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Old 08-09-2018, 01:58 PM   #1
yohnsee
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Default Samsung LE40B530 - iR doesn't work

Hello everyone,
I am slowly going crazy over a problem, please help me out, if you can.
Long story short: I got a LE40B530 that had a mainboard issue. Power supply checked out fine, so I decided to buy a replacement main.
I bought a mainboard from a local guy, but he told me that this board may not function properly. He is no expert, he removed it from his broken screen set, sold it to someone, who sent him back because it "froze". His tv was also a LE40B530. Only difference is that his mainboard is BN94-02710T, my original was BN94-02710M. For me they look identical, and googling what the difference is between the "T" and "M" did not gave me any results.
Anyway, I gave it a try. My set turns on, works perfectly fine, until a few minutes pass by, then it doesn't react to the remote controller.
It receives the signal, the standby led blinks but nothing happens.
I followed the path of the signal, it goes into a chip named IC3003 (WT61P8) and I believe that the problem is related to this IC. When the tv is on for about 5 minutes, this IC gets warm (it doesn't get hot no matter how long the set is on) and the set no longer responds to the remote. BUT if I cool down this IC, it works again! More strange things are coming: in this state, the power button still works, but not as intended. If I push it, the standby led blinks, that it received the code, then I wait about 2 seconds, and it turns off. But not as it should, because on a normal shutdown it plays a melody. In this case it just turns off. I attached photos of the main and the suspected IC.
In addition, the set looks to operate fine from the buttons on the side. The buttons are wired to the same IC, but on different pins.
Any idea, what should I measure? Where should I look for the problem?
I've tried so far:
-change the eprom between the 2 boards
-change this IC between the boards (it got worse)

382533328-Samsung-La32b530p-La37b530p-La40b530p-La46b530p-La32b530p-La26b450c4-La32b450c4mxxs-Ch.pdf

P80807-235557.jpg

P80807-235602.jpg

P80809-154358.jpg

P80809-154339.jpg

P80809-140631.jpg
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Last edited by yohnsee; 08-09-2018 at 02:01 PM..
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Old 08-09-2018, 03:42 PM   #2
budm
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Default Re: Samsung LE40B530 - iR doesn't work

If you suspect that the IC failed when it is worm up then you should try usiing freeze spray or canned duster upside down to cool the IC and see what happen.
You can repeat the problem, correct?
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Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

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TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Old 08-09-2018, 04:01 PM   #3
yohnsee
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Default Re: Samsung LE40B530 - iR doesn't work

Quote:
Originally Posted by budm View Post
If you suspect that the IC failed when it is worm up then you should try usiing freeze spray or canned duster upside down to cool the IC and see what happen.
You can repeat the problem, correct?
Hello budm, thanks for coming by.
Yes, I may forgot to mention, that I used freeze spray to cool the Ic down, and the remote started to work again. I can repeat it as many times as I want to. This chip has programmable memory, and my fear is that even if I buy one from eBay, I can't get the code written into it.
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Old 08-09-2018, 05:31 PM   #4
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Default Re: Samsung LE40B530 - iR doesn't work

freeze and download code if programmed one not available
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Old 08-09-2018, 08:57 PM   #5
yohnsee
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Default Re: Samsung LE40B530 - iR doesn't work

Quote:
Originally Posted by petehall347 View Post
freeze and download code if programmed one not available
Yeah, that crossed my mind too. I have a TL866 at home, unfortunately that can't handle it. I am thinking of getting an other programmer also, but I don't know which.
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Old 08-10-2018, 10:52 AM   #6
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Default Re: Samsung LE40B530 - iR doesn't work

Can you transfer the chip from your old board across to your new board?
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Old 08-10-2018, 11:24 AM   #7
yohnsee
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Default Re: Samsung LE40B530 - iR doesn't work

Quote:
Originally Posted by syaoran123 View Post
Can you transfer the chip from your old board across to your new board?
Yes, and I already made it twice. The old one refuses to work even sooner. So at this point I think, I may be so unlucky to get 2 ICs with the same problem, OR the problem is on the other part of the board and somehow related to this chip.
Anyway, I wanted to fix it as soon as possible, so I ordered a 100% working mainboard. I will be very curious, when it arrives, I will make counter measurements, maybe it will tell me what the difference is.
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Old 08-11-2018, 11:28 AM   #8
syaoran123
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Default Re: Samsung LE40B530 - iR doesn't work

Oh you mentioned you moved the IC across in your original post. Sorry for asking.

Btw, the Samsungs normally take 2 sec to respond to power off commands on the remote, don't they? And the melody could be set to ON/OFF using the screen menu.
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Old 08-12-2018, 06:10 AM   #9
yohnsee
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Default Re: Samsung LE40B530 - iR doesn't work

Yes, you can set the melody. BUT this happens, when it is set to play it. I am not missing or anything, I was just thinking this gets us to locate the problem. I have a feeling, this is some kind of weird issue related to the IC's internals. As I wrote, I have already ordered a working mainboard, but being curious about this problem, also ordered an IC. Will look into it when they arrive. One more addition: having absolutely no other idea, I refreshed the solder joints around this IC. Resistors, capacitors, everything. When I got to the 24MHz crystal, the working time of the set significantly increased. I have never seen a crystal go bad, but at this point, I can imagine everything
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