When I left high school, I went to work in a small local TV repair shop, quite a few actually over the years. I still love doing projects to this day. I really enjoy your videos, I'm not that far away either! I'm from ocean park BC! Best wishes!
I only worked in 2 shops, and for Sony Canada for a year. I did an aprentiship at one, worked for Sony for a year, and then went to another larger shop where I put in 20 years. Got out while I still had my sanity.
Good demonstration of the shunt transistor going bad :-D. The old philips G8 tv's had a rather dodgy psu, it would creap up slowly as it got older. The overvoltage circuit was supposed to jump in, but it often failed and the psu would blow its brains out lol.
I have a problem with my 1986 CRT computer monitor (Grundig BGC36, pretty rare, no schematics). It just stays black and won't display any picture but the green power LED comes on. When ever I try to turn it on after it sat for a while, it sounds (for a split second) like it comes on but then nothing happens. Do you have any ideas?
Hi, I have a Sony KV-27FS100 which is working fine but when I turn off the tv a big green dot appears on the screen and vanish in around 5 seconds, I suspect of a devalorated electrolitic capacitor I don't know where.....what do you think it could be this emerging problem ? Thanks in advance.
I have a Sony PVM/Profeel Pro set that turns off pretty much right after you turn it on. Sometimes in the past it would stay on for a while and maybe shut down, or you'd have to keep trying to turn it on over and over and eventually it would stay on. You think it has something to do with a regulator similar to this fault or something completely different?
The higher the input voltage the less the transistor conducts as the shunt resistor will dissipate most of it. When the voltage drops the transistor conducts more to allow more current to bypass the shunt resistor. So lower input voltage actually creates more heat in the junction.
My Crown amplifier needs a fan replacement and I can't find a original fan to replace it and it's hard to even find a fan dc 24v .15A brushless 80mm side to side and it's 25mm thick should I get a .14A or .17A or something higher Amp rating of fan? it's a 2 prong connection. Any help?
Hi I have a CRT that is heaving a similar problem. When plugged in ac mains TV stuck with stand by light. Also you can hear a tick noise and then high voltage shut down please can you explain what to look out for. Thank you .
@@BoogWar01 hi sorry my friend. Unfortunately I haven't still managed to fix the problem I am facing. So I give up on the dawn thing. 😃😍🥰. Many thanks.
We are at the end of a line, and a couple times, our voltage was too high. It also made my UPS beep and not work. Only after the lineman fixed the overvoltage, everything worked properly. Also, the overvoltage was on both legs of the power supply. (Hot wires) and the man that came out noticed that at the output of our pole transformer.
Our power company has given us about 132 volts, I wouldn't have known, except a tv kept shutting off, and our clothes dryer would too.I thought they both were defective, until I used my voltmeter. I called the power company and they fixed it. I live in a rural area, though.It has happened 2 times in 30 years.
It is quite common for utilities to turn the voltage up a bit in the rural areas to compensate for loss in long power lines. They want to make sure that customers at the end of the line receive enough power, as generally low voltage causes more damage to things that have big motors in them like refrigerators and air conditioners. They need big power to start up, and if they don't get enough, they can stall on start up and burn out. If you happen to be close to the substation then your voltage will be a little higher. 132 shouldn't cause any problems with modern electronics. The regulator in your device should be able to handle this slight over voltage no problem. I can crank my variac up to 150 volts, and no TV I have plugged in will shut down if the regulator in the TV is working correctly. You can call the power company, and let them know, and they will likely send someone to check the voltage especially if you are blowing light bulbs, equipment is damaged by it. Sometimes the neutral connection breaks down at the pole, and if that happens, then you end up with low voltage on the phase that is drawing the most in your house and high voltage on the side that is drawing the least. Another thing that can cause the voltage to appear high is if your electical panel load is not balanced correctly. Remember that in north america, we have split phase 120. 240 phase to phase. In your electrical panel, the breakers are arranged in typically 2 rows. AB AB AB AB AB AB soen one side and BA BA BA BA BA BA down the other side. Appliance that use 240V have a double breaker so they use both the A and B phase. If you have a bunch of high power loads plugged into plugs all on the "A" phase, and they are turned on, if you were to measure the voltage between A and neutral, the voltage might only real 108 or 110 volts, and if you go measure the voltage on a plug on the B phase that is under light load, the voltage would read high, 130 or 132. This is caused a phase imbalance and if this is constantly happening, consult a qualified electrician to have you panel load balanced. This is done by switching the order of some of the high load breakers (say air conditioners, or sump pumps ect) to the other phase to balance out the load and eliminate this voltage difference. Incidentally, before I got into electronics I had intended to become an electrician. I had a summer job working as an apprentice, but having to install ceiling fans in a hot attic while the licensed electrician was having a cold beer with the home owner while I sweated my ass off put me off that trade, but I learned enough in the summer that I did it to make me dangerous. Whoops, I meant, learned enough to know how to wire a house, and electrical panel. I did all my own wiring in my house, and pissed off the electrician I hired. I let him do all the grunt work, pulling wires ect, and then when he went home I wired all the plugs, switches, and appliances. When he returned to hook everything up, he was pissed as I had already called for inspection and it passed with flying colors. He was pissed because it was on "his" license. My response.... "Your fired"
It was on both legs of the circuit. The Electric company guy measured it at the transformer. I think it was actually 136 volts on both hot wires. We are at the end of a line. Our next door neighbor is on another company.
