Strange Hyundai TV issue - Page 1
Forum section: electronics / repair

author: Srbel
author_rank: Frequent Contributor
timestamp: January 22, 2016, 07:23:57 am
content: This happened 3 times in the past couple of weeks. It didn't happen before. TV is around 10 years old. I will post the exact model number when I get home, if needed.So, when I press ON button on remote, when everything is working as it should, TV stand-by LED turns off and TV turns on. There is a sound of CRT turning on (at the moment of pressing the ON button).But, when this strange issue appears, it is like this: Press the ON button on remote, the LED turns off, the CRT sound is heard, but there is no picture nor sound at all. If I press OFF button on remote, LED turns on (as it should), and TV is off. I then press the ON button, and same thing. LED turns off, CRT starting sound is heard, but no picture nor sound. No matter how many times I repeat this, same result.But, when I unplug the power cable, press the ON/OFF button on the TV itself twice (to turn it off and on), then plug the power cable back, and then press ON button on remote, TV turns on as it should (LED turns off, CRT sound it heard, picture and sound appears).What could cause this?

author: tautech
author_rank: Super Contributor
timestamp: January 22, 2016, 07:49:51 am
content: I'm thinking bad caps.

author: Srbel
author_rank: Frequent Contributor
timestamp: January 22, 2016, 08:06:50 am
content: I thought so too, but when the power is cycled (pulling the plug, discharging the capacitors, and getting power back), it works again. So, I don't think it is caps (ripple issue).If I have time, I will open up the TV and check the caps during this weekend.

author: tautech
author_rank: Super Contributor
timestamp: January 22, 2016, 08:43:37 am
content: Quote from: Srbel on January 22, 2016, 08:06:50 amFor a while, right?I still suspect caps.

author: Srbel
author_rank: Frequent Contributor
timestamp: January 22, 2016, 08:49:13 am
content: It works until I turn it off (in a meaning that it does not shut down by itself). If I turn it on again, it works as it should.But in a week or so, I have to cycle the power again to make it turn on. After that, it is turning on and off normally.How would this make failed caps work for a week? I cycle the power, and suddenly, no excess ripple? I don't get it...

author: DmitryL
author_rank: Regular Contributor
timestamp: January 22, 2016, 11:52:08 am
content: .. it might be crackled solder joints on TV PCB. They produce whole bunch of funny effects due to intermittent contact.

author: Srbel
author_rank: Frequent Contributor
timestamp: January 22, 2016, 12:11:10 pm
content: I don't think so. I did not have to bump the TV in order for it to start working again.Power cycling cannot temporarily fix cold solder joint. :/

author: tautech
author_rank: Super Contributor
timestamp: January 22, 2016, 06:36:03 pm
content: Quote from: Srbel on January 22, 2016, 08:49:13 amHow do you know the ripple is not excessive?Have you had it apart?Quote from: DmitryL on January 22, 2016, 11:52:08 amSeen this too.Think thermal cycling and fine cracks.

author: Srbel
author_rank: Frequent Contributor
timestamp: January 22, 2016, 07:24:31 pm
content: No, I will take it apart tomorrow or the day after.

author: Srbel
author_rank: Frequent Contributor
timestamp: January 23, 2016, 02:42:35 pm
content: Well, I have opened it up, and there is nothing obvious. None of the caps look bulged, no solder joints look cracked.P.S. Model is TCV21K6550P.P.S. Some photos:https://www.dropbox.com/s/jssdnvopyzm8qio/IMG_20160123_152625.jpghttps://www.dropbox.com/s/1jtazfeednp8o0a/IMG_20160123_152643.jpghttps://www.dropbox.com/s/4mkb2jsndzg5uk3/IMG_20160123_152707.jpghttps://www.dropbox.com/s/eb08nex4n6386nz/IMG_20160123_152730.jpg

author: Rasz
author_rank: Super Contributor
timestamp: January 24, 2016, 02:37:05 am
content: 2005 crt?recycle

author: Srbel
author_rank: Frequent Contributor
timestamp: January 24, 2016, 08:27:26 am
content: OK, let me just play my whole salary for a new TV, because this one is from 2005...