There is a random arcing between the pins of the crt neck connection on my CT-32HXC14J, worse on power up , gets less as it warms up. I have isolated it to under the plastic alignment cap that fits over the end of the CRT and its pins. After carefully cutting thru the sealant that holds the plastic cap to the CRT neck and cleaning off as much of the charred and blackened sealant as possible, the arcing has gone away. I need 2 things, 1 what should I check that might have caused it to start arcing, i.e. B+ too high, bias off, loose ground etc. and 2. whats the best way to clean off the glass around the pins to reduce the chance of re arcing? should I use some corona dope coating as well? Thanks
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It sounds that there is some arcing takes place inside it. High voltage arcing will produce and Ozone smell. Contact any TV technician. Never use this set at this condition. It might lead to more fault to internal circuit components.
tried to clean the anode cap and the crt tubes holes but make it sure before you do this, must have proper discharge of voltage from the tube.if still the same problem it could be the flyback transformer has problem.
I would check the remote control by taking it out of the room first. If that is not the problem, it is likely to be a dry joint in the power supply that is "arcing" and causing this problem. Re soldering the heavy components on the power supply board may fix it.
WATCH OUT FOR CHARGED UP CAPACITORS - THEY ARE LETHAL WHEN CHARGED!
Focus voltage on the CRT is usually in the range of 2-8 kV DC and should be controllable over a fairly wide range by the focus pot - usually located on the flyback or a little panel in its vicinity:
If adjusting the pot results in a position of acceptable focus, you may be done. It is not unusual for the focus setting to drift a over time.
If the setting is already as good as possible but not really good enough, the CRT may be tired. Alternatively, the filament voltage may be too low. Check for bad connections in the filament circuit.
If the optimal setting is out of range of the focus pot, the problem is likely leakage in the focus divider in the flyback or one of the components on the CRT neck board.
Also see the sections: "Focus adjustment" and "Focus drifts with warmup".
The focus wire usually comes from the flyback or if the general area or from a terminal on a voltage multiplier module in some cases. It is usually a wire by itself going to the little board on the neck of the CRT.
If a sparkgap (a little 2 terminal device with a 1/8" gap in the middle) is arcing with power on, then the resistive divider has shorted inside the flyback, focus board, or HV multiplier - whatever you TV has - and the this unit will need to be replaced. Ditto if the SCREEN control affects focus and/or vice-versa.
Using a suitable high voltage meter (range at least 10 kVDC, 1000 M ohm or greater input impedance), you should be able to measure it connected and disconnected. The ground return will be the outside coating of the CRT which may or may not be the same as the metal chassis parts. If the voltage is very low (less than 2 kV) or too high and the pot has little effect:
When measured right off of the source disconnected from the CRT neck board, then the problem is probably in the focus network in the flyback (or wherever it originates). Sometimes these can be disassembled and cleaned or repaired but usually requires replacement of the entire flyback or voltage multiplier. Note: you may need to add a HV (10 kV) capacitor between the focus wire and DAG ground to provide filtering so you get a DC level for your meter.
When measured with the focus wire attached to the CRT neck board with the CRT connected but reasonable with the CRT unplugged, there is probably a short between the focus and another electrode inside the CRT. See the section: Rescuing a shorted CRT.
When measured with the focus wire attached to the CRT neck board with the CRT unplugged, there is likely a component on the CRT neck board that is leaky or breaking down. Also, check for decayed (tan or brown) glue which may turn leaky with age. Good Luck...
arcing may be cause of prolonged dusts holds near the anode cap. so you have to clean the area by removing the cap. see also if the cap has been damaged by arcing. if damaged like cracks please change. when you remove the cap you must be aware of high voltage that is stored in the picture tube so you have to discharge it first.
The snap you hear is likely from the high voltage in the set. The worst case scenario is that the picture tube (CRT) is shorted and is arcing internally causing the set to shut down. There are other less expensive possibilities such as the flyback transformer which can also fail in such a way as to arc. You may be able to see through the top ventilation slots in back as you power the set. The neck of the tube extends back into the rear cabinet and you could possibly see a flash inside the tube neck if it is arcing. I would have to recommend you have a technician check this problem to diagnose it. The tube, if it is defective and out of warranty, would exceed the cost of replacing the TV. Check your warranty as the tube generally has a two year warranty and other parts one year with 90 days on labor.
The loud "pop" sounds like high voltage arcing coming from one of the CRT's.....you may have to pull each CRT out and put silicon sealant on the anode connectors to prevent the arcing.(one of the CRT's may be arcing internally also and the only cure is to replace that CRT) If you let the arcing continue,it will short out the horizontal output transistor sooner or later.......
Don't know what happened to the last post I sent you its disappeared.
What I think you should do is definately replace the CRT white socket (tube base plug).
You can either take the CRT number from the label on the tube & put it in to google then search for Crt base plug.
Or see if there is A repair shop local to you who can order the tube base for you.
Are you definately sure the arcing is external to tube & not happening in the tube neck ?
Is the CRT made by LG / PHILIPS. These are notorius for for arcing over internally I must write at least 1 A week off for this problem.
If you can still run the set try tapping the neck of tube with screwdriver handle if pic flashes or goes predominately1 colour you are looking at the tube with internal short.
If this is the case there are ways of trying to get rid of the internal short let me know what you find ?