Sony KDL40S2000 TCON board issue...

[budm]

Re: Sony KDL40S2000 TCON board issue...

He needs to show good close up pictures around the connector of the T-CON so we can see this fuse. I never seen T-CON with resetable fuse before.

[tom66]

Re: Sony KDL40S2000 TCON board issue...

He needs to show good close up pictures around the connector of the T-CON so we can see this fuse. I never seen T-CON with resetable fuse before.

I am suggesting the fuse was inadvertently replaced with a resettable fuse instead of a permanent fuse.

[budm]

Re: Sony KDL40S2000 TCON board issue...

That is what I think or just very poor soldering joints, pictures will tell us what is gong on.

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

That is what I think or just very poor soldering joints, pictures will tell us what is gong on.

here a picture of the tcon board fuse that has been replaced..
hope it can helps

[tom66]

Re: Sony KDL40S2000 TCON board issue...

Hmm -- hard to tell -- I have seen orange resettable fuses before -- however, the best way to tell would be to install it in the TV, measure voltage on top end with TV working, then measure it as it starts giving problems or gets worse and see if there is a drop. Actually, measure the bottom too, because then we can rule out PSU, main board and cabling.

[budm]

Re: Sony KDL40S2000 TCON board issue...

Agree with TOM suggestion in post 25, that will be the easiest test to do.

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

Hmm -- hard to tell -- I have seen orange resettable fuses before -- however, the best way to tell would be to install it in the TV, measure voltage on top end with TV working, then measure it as it starts giving problems or gets worse and see if there is a drop. Actually, measure the bottom too, because then we can rule out PSU, main board and cabling.

I see..Just to be more precise:
- the fuse is not orange but dark brown
- the TCON board is already installed in the TV

In order not to damage the TV or myself, i want to be sure and avoid any mistake, so I intend to do as follow:
- I put the multimeter on DC 200
- I have to find a negative point on the TCON board
- I put the black tip of the voltmeter on the negative (on the board) and the red tip at the top end of the fuse and see which is the value when the TV works well
- I repeat what above when the TV starts going wrong and see if there is a difference
- I repeat the measure with the same negative but with the bottom end of the fuse to see if there is a voltage drop (before and after TV showing the problem)

Now the hardest part.... how can I find a negative point on the board?? May I use any other negative point of the TV (for example the negative of the power supply board, that it's easier to find??)
Sorry for my "stupid" questions but I want to be sure not to do any other damage

[retiredcaps]

Re: Sony KDL40S2000 TCON board issue...

Now the hardest part.... how can I find a negative point on the board??

I normally use a ground screw closest to the measuring point. That is, you can use a ground screw on the t-con.

[tom66]

Re: Sony KDL40S2000 TCON board issue...

And setting to DC20 will give one extra digit of resolution.

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

I normally use a ground screw closest to the measuring point. That is, you can use a ground screw on the t-con.

Ok, I'll check it out and let you know the readings

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

Something strange on the fuse....Below the readings:
TV working properly:
Black on TCON grounded screw and Red on Fuse BOTTOM = 4.94 VOLT
Black on TCON grounded screw and Red on Fuse TOP = 4.50 VOLT

TV NOT working properly:
Black on TCON grounded screw and Red on Fuse BOTTOM = 4.98 VOLT
Black on TCON grounded screw and Red on Fuse TOP = reading varyimg from 4.07 to 4.70 VOLT !!!!
A strange think happens when I did a second readings...I've noticed that pushing with the red pin of the tester on the bottom soldering of the fuse the problem disappeared..!!!! So I tried to use just the red pin not attached to the tester..and the problem fix...
It has to be a poor/cold soldering of the fuse on the TCON )))))))
May I try to fix the join by just putting the solder tip on the joint or do I have to desolder the fuse and solder it again?!?!

[tom66]

Re: Sony KDL40S2000 TCON board issue...

I would suspect a failed fuse -- simply replace the fuse for longest reliability.

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

I would suspect a failed fuse -- simply replace the fuse for longest reliability.

But how can I find the fuse value or type?
Can you help me in identifying the right one?

[tom66]

Re: Sony KDL40S2000 TCON board issue...

Since the fuse has been replaced incorrectly, and given the board takes in 5V (usually 2.5~3A at 5V), I'm going to estimate a 4A fuse.

http://www.digikey.com/product-detai...84-1-ND/615045

[lenny1972]

Re: Sony KDL40S2000 TCON board issue...

Ok. Do you think that I have to take a SMD fuse ( like the one you suggested me) or can I take something bigger in order to be easier to solder??

If a SMD component is needed can I buy this product?

http://www.ebay.it/itm/Fuse-10-pcs-S...1#ht_500wt_689

It seems to be the same item of your link...

When soldering the fuse on the board do I have to be aware of something specific (i.e. solder temperature, fuse position, etc..)?? Sorry but I'm really a newbie...