If they replaced the transformer that was likely a case of a shorted secondary (I've heard of this going into the 140s). It is also possible they had a voltage regulation problem on the primary side. Last time we had a primary problem we got lucky and didn't get the brunt of the surge (I guess we were at a place on the line that was de-tuned to the surge). A few years back the power company dropped a phase of a 34.5 kV line into a 12.45 kV line. The only thing I noticed when it happened was I heard what I thought was a shotgun (it was line fuses). We did loose one thing in that incident and I can't say for sure it was a result of the incident and that was a CFL went out shortly afterwards.
The service switch kills the vertical deflection so you have a straight line across the center. The correct way to use it is to feed in black video. (camera with Lens cap on works for this) turn service switch to on. Now adjust the red green and blue bias controls so that a faint white line is showing. This is to set the low level bias for the crt. Then turn service switch off and display a full white screen and adjust the red and blue drive controls to balance the pictire color balance for a bright screen. Bias adjusts the low level screen at cut off and drive the high level drive. The reason the single line is color black would not show anything with a full rastar. With vertical collapsed it makes the low emission for bias visable.
@@azariayehezkel9064 Some TV's it kills the video in service mode others just collapses the vertical. If it kills the video it is possible the switch contacts are dirty and when flipped back is not passing video but no it won't hurt the tv. Try flipping it back and forth.
Hey volt, glad i found your video. Can i ask some help from you hope you are still active in this email. I have a panasonic CRT TV with STK73907-T switching regulator IC, it wont power up and only click(relay) when pressing power ON but no display no raster, not even a magnetic field to touch my skin when i place my arm in front of the monitor when powering ON. I tried plugging it in a 110V outlet, it powers up normally but the display is orange yellow etc.weird. Our outlet is 220V here in our place, this appears to be overvoltage problem, can you give me idea where to look for the cause of the hight voltage? I measured the voltage from the output of the bridge diode in the primary and it appears to reach 350v to 390v. Thank you
Always a pleasure to see your videos filled with knowledge and experience!
When I left high school, I went to work in a small local TV repair shop, quite a few actually over the years. I still love doing projects to this day. I really enjoy your videos, I'm not that far away either! I'm from ocean park BC! Best wishes!
I only worked in 2 shops, and for Sony Canada for a year. I did an aprentiship at one, worked for Sony for a year, and then went to another larger shop where I put in 20 years. Got out while I still had my sanity.
I could learn a lot from you. I live locally too. Love to talk sometime about projects and such.
I would love to meet you "12volt" but I am in the UK 😞 lol. Paul
Good demonstration of the shunt transistor going bad :-D.
The old philips G8 tv's had a rather dodgy psu, it would creap up slowly as it got older.
The overvoltage circuit was supposed to jump in, but it often failed and the psu would blow its brains out lol.
I have a problem with my 1986 CRT computer monitor (Grundig BGC36, pretty rare, no schematics). It just stays black and won't display any picture but the green power LED comes on. When ever I try to turn it on after it sat for a while, it sounds (for a split second) like it comes on but then nothing happens. Do you have any ideas?
