Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

[lookimback]

My newest project is a Sony Bravia KDL-40SL140. The picture is great at first but after about 10 minutes it fades out. I opened it up and can't see any physical signs. All the TABs look fine and applying pressure to them does nothing. I also tried freeze spray on the screen. No effect. I disconnected the ribbon cables from Tcon and reconnected them. Still no effect. Is it safe to say its probably the Tcon? Also, the Tcon has rubber pads on 2 chips. I know these are probably for heat transfer. Can these be removed and applied to a new board or should they be replaced? Also, what ar the pads called so I will know what to look for? Any help appreciated, thanks.

[budm]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

Like it has too much brightness so the picture is washed out, if it it, then more likely to be problem in GAMMA ref voltage due to bad GAMMA REF IC on the T-CON board.
For example:
https://www.badcaps.net/forum/showth...mma#post304275

[lookimback]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

@BudM, Funny, I was just reading one of your posts elsewhere in this forum about same problem. Also read your LCD TV and Monitor troubleshooting guide the other day. Found it to be very informative and very easy for a novice, such as myself, to understand. Thank you for that.

Now, I think you are talking about the AS15-F chip. Am I correct? I've pretty much given up on replacing the entire TCON board because a brand new one is way too expensive and a used one could, and probably will, end up doing the same thing eventually. My intention is to fix the set and sell it but I need to know it will last. From what I understand, this is a factory defect with that chip.

So, my next question. What do all the numbers on the chip mean?

Line 1.) AS15-F
Line 2.) 0823BG
Line 3.) B8312190

I can find dozens of suppliers for original AS15-F chips but the second 2 lines don't match mine. Also, I don't think I want an "original" because I would assume it probably has same inherent defects. Is there a chip that replaces the AS15-F? Sorry for so many questions.

[budm]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

Its the AS15-F that you need to get, the other lines are for Date code and Manufacturing site, etc. So does it use the AS15 on this board?

[lookimback]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

Yes, its the AS15-f. From searching I've determined that the actual part number is EC5575-F. I'm trying to locate a US supplier but having no luck. Ebay is still not an option, maybe in a couple days, I hope. I'm just not too comfortable sending money to companies in China, or many other foreign countries for that matter. No offense to any foreigners intended.

Edit: I'm also wondering about removing the old IC without damaging the board. I have a good soldering iron and desoldering braid but should I get a heat gun as well? As for soldering the new chip, I used to work for a company which made light fixtures and lighting controls and was professionally trained so I shouldn't have a problem there.

[truep]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

Unless you have the correct tools, don't try to replace the chip. get a replacement TCON. What is the number on the sticker on the board?

[lookimback]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

55.40T02.C08 its almost impossible to find though. Its extremely expensive when you can find it. I wouldn't chance buying a used one since its such a common problem. I'll buy whatever equipment I need to replace the chip. I'm lookin at heat guns now. Its something I will need regularly anyway. I could also just clip the contacts and remove them one by one. They're so small though.

Edit: OK, I just ordered a Kendal 852D++ hot air rework/soldering iron station from Amazon. Only $91 dollars.

[lookimback]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

Well, I couldn't find the as15-f chips in the US, aside from Ebay, which I still can't use. Ordered 10 of them from China. $15 and free shipping. Shipping could take 15-26 days though.

[lookimback]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

Well, good news. My eBay account has been reinstated. They thought my account had been hijacked and needed documentation to prove my identity. I was so lost without them for a whole month. Now my hobby is going to go into high gear.

[lookimback]

Re: Sony Bravia KDL-40SL14. Picture fades to white after about 10 minutes.

Well, my AS15-F chips arrived today. I soldered one of them on the board and got it right on the first attempt. TV is working fine now. I didn't have any trouble getting the old chip off the board. I used a hot air rework station that I bought off Amazon. This was my first time using it and it worked great. I can't imagine replacing the chip without one.

To anyone that's going to attempt to replace the chip themselve. If you don't have a rework station I would suggest that you clip the legs off the chip and remove them one at a time. When putting the new chip on, use lots of flux. You can clean the board after with isopropyl alcohol and a soft toothbrush. Also get a good magnifier. At least 10x. These chips are small and proper alignment is crucial. Also the magnifier is good for making sure you don't have any terminals bridged. Finally, take your time. It took me about a half an hour just to get the chip lined up and 2 corners soldered in place.