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/diy/ - Do It Yourself

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1363118

CRT TV repair Anonymous Wed Apr 4 21:35:09 2018 No.1363118 [Reply] [Original]

I picked up a couple of broken CRT TVs recently and I'm looking to fix them but it's hard to find useful info online between boomers losing their remotes and normies afraid of getting zapped to death. The models I have are a Zenith C27A24T and RCA F19426. I found a blown cap in the RCA but the whole board is drenched in cat piss. Probably just going to rinse that in vinegar and alcohol. The Zenith remains a mystery to me but probably still a cap, just not visibly obvious.

Zenith symptoms:
>whistle when plugged in which rises in frequency until inaudible
>press power button and the TV charges up and almost turns on then flashes off
>power button does nothing until replugged
>replugging makes a dull popping noise

RCA symptoms:
>plugging in causes a deep wub sound which seems to echo in the vaccuum
>does not power on at all when button pressed
>takes several dozen minutes for replugging to cause wub noise again

Wondering if anyone has any advice or information.

Pic is the RCA.

>>

Anonymous Wed Apr 4 22:39:10 2018 No.1363161

>>1363118
Zenith has a problem with the high voltage flyback circuit. Could be out of spec caps could be ic could be a bad inductor or any other number of things.

RCA I'd start probing the power supply test points and check rail voltages. I bet one of them is low or probably fluctuating.

The HV circuit is no joke and could actually kill but you know that so try not to fuck up.

>>	Anonymous Thu Apr 5 12:58:40 2018 No.1363512 >>1363118 This is the best problem description I've ever read. Kudos.

>>	Anonymous Thu Apr 5 18:05:32 2018 No.1363734 >>1363512 Indeed. This is refreshing. Thank you for posting. Why refurb the CRTs? The high voltage circuits are potential for other fun stuff.

>>

Anonymous Fri Apr 6 00:38:14 2018 No.1363998
File: 318 KB, 2550x1651, ZENITH-LG CN-27A24.pdf-1.png [View same] [iqdb] [saucenao] [google]

>>1363734
They're candidates for carrying to fighting game tournaments since they're much smaller and lighter than my 34". In the mean time they'd make good dedicated retro console screens.

Although if they end up fubar I can definitely find another use for high voltage.

>>1363512
Thanks, I worked as an electronics lab tech in the past. Just not on TVs.

>>1363161
I found this diagram which claims to be the Zenith. It's tough to match up to the board though as I'm much more accustomed to modern PCBs.

>>	Anonymous Sat Apr 7 00:46:05 2018 No.1364513 >>1363118 I think there is a crt general in the retro games board

>>

Anonymous Sat Apr 7 18:05:08 2018 No.1364846

>>1363161
>The HV circuit is no joke and could actually kill but you know that so try not to fuck up.
The HV running through these things can bite you pretty good, but is actually very unlikely to be deadly unless you've already got some sort of heart condition or otherwise.

The only area that could actually kill you is the power supply, with the large ass line filter caps.

>>	Anonymous Sat Apr 7 19:32:26 2018 No.1364891 what the hell is a CRT TV?

>>	Anonymous Sat Apr 7 19:55:13 2018 No.1364898 >>1364891 Cathode Ray Tube TeleVision

>>	Anonymous Sat Apr 7 20:21:30 2018 No.1364909 >>1364898 yeah but what is it

>>	Anonymous Sat Apr 7 20:28:53 2018 No.1364910 >>1364909 Remember the big assed tv that your grandparents had, the one with the back that stuck way out in the back instead of being a flat screen? It's that. Some of us remember when our family got their first one of those in color.

>>	Anonymous Sat Apr 7 21:19:40 2018 No.1364919 >>1364910 lol what. is this some meme or something? no such thing

>>	Anonymous Sun Apr 8 16:00:03 2018 No.1365374 its a CRT it belong in an electronics recycling center

>>	Anonymous Sun Apr 8 16:02:48 2018 No.1365379 >>1364910 I was talking to a much younger cousin the other day and it came up that the TV I used as a child had a button on it to switch from b/w to color. He didn't believe me.

>>	Anonymous Sun Apr 8 18:46:44 2018 No.1365490 >>1365374 >throwing anything away >ever nu-/diy/ pls go

>>	Anonymous Sun Apr 8 19:02:40 2018 No.1365499 >>1365379 Cracking me up, Anon... Ask said cousin if they know what a busy signal is. I've had teens tell me that there must be something wrong with the system because it didn't just go right to voicemail.