tv not turning on, some caps replaced same error

[odgaf]

hey people happy xmass and new year etc


i have a tv soniq e40s12a that will turn on only sometimes, i checked the green caps and replaced ones that were failing still same problem

i then checked mains filter caps and 2 are 33uf, but the bottom one was only 30 uf, i then checked the voltage across them and i am getting 220dc in standby, which rises to 270v when set turned on which as i understand means there might be a boost problem

total noob here but i have all tools i need to carry out suggestions

i have inked the green caps i changed, inked the 30uf cap and also the heatsink near the mains filter caps is giving out serious heat as soon as i turn on, within a few seconds its too hot to touch

hoping one of you brainboxes can point me in right direction, so the tv has standby, comes out of standby to turn on, backlights come on for a second, then off, no picture or sound, its just hangs like that and goes back into standby after about 30 seconds, sometimes it will boot and operate normally for days but its getting hard to turn it on now

diodes and fuses are ok i think

[budm]

Re: tv not turning on, some caps replaced same error

OK, you have 3 main filter caps, the black one laying on the side.
Are you saying you only get 220VDC in standby?
That cannot be right, the Voltage on the main filter caps should be yoUR coming AC X 1.414, your country AC Voltage is 230~240VAC so you better recheck your meter and your measurement method. What did you use for your meter GND?
"i have inked the green caps i changed, inked the 30uf cap and also the heatsink near the mains filter caps is giving out serious heat as soon as i turn on, within a few seconds its too hot to touch" Cap will get hot and blow up if it is installed with wrong polarity or over Voltage being applied.
BTW, where the make and model of this TV you are working on?
Where are the pictures of the whole backside of the TV showing all the boards?

[odgaf]

Re: tv not turning on, some caps replaced same error

bah sorry its a soniq e40s12a

hmm strange readings on voltage, i just repeated test 3 times and im now getting 203vdc on all 3 mains caps using both chassis ground hole and the ground wire i get same results, im in australia

soon as i fire the set up all 3 caps stop boosting at 270vdc

im putting black probe on chassis red probe to cap leg soon as i flick power to put set into standby the caps boost to 203, then when i turn set on they rise to 270vdc the backlight either flickers once or stays on for a second or so then goes off, occasionally the backlights stay on and set boots normally

here is full back pic

[odgaf]

Re: tv not turning on, some caps replaced same error

i triple checked the caps, and all have correct polarity

[budm]

Re: tv not turning on, some caps replaced same error

"hmm strange readings on voltage, i just repeated test 3 times and im now getting 203vdc on all 3 mains caps using both chassis ground hole and the ground wire i get same results, im in australia "
Well, you are working in the HOT SIDE of the circuit, you cannot use chassis GND for your meter reference. The GND ref. for your meter is the Negative leg of the main filter cap.