Toshiba tv blank screen

[vw1]

Nothing to do with welding but my Toshiba TV once switched on at the plug takes an age to come on . The small light indicator on the front flashes but pressing the button on remote won't turn it on straight away I could spend 5 mins pressing the remote and it will fire up.

Tv it's self has a button on the edge of unit you can press it and makes a beeb but again does nothing.

Took main board out but can't see anything strange no capacitors diodes that look swollen?

As said it does come on but of it own accord but can take from 5 mins to 45 mins to come on so it kind of works .

Any suggestions please ?

 

[hollow]

That green cap in the middle of the second pic looks goosed to me

 

[vw1]

So where can I get replacements caps flea bay ?

 

[hollow]

Yup. Amazon too sometimes.

 

[MattF]

So where can I get replacements caps flea bay ?

They'll probably sell full psu kits on there. Best replacing a portion of the caps if one's going.

 

[vw1]

How do id them ? By the numbers on the caps I take it ?

 

[MattF]

Their values are printed on the cap itself, both voltage & capacitance. Best off replacing with 105° caps.

 

[vw1]

No idea what 105 caps are but thanks again.

 

[voipio]

That green cap in the middle of the second pic looks goosed to me

As is the other green cap at far right of the same image.

105° caps are designed to operate at elevated temperatures - 105 degrees, as opposed to the 85 degree type that might be fitted. I can see that the green cap at far right of the second pic is shown as a 105° type in another pic.

 

[angellonewolf]

have you cheaked the price of a power board ?

 

[gaz1]

lcds suffer from over heat issues

also check the solder joints on them and you will find dry joints on the board hence why it takes an age to turn on until its warmed up

 

[ukracer]

I had a Panasonic that took an age to lock on...it took longer and longer until it stopping turning on all together.
My next door neighbour fixed it (tv engineer) and I think it was a relay..

 

[vw1]

have you cheaked the price of a power board ?

No not yet .

 

[angellonewolf]

No not yet .

if its an older tv id cheak ebay might get a board for 20/25 quid

my tv that was only 3 years old the board was 40 so not massive but the leds where bust as well and for the set of them was 60 so decided to bung it as that was 100 to a new tv

depending on what tv it was tvs 2nd hand are cheap realy so id not spend loads on repairing

 

[Seadog]

Small cap at the bottom in the first photo. The right hand one has blown. A classic PSU failure.

 

[Seadog]

That green cap in the middle of the second pic looks goosed to me

The green caps low ESR I seem to recall.

 

[vw1]

Yeah well tv was used for retro gaming and it's well over 10 year old I think. I just thought if easy fix (welding) in a few new caps etc I don't mind the giving it ago. Just hate chucking into skip if it's cheap enough to fix by myself etc.

I have all the soldering gear so no expense apart from replacement caps etc.

 

[gaz1]

even the big crt tvs used to suffer dry joints

the new pcb boards are even worse as the solder is so thin of a coat of coarse its going to break apart giving you a dry joint

 

[armalites]

Get yourself onto RS Components or CPC and just replace them all. Will only cost a few quid. Make sure you get them round the right way, they go off with a bit of bang if they are put in the wrong way. I remember seeing some board of soak test at my first job where someone new on the assembly line had put them in the wrong way, they all went off in quick succession.

 

[vw1]

have you cheaked the price of a power board ?

Yeah a replacement on evil.bay is £30 and 4 replacement caps £8.