Hi, I have a Sony KV-27FS100 which is working fine but when I turn off the tv a big green dot appears on the screen and vanish in around 5 seconds, I suspect of a devalorated electrolitic capacitor I don't know where.....what do you think it could be this emerging problem ?
Thanks in advance.
This repair man is awesome
I have a Sony PVM/Profeel Pro set that turns off pretty much right after you turn it on. Sometimes in the past it would stay on for a while and maybe shut down, or you'd have to keep trying to turn it on over and over and eventually it would stay on. You think it has something to do with a regulator similar to this fault or something completely different?
narunetto DEATH.
Hi sir how can you help me with my sony pvm 1351q, the problem is shutingdown pretty much right after i turn it on.
does the regulator get hot enough to fail with the 130v overload. just curious how much abuse it will take to fail?
The higher the input voltage the less the transistor conducts as the shunt resistor will dissipate most of it. When the voltage drops the transistor conducts more to allow more current to bypass the shunt resistor. So lower input voltage actually creates more heat in the junction.
So if we have that problem what should do?
Hi sir how can you help me with my LG crt TV, the problem is shutingdown when cold.
My Crown amplifier needs a fan replacement and I can't find a original fan to replace it and it's hard to even find a fan dc 24v .15A brushless 80mm side to side and it's 25mm thick should I get a .14A or .17A or something higher Amp rating of fan? it's a 2 prong connection. Any help?
Hi I have a CRT that is heaving a similar problem. When plugged in ac mains TV stuck with stand by light. Also you can hear a tick noise and then high voltage shut down please can you explain what to look out for. Thank you
.
Have the same problem. Did you fix yours?
@@BoogWar01 hi sorry my friend. Unfortunately I haven't still managed to fix the problem I am facing. So I give up on the dawn thing. 😃😍🥰. Many thanks.
its like school, good teaching. thanks.
hi..my sharp 21inch CRT tv dies after I turn it on how can I fix this,I did change all the capacitor and its still the same..
We are at the end of a line, and a couple times, our voltage was too high. It also made my UPS beep and not work. Only after the lineman fixed the overvoltage, everything worked properly. Also, the overvoltage was on both legs of the power supply. (Hot wires) and the man that came out noticed that at the output of our pole transformer.
your camera is amazing. High quality
Our power company has given us about 132 volts, I wouldn't have known, except a tv kept shutting off, and our clothes dryer would too.I thought they both were defective, until I used my voltmeter. I called the power company and they fixed it. I live in a rural area, though.It has happened 2 times in 30 years.
It is quite common for utilities to turn the voltage up a bit in the rural areas to compensate for loss in long power lines. They want to make sure that customers at the end of the line receive enough power, as generally low voltage causes more damage to things that have big motors in them like refrigerators and air conditioners. They need big power to start up, and if they don't get enough, they can stall on start up and burn out. If you happen to be close to the substation then your voltage will be a little higher. 132 shouldn't cause any problems with modern electronics. The regulator in your device should be able to handle this slight over voltage no problem. I can crank my variac up to 150 volts, and no TV I have plugged in will shut down if the regulator in the TV is working correctly. You can call the power company, and let them know, and they will likely send someone to check the voltage especially if you are blowing light bulbs, equipment is damaged by it.
Sometimes the neutral connection breaks down at the pole, and if that happens, then you end up with low voltage on the phase that is drawing the most in your house and high voltage on the side that is drawing the least.
Another thing that can cause the voltage to appear high is if your electical panel load is not balanced correctly.
Remember that in north america, we have split phase 120. 240 phase to phase. In your electrical panel, the breakers are arranged in typically 2 rows.
AB AB AB AB AB AB soen one side and BA BA BA BA BA BA down the other side.
Appliance that use 240V have a double breaker so they use both the A and B phase. If you have a bunch of high power loads plugged into plugs all on the "A" phase, and they are turned on, if you were to measure the voltage between A and neutral, the voltage might only real 108 or 110 volts, and if you go measure the voltage on a plug on the B phase that is under light load, the voltage would read high, 130 or 132. This is caused a phase imbalance and if this is constantly happening, consult a qualified electrician to have you panel load balanced. This is done by switching the order of some of the high load breakers (say air conditioners, or sump pumps ect) to the other phase to balance out the load and eliminate this voltage difference.
