CRT television that won't turn on
DoctorWho93
-
DoctorWho93 -
DoctorWho93 -
Hello,
I have a CRT television that was working perfectly until the day I disassembled it to repair the built-in VCR. But now I have another problem: I can't turn on the screen. When I try to turn it on, there is a tiny buzzing sound, and a second later, the buzzing stops and the red LED blinks. From what I understand, the television may have gone into "protection" mode because there is a fault somewhere, which I probably caused during disassembly when I fiddled a bit with the circuit board. It might be related to a transistor, because after leaving the TV plugged in for 1 or 2 minutes, that transistor got very hot, but not the others. If you know about CRT televisions or think you have a solution to my problem, please help me.
Configuration: Android / Chrome 74.0.3729.136
I have a CRT television that was working perfectly until the day I disassembled it to repair the built-in VCR. But now I have another problem: I can't turn on the screen. When I try to turn it on, there is a tiny buzzing sound, and a second later, the buzzing stops and the red LED blinks. From what I understand, the television may have gone into "protection" mode because there is a fault somewhere, which I probably caused during disassembly when I fiddled a bit with the circuit board. It might be related to a transistor, because after leaving the TV plugged in for 1 or 2 minutes, that transistor got very hot, but not the others. If you know about CRT televisions or think you have a solution to my problem, please help me.
Configuration: Android / Chrome 74.0.3729.136
3 answers
-
Hi, it's probably a power supply failure at the lowest level, that is to say at the mains input; it's likely that the return from the power supply for management is defective. Without specific knowledge or any dedicated troubleshooting tools, it's not a good idea to perform any manipulation on this kind of circuit directly connected to the mains.
-
Hello,
For safety reasons, it is generally more than imperative to discharge the capacitors afterwards, that's the basic principle.
--
The enemy is stupid: he thinks we are the enemy when it is actually him!
Pierre Desproges -
" Always unplug devices when handling them or changing a soldered or plugged component, remember to discharge capacitors .. "
https://www.eyrolles.com/Chapitres/9782212676211/9782212676211.pdf
--
The enemy is stupid: he believes that we are the enemy when it is actually him!
Pierre Desproges-
I have read your responses and I want to reassure you: I have knowledge in electricity and I discharged the capacitors and the parts that remain charged every time I plugged in the television, so don't think I'm doing anything careless. To get back to the problem of the failure, I agree with Narssad, the issue definitely comes from the power supply because that's where we can hear a component whistling (probably the transistor, the one that heats up a lot). So, should I change the transistor, replace something else? Tell me how to fix this television. Thank you.
-
Good evening,
It's probably a faulty power transistor (they are mostly 2n3055 type transistors). I don't think it's a power supply issue because the light is on. Turn the unit on and check the filament in the tube socket to see if it is very dim or off. Be careful with the high voltage part.
-
