2008 Samsung HL61A750 LED DLP owners thread and FAQ - Page 549 - AVS Forum | Home Theater Discussions And Reviews
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post #16441 of 16451 Old 01-26-2017, 08:04 PM
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Also page 4-2 service manual. They seem to say replace DMD board a lot early on. What is third box down in flow chart: Is LED for illumination off referring to? Is that the LED that is on the DMD board? I have a light on on my DMD board.
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post #16442 of 16451 Old 01-27-2017, 01:39 AM
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Quote:
Originally Posted by Mikes2cents View Post
Also page 4-2 service manual... What is third box down in flow chart: Is LED for illumination off referring to?
That is confusing; I would take it to mean the 3 Phlatlight LEDs that create the picture.

Did you ever get voltage readings on the 24 pin connector?
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post #16443 of 16451 Old 01-27-2017, 10:02 AM
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Quote:
Originally Posted by cosmicvoid View Post
That is confusing; I would take it to mean the 3 Phlatlight LEDs that create the picture.

Did you ever get voltage readings on the 24 pin connector?
Yes using pin 23 for ground I measured 11.9 on pin 24. When I attempted to go further in I shorted out on a heat sink cooling fin so aborted the operation for the night. Not a fan of sparks. Next plan is to remove everything from the set so I can access everything from the top right behind the empty set without trying to be a brain surgeon in tight confines. This will give me a opportunity to inspect all the components as well.
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post #16444 of 16451 Old 01-27-2017, 05:29 PM
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Quote:
Originally Posted by stanman2242 View Post
No! It is NOT the main power supply.
If it was the main power supply it would not even turn on.
It is the BP96-01726B SUB LED pcb.
That is the board that is on the right side of TV looking from back.
These boards had poorly manufactured capacitors on them from the factory
and eventually almost always fail.
I see perhaps 2% failure of main power board at the most based on 200+ TV samples.
The SUB board is the first thing to try because of the high failure rate.
For your problem I would say 95% of the time it is SUB LED board.
Well at this point I am going to have to say Stan is the man. I checked the 24 pin main and got the expected voltages just not exactly how I expected to get them but I suspect that is because I used the same pin 23 for ground. As I mentioned I removed everything outside the back of the TV and was able to test that without trying to be a contortionist. Then I separated the components and cleaned them up again for inspection. The 450V capacitor on the sub-SMPS looked ever so slightly bulged and a couple of the 25V ones do not look as concave as the others. Keep in mind none are bulging but I suspect they may not need to since they should be flat or be slightly concave. Reinstalled because I wanted to be sure I was where I thought I was and there you go...three power cycles and all three front leds flashing.
So I am going to order some caps to replace the big ones on the sub-SMPS. maybe even the smaller caps while I'm at it. Hell I almost want to replace all the caps on the main SMPS since I'm doing all this and have everything out. Thoughts? For me I feel fix the sub-SMPS and if all works then replace caps on main just because this is my luck if I try all and no love then I'm scratching my head. Keep in mind this is a spare time fun project for me because I have logged a lot of hours with that Sammy and I am attached somehow to it. I can't let it go that easy. She's like a girlfriend that was always there in my man cave and she never talked back or told me what to do.
Anyways, thanks for all your guys help and if I am going down the wrong road please let me know. As a side note/question, will a HL67A750 light engine work in a 61" unit. I see they have different part numbers but wonder if the only difference is simple geometry, ie bigger chassis. There is one on sale on evilbay and for that price it is worth it just for the DMD board, driver and leds. Thanks again everyone.
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post #16445 of 16451 Old 01-27-2017, 07:08 PM
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Quote:
Originally Posted by Mikes2cents View Post
As a side note/question, will a HL67A750 light engine work in a 61" unit. I see they have different part numbers but wonder if the only difference is simple geometry, ie bigger chassis. There is one on sale on evilbay and for that price it is worth it just for the DMD board, driver and leds.
I guess the difference would also be in the optics, to spread the image out to a larger screen.

I have seen your symptoms caused by either or both of:
a) the large caps on the main-smps (the 300v output folds back under load).
b) the caps on the sub-smps (the big one &/or the 4 medium ones).
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post #16446 of 16451 Old 01-27-2017, 07:32 PM
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Quote:
Originally Posted by cosmicvoid View Post
I guess the difference would also be in the optics, to spread the image out to a larger screen.

I have seen your symptoms caused by either or both of:
a) the large caps on the main-smps (the 300v output folds back under load).
b) the caps on the sub-smps (the big one &/or the 4 medium ones).
Thanks friend. I just ordered the big caps for the sub-SMPS and if that doesn't work I will buy something from stan that is reported to be known working.
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post #16447 of 16451 Old 02-05-2017, 04:19 PM
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Just popped in to say that my 67" inch is still going strong. I bought it in May 2008, and it never has needed a single repair... even with heavy use. I'll be replacing it this year with a 2017 4K model, but this has been a fine tv with a great picture.

I'm glad to see people are still enjoying theirs too.
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post #16448 of 16451 Old 02-07-2017, 06:46 PM
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I finally did it! Replaced the DLP chip I bought a few weeks ago. Took a little over an hour. I had the light engine almost all back together and remembered I forgot to check the chip for dust. Sure enough there was a speck on it. I did use thermal paste, the pad that came in the installation kit ripped in my hand. I did however have 1 thing happen which I hope will not be an issue down the road. One of the spring screws broke and a threaded piece of it is stuck in the board. There are only 3 of them in there now. What are my odds of trouble? Other than that very easy to replace.

There was not much dust at all and my caps were NOT bulging!

Last edited by Dominic26; 02-07-2017 at 06:48 PM. Reason: Spelling
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post #16449 of 16451 Old 02-08-2017, 12:19 AM
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There is no difference in the optics!
I have taken light engines from 50" and put in a 67".
Everything works perfectly, focus is fine and picture fills whole screen.
I guess that is the reason that when I put 61" and 67" cases out for the trash
they keep vanishing before the trash guy shows up.
The HL50A650 guts will go right in a HL61A750 and you have an inexpensive BIG TV.

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post #16450 of 16451 Old 02-08-2017, 09:05 AM
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Hello, I've been dealing with a sub power board issue ( tv just clicks and 3 leds in front, no turn on). Trying to figure out which caps are bad. Can anyone tell me what the readings should be on the 9 caps on the board, thanks . I've been getting regular use out of tv by using a blow dryer to heat up the board (about 30 seconds on high) push power button and starts right up like new! What component is using the heat to be able to work and turn on tv? I'm assuming the caps but just want to verify to make sure I'm on the right track. Thank you
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post #16451 of 16451 Old 02-08-2017, 01:51 PM
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Don't read them, just replace them replace 25 volt with 35 volt and
replace the 450 volt.

One reason you cannot read the four 25 volt caps is a little known fact that they
are all connected together in parallel.
Surprise, surprise!

Readings are meaningless without removing the caps and if you are going to do that
you might as well put new ones in.

I replace a lot of them.
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Last edited by stanman2242; 02-08-2017 at 02:09 PM. Reason: Add photo
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