Sony trinitron CRT wont turn on and relay clicking - Page 1
Forum section: electronics / repair

author: lucky.peic
author_rank: Newbie
timestamp: January 18, 2020, 04:05:46 pm
content: Hello, so i have Sony trinitron KV 21-C4D from 1998 that when plugged in relay clicks on and power meter shows that its using 24 watts and after 5 seconds just clicks off and power usage drops to 21 watts and nothing happens, it does not even make sound of tube turning on and no standby LED.This problem started way back when my parrents still used it many years ago, first it progressivly became harder to turn it on using remote when it was in standby overnight, it sometimes took 15 or 20 minutes if pressing power button on remote for tv to turn on, upon pressing power button on remote standby led would turn off (like it should) and relay would click and tube would make normal "bong " sound as it is starting up and within few seconds relay would click again and tv would be back to standbyThen we figured out that instade of putting it on standy at night it was better to just unplug it because then it would start up without issue when plugged in (this model of tv turns on immidatley instade of going to standby when plugged in) but after a while it became harder to tun it on that way too and when plugging it in it would turn on red standby LED then relay would click and led would turn off then relay clicks off and tv is back to standby wirh red LED on, it would then usually take few minutes of unplugging and plugging it in for it to turn on and it was progressivley getting worseNow many years later i want to use it for some of my retro consoles like PS2 but it most of the time no longer works at all, i can sometimes force it to turn on by heating it up trough vents on the side then it would slowlsy come back to life, at first when plugged in not even standby led comes one, just relay clicking then after some time led would start to come one for few seconds and then longer and longer until TV finally manages to start upI tought it was big 400 180uf volts CAP on PSU so i replaced it with closest value i had that was 400v 150uf but problem remains the same, when plugged in relay clicks on, no standby led, no sound of tube trying to turn on and after 5 seconds relay just clicks offI do plan on oredring all caps to recap it fully but i dont know if thats gonna fix it, is there anything else i could look at because i dont want to waste money on recapping if there is maybe something else deadTo me its wierd its taking 21 wats of power after relay clicks to off position because it isnt even in standby by that point so i dont know what could draw 21 watts of powerI apologize for my bad English and for long post but i really wanted to give detailed report on history of this issue just in case it makes any difference repairing this

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 18, 2020, 04:56:35 pm
content: It is very likely to be capacitor related, however re-flowing plenty of old solders first would be a good starting point, the odds are that just handling the PCB a few times you may have solders that are so badly aged components will be wobbling away and you'll have more problems to see to. Always look at hot and heavy components first.Download the Service manual for Sony BE-5 chassis.It isn't always worth the bother replacingallthe capacitors IMHO.I would start checking the electrolytics in the hot spots, all those close to heatsinks or power resistors.On PSU primary side make sure you check C610, C612, C614 near the STR-S6707 IC.

author: lucky.peic
author_rank: Newbie
timestamp: January 18, 2020, 09:28:13 pm
content: Quote from: shakalnokturn on January 18, 2020, 04:56:35 pmThanks for advice, i will try to reflow in the next few days hopefully (i do this as side project when i have some free time)I checked all caps and none of them are bulging or have obvious sign of failure, i only have multimeter and unfortunatley currently dont have ESR meter for caps so i cannot test them and will probably have to replace the ones that you menitoned to see if it works