized cap? And Is it OKAY to use any polarized cap in order to make non-polarized caps for Horizontal Deflection Current Correction in TV or monitor?
Yes you can make a non polarized cap from 2 polarized wired in aeeies. You connect the 2 negative terminals together and the + from each goes to the circuit. You have to double the size. So 2 10uF would give you a 5uF NP cap.
@@12voltvids Thank you very much for reply! the non-polarized caps(50v, 5.6uf, size of 16×35.5mm ),which I want to replace with, is samwha NF series which was desoldered from LG 29 inch CRT TV. So I browsed through samwha catalouge,and It say that designed for "Horizontal Deflection Current Correction in TV or monitor", "Stable characteristic at high frequency and high ripple current","Complied to the RoHS directive".Is It really no matter to use any polarized cap which has low grade specification or low ripple current? Is it okay to use two 10uF 50V 85℃ Samyoung SHL capacitor series(size of 5×11mm) in order to make non-polarized caps for Horizontal Deflection Current Correction?
love your work dude
hey I noticed in a couple of videos some of your equipment has bnc jacks as audio or video input and outputs all that equipment is not consumer level stuff. Is it only industrial equipment that did that? b4 anyone says anythings i dont mean radios i know they do but that awesome monitor uses bnc and he did one on a 8mm or betamax tape player that was made of production work like editing where the board with the outputs and inputs was all broken into pieces.
In the UK, consumer TVS, Vhs recorders and some hifi's made in the 70s, 80s had bnc inputs and outputs for audios and videos but those inputs were phased out by the late 80s in favour of rca jacks and scart sockets.
eddy apple Literally all of my vintage VCRs use BNC. I don't know why the NTSC machines didn't use them.
What does the bipolar capacitor do in the crt circuit?
Isolates the yoke from the B+ rail while passing the AC pulse and provides the ramp for the sweep. If you look at the pulse of there was no capacitor the spot would fly off the screen and then snap back to center till the next pulse. The cap charges quick and then decays and as the voltage decays the beam is drawn across the screen.
Great video, Thank you
Great Fix...
good stuff, thank you...
hi mister i need your help please i have a probleme with a samsung crt tv model cs-761bgv the tv turn on and shut down i look for the probleme i saw that the power swicth is faulty i replace it the tv stay on the image come i thing its ok but suddenly the image gone the screen stay black please help me many thanks daniel rock everyday i wacth your video on youtub
perfeito!
Thanks for shareing
Nice too
what does it take to be you. because thats what i wanna be.
You want to me a millionaire?
@@12voltvids I want to be a cool ass dude who knows about CRTs
Do you have a Facebook account?
Nope
5*****
Pong!!