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Post by mastertech on Oct 29, 2017 9:44:04 GMT -5
Not a big fan of in circuit cap testing. Using my Peak ESR+ ESR70 most caps actually tested way high. That said, these came back reistering low or leaky in circuit C163 330 uf C165 330 uf C603 10 uf C600 10 uf C1019 100 uf When you say "way high" and "registering low" do you mean cap value or ESR reading? |
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howie
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Post by howie on Oct 29, 2017 14:46:40 GMT -5
Way high capacitance. ESR's were low. Also not quite sure of the effect of using clips and push pins to probe the in circuit caps
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Post by mastertech on Oct 29, 2017 16:52:04 GMT -5
In circuit capacitance testing is worthless. Rarely accurate. Only ESR can be tested in circuit but still should be verified out of circuit, but only if it shows bad.
Couple tests you can do to rule out some things. When tv not working and all boards connected test for voltage at pin 22 of harness from PS to main. Should be 0v. If it is 5v then there is a problem.
Also on the small board with the power button on it there is a 4 wire harness. Test for 3.3v across pins 1 and 2 and then test across pins 3 and 4.
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howie
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Post by howie on Oct 29, 2017 17:39:59 GMT -5
Showing 4.13V on pin 22 The small board is showing 3.3v at 1 and 2 and 3 and 4. I don't think it's a panel issue as it won't power up with the ribbon cables detached. Both back lights come on when the PS is jumped out. Unplugged back lights to make sure they were not pulling to much. Still think it's a bad main board.
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howie
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Post by howie on Oct 29, 2017 17:42:19 GMT -5
There is 2 reset buttons on the main board. What's their function and how do you use them (I know you have to push them)
I'm guessing that voltage on pin 22 is somehow blocking the power supply from coming on??? Can you cut it for a quick test???
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howie
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Post by howie on Oct 29, 2017 18:11:41 GMT -5
So curiosity got the best of me. Wanted to know if the 5 volt error signal came from the main board or the power supply.
So I cut the wire and re-probed The 5 volts is coming from the power supply. When cut, zero volts at pin 22 on the main board but it still doesn't power up
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Post by mastertech on Oct 29, 2017 18:41:07 GMT -5
It looks like the 5v error comes from the inverters for the backlights. And the 5v is normal when in standby and tv not running. Backlights have to be on for the voltage to go to 0v. So I would guess that if you jumped the PS with the 2 resistors the error line would go to zero. So I would guess the tv should at least turn on for a second or 2 before shutting down if there was a problem with this line.
Let me see what I can find on those reset buttons.
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Post by mastertech on Oct 29, 2017 18:55:56 GMT -5
SW100 is microprocessor reset and SW1100 is video processor reset. There is no other info on them. It probably wouldn't hurt anything to press them but I would think the tv would have to be working for it to do anything.
What is the status of the tv now, working or not?
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howie
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Post by howie on Oct 30, 2017 16:56:33 GMT -5
Status, dead Don't have the caps to replace the ones suspected bad and running out of time to deal with it. Ordered a replacement new main board and hope for the best
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Post by mastertech on Oct 30, 2017 17:51:20 GMT -5
If you want to try something just for fun, get a piece of wood or a pencil and push on ic100 while trying to turn it on. I believe that is a BGA, I think?
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howie
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Post by howie on Nov 5, 2017 17:00:22 GMT -5
I can't seem to get a break. I only opted to fix this TV because it has 4 HDMI inputs, 2 component and 2 composite inputs
All of which are being used. Also, the set is controlled via the serial port from my Crestron system. I put the new main board in and it powered right up. Everything looked normal until I plugged in all the inputs. Then I discovered that HDMI 1 was dead. TV switches to it but it doesn't connect. Tried other sources and cables with no luck. This is a new board. Not a used one. I sent a message to the seller this morning. Hope he has another to exchange it with.
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Post by mastertech on Nov 5, 2017 18:04:41 GMT -5
Have you tried doing a master reset of that new main board just in case it was tested in another tv and settings changed. Also make sure that "Simplink" is turned off in the menu. Also saw this in the manual:  |
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howie
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Post by howie on Nov 5, 2017 21:07:06 GMT -5
How to perform "master reset"?
The cable that doesn't connect in HDMI 1 works in HDMI 2
Don't recall seeing "simplink" in the menu. Will go look for that now.
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Post by mastertech on Nov 5, 2017 22:02:56 GMT -5
The cable that doesn't connect in HDMI 1 works in HDMI 2 I realize this but have found in the past that just because something works in 1 port doesn't mean it will work in another. Just sayin.  There is a picture reset in the menu section. May not help much but worth a try. See image below. There is also a service menu section but there is no information on what is in it in the documents I have. There maybe a master reset in there. Also see below.   |
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Post by mastertech on Nov 5, 2017 22:06:45 GMT -5
Looks like there is also an input block in the menu section. Make sure your HDMI 1 input is turned on.  |
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