Incidentally, before I got into electronics I had intended to become an electrician. I had a summer job working as an apprentice, but having to install ceiling fans in a hot attic while the licensed electrician was having a cold beer with the home owner while I sweated my ass off put me off that trade, but I learned enough in the summer that I did it to make me dangerous. Whoops, I meant, learned enough to know how to wire a house, and electrical panel.
I did all my own wiring in my house, and pissed off the electrician I hired. I let him do all the grunt work, pulling wires ect, and then when he went home I wired all the plugs, switches, and appliances. When he returned to hook everything up, he was pissed as I had already called for inspection and it passed with flying colors. He was pissed because it was on "his" license.
My response.... "Your fired"
It was on both legs of the circuit.
The Electric company guy measured it at the transformer.
I think it was actually 136 volts on both hot wires. We are at the end of a line. Our next door neighbor is on another company.
If they replaced the transformer that was likely a case of a shorted secondary (I've heard of this going into the 140s). It is also possible they had a voltage regulation problem on the primary side. Last time we had a primary problem we got lucky and didn't get the brunt of the surge (I guess we were at a place on the line that was de-tuned to the surge). A few years back the power company dropped a phase of a 34.5 kV line into a 12.45 kV line. The only thing I noticed when it happened was I heard what I thought was a shotgun (it was line fuses).
We did loose one thing in that incident and I can't say for sure it was a result of the incident and that was a CFL went out shortly afterwards.
Could you do a video on how the over-voltage shutdown circuit works?
Sure after I fix my scope!
My Scope needs Fixing' too...Tektronix 465B...Traces way off to one side!?!?
Not for nothing but I have learned alot from 12volts.
Man I always hated the high pitch sound from those tube tv's i'm not sure if you could hear it but I certainly can
Sure could hear it.
Learned to tune it out after awhile.
I can't hear it like I used to. I am in my 50's.
Up to my 30's, I could tell if a tv was on, even if there was no sound or picture.
im used to it
can u make a video on how to voltage check the sections of crt tv?
In my tv have switch in the chasiss.
Left write service in right write normal.
When the switch in service have just horizontal line
What that switch?
The service switch kills the vertical deflection so you have a straight line across the center. The correct way to use it is to feed in black video. (camera with Lens cap on works for this) turn service switch to on. Now adjust the red green and blue bias controls so that a faint white line is showing. This is to set the low level bias for the crt. Then turn service switch off and display a full white screen and adjust the red and blue drive controls to balance the pictire color balance for a bright screen.
Bias adjusts the low level screen at cut off and drive the high level drive. The reason the single line is color black would not show anything with a full rastar. With vertical collapsed it makes the low emission for bias visable.
Thanks
For fast reply
It shouldn't ruin the tv?
Because after the switching my tv is dead.
Thr switching in power tv or need shout down?
@@azariayehezkel9064
Some TV's it kills the video in service mode others just collapses the vertical. If it kills the video it is possible the switch contacts are dirty and when flipped back is not passing video but no it won't hurt the tv.
Try flipping it back and forth.
Thanks
Good chanel i subscribed
@@12voltvids
Yes. I tested in another tv does have this switch.
In power on , work perfect.
Not need to power off. In that test.
Thanks for yours help
Hey volt, glad i found your video. Can i ask some help from you
hope you are still active in this email. I have a panasonic CRT TV
with STK73907-T switching regulator IC, it wont power up and only
click(relay) when pressing power ON but no display no raster,
not even a magnetic field to touch my skin when i place my arm in
front of the monitor when powering ON. I tried plugging it in a 110V
outlet, it powers up normally but the display is orange yellow etc.weird.
Our outlet is 220V here in our place, this appears to be overvoltage
problem, can you give me idea where to look for the cause of the
hight voltage? I measured the voltage from the output of the bridge
diode in the primary and it appears to reach 350v to 390v. Thank you
thank you
yummy ,,, cat is back
Nice job
You are preparing videos so that I can help people but I do not write you so much but I do not help you distinguish me condemn you
Wow I had one of those from like 1991
Thank you!
hi..my samsung tv capacitor 470uF 25v bloated and amoked
Bad transistor
D real master of electronics technician is joey tech ph go to his utube channel and subscribe then u learn a lot more about trouble shooting.