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COBY LEDTV4626 not receiving power (dead set)    
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flashheatmvp3



Joined: 08 May 2015
Posts: 2
Location: Virginia

PostPosted: Fri May 08, 2015 6:36 pm    Post subject: COBY LEDTV4626 not receiving power (dead set) Reply with quote

I bought a broken TV from a friend with the idea to fix it up. When I bought it only the blue standby light worked, and after taking it apart and putting it back together it miraculously came on and worked perfectly... until I shut it off then it wouldn't come back on. Atleast this kinda told me that it wasn't an issue with the LED driver or t-con board since those are both connected to the panel itself. The issue had to be from power.

The next day when I went to try it again, now even the standby light had gone dead, like it wasn't receiving any power at all. Originally I believed it to be a power supply board issue, possibly a broken capacitor that just wasn't visibly defective. I tested it with a multimeter and didn't notice anything off, but still went ahead and replaced the power supply board. To no avail the power supply board didn't fix anything.

Only things left now are the main board or possibly the cable going from the PS board to the main board, shown in the pictures http://imgur.com/A/VZCD1 . I've continued to test it with a multimeter and have realized that everything seems to be reading normally but for some reason when I test the 12V on either side, it sparks a little bit. Anybody know if that could mean an issue with the cable?

http://i.imgur.com/hChqQPX.jpg Here is another picture of the main board. The rainbow colored cables connected to the top there go to the buttons on the side of the TV and the LED standby light. When I test those with the multimeter, if I connect it to the right one the little LED lights up like it is getting full power. I don't get how touching it with a multimeter is giving it power. Any help would be appreciated
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JTS1957



Joined: 21 Jan 2009
Posts: 2328
Location: Far, Far Away

PostPosted: Fri May 08, 2015 9:45 pm    Post subject: Reply with quote

What DC voltage(s) are Power On & 5VSTB reading? First, when the TV has just been plugged into wall outlet and second, when you press and release the power button (on the set or on the remote)?

Receiving a defective replacement Power board hasn't been ruled out.
You most likely obtained a 'New' (to you) power board from a place that supposedly pulls 100% fully working boards from a working TV right before Junior uses the screen for target practice.

Disregard last paragraph IF you obtained a NEW board through Coby / Coby authorized distributor.

Btw, your first picture link is: Zoinks! You've taken a wrong turn.
flashheatmvp3



Joined: 08 May 2015
Posts: 2
Location: Virginia

PostPosted: Sun May 10, 2015 10:04 pm    Post subject: Reply with quote

Sorry bout that first pic http://imgur.com/gallery/VZCD1/new that link should be working. And you are right about the Power On and 5VSTB giving me funky readings now. Sometimes power on reads 3.0 and the 5v reads 5.0, but it would often cut in and out, going down to 0. Also I noticed when I was measuring the 5VSTB it was causing the power board to buzz a little bit. The power button doesn't seem to be causing the fluctuations and I don't really have any indication it's doing anything at all
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