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dgentry516
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Dec 20, 2010, 2:07 AM

Post #76 of 84 (1102 views)
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Re: [Ron.M] Need Ron M [In reply to]	Can't Post

Ron

Ron

I have a reading from the Neg of C609 to one side of R613 and R618 but no reading from C609 to the other end of that resistor, R613 and R618.

I also have a reading from the Base of Q601 to one side of R613 and R618 but not the other side.

Appears to me that the reading stops at the resistor.

I'm sure I'm off base here but just wanted to share the information for whatever its worth.

Talk to ya tomorrow,
Don

Ron.M
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Dec 20, 2010, 8:28 PM

Post #77 of 84 (1091 views)
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Re: [dgentry516] Need Ron M [In reply to]	Can't Post

dgentry516;....

Stupid questions , sorry...
When you took those readings ,
The resistors ARE in circuit , i.e. soldered on the board ???
The last time you read their values , they were about 60 ohms each...
Remove & re-check them....
IF you still get the 60 ohm reading , then we may have a foil problem at one end of where the resistors are soldered in...
Looks to me that BOTH resistors are open....
Unusual to say the least....

Later...Ron.M.... Cool

...
Veteran & Retired TV technician

dgentry516
New User

Dec 21, 2010, 3:03 AM

Post #78 of 84 (1087 views)
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Re: [Ron.M] Need Ron M [In reply to]	Can't Post

Ron

The resistors ARE in circuit , i.e. soldered on the board ???

No.
They are 27.2 and 27.4. Don't ask me where the 60ohm figure came from. How I got that reading I don't know unless I didn't have my meter set right.

Installed the resistors back in….here is the readings you wanted.

Q601 to "HOT" ground with the red lead at the base....

Q601 center pin to neg C609=173.9

14.68M D621 to hot ground
14.64M D625 to hot ground
14.57M D624 to hot ground
(reading with power plugged in)

Thanks for your help!

Don

Ron.M
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Dec 21, 2010, 9:16 PM

Post #79 of 84 (1074 views)
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Re: [dgentry516] Need Ron M [In reply to]	Can't Post

dgentry516;....

There is a discrepency in this reading...
"""Q601 center pin to neg C609=173.9 """

With the 4 resistors I mentioned , the reading should be around 138.8 K ohms & not 173.9...Tooo high....
So lets try this;...
Connect the black lead to the case of C609......
Take a reading from the base of Q601....
Let the meter settle in if it is fluctuating....
Note the reading & whether you see a "K" or an "M" on the meter...
Then take a reading from the other side of R613/R618...
Note reading....
Then take a reading from the other side of R622...
That will read across R619...
Note reading....

Post all results....

BTW:....

Quote

14.68M D621 to hot ground
14.64M D625 to hot ground
14.57M D624 to hot ground
(reading with power plugged in)

....
Veteran & Retired TV technician

dgentry516
New User

Dec 22, 2010, 2:42 AM

Post #80 of 84 (1069 views)
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Re: [Ron.M] Need Ron M [In reply to]	Can't Post

I don't know why you did that ????
Those diodes are in the secondary & are to "chassis" ground & NOT "HOT" ground (OR the AC side)
AND , NEVER , NEVER read ohms with the set plugged in!!!
IF you go to the wrong place to take a reading in ohms with the TV plugged in, you WILL blow your meter....Guaranteed !!!

I don't know either. I know the diodes are on the secondary side. Why I did that? I don't know.

Here are the measurements.

Connect the black lead to the case of C609......
Take a reading from the base of Q601....
Let the meter settle in if it is fluctuating....

21.68k

Note the reading & whether you see a "K" or an "M" on the meter...
Then take a reading from the other side of R613/R618...
Note reading....
Then take a reading from the other side of R622...
That will read across R619...

I'm sure I did this all wrong. Getting frustrated with my inability to do something that should be simple.

I measured C609 to R618. 21.60k
To R613. 21.35k
To R619. 18.50k

Go ahead, tell me what a dumbass I am. Thanks for your patience.

Don

Ron.M
Veteran

Dec 22, 2010, 8:54 PM

Post #81 of 84 (1062 views)
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Re: [dgentry516] Need Ron M [In reply to]	Can't Post

dgentry516;....

I WILL NEVER call you a "dumdass"....

But , it's getting a bit on the futile side with this TV....
Here's the deal...
This TV has what's called a "closed loop" power supply.....
That means that the primary side is regulated by feedback from the secondary side....
The secondary side is regulated by the primary side which is getting feedback from the secondary side.....
See what's going on here ???...
So if there's a problem in the primary (which you have) , the secondary will not come up with those stand-by voltages....
Now , not only do you have a power supply problem , but , you also have a drive voltage problem to Q401....
And now there's no 130 vdc....
So it's gotten worse....
This TV requires a hands-on TV Tech...
Sorry to say that no matter how sharp your are , there is no way that we are going to post back & forth & fix this TV....
Way too complicated a problem....
My best advice would be to take the TV to or call a GOOD , REPUTABLE & HONEST TV Shop....
See if you can get a Free estimate & go from there.....
I wish you nothing but the best of luck.... Sly

....

A VERY Merry Christmas & a VERY Happy , Healthy & Prosperous New Year to you , your family & loved ones....

Later...Ron.M.... Cool

....
Veteran & Retired TV technician

dgentry516
New User

Dec 23, 2010, 12:58 AM

Post #82 of 84 (1056 views)
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Re: [Ron.M] Need Ron M [In reply to]	Can't Post

Ron,

Thanks for all your help. While I didn't get the TV fixed, I learned quite a few lessons along the way. Fixing the TV was one objective but just the process of fixing it means more. I'm wanting to learn about circuits and components and how they interact, and I appreciate your helping me with that. Thanks for giving me your valuable time. I will continue to read other post around here, so don't be surprised when I ask a few questions.

You and your family have a wonderful christmas and a Happy New Year.

Thanks again.
Don

dgentry516
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Dec 23, 2010, 1:06 AM

Post #83 of 84 (1055 views)
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Re: [dgentry516] Need Ron M [In reply to]	Can't Post

Ron,

One last thing. Do you think that the problem could be in the board itself? Maybe got too hot and the connections to the board and components are not good? Looking closer around those resistors 613 and 618, it appears to be a darker brown on the board, i.e. darker than the rest of the board.

Thanks
Don

Ron.M
Veteran

Dec 23, 2010, 3:25 AM

Post #84 of 84 (1053 views)
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Re: [dgentry516] Need Ron M [In reply to]	Can't Post

dgentry516;....

Those resistors are 2 watters...
They will normally get a bit warm , not overly hot unless there is a problem with Q601....
So over time the board will get a dark brown....
The important part is the copper foil that is the "wiring" on the board...
If it's still in good shape , then don't worry too much about the color...
If the board is blackened , THEN you got a problem....

If you have nothing better to do , you can get a magnifying glass & look the entire board over for bad solder connections & have fun with that experience....
If you find any , try to repair them by resoldering them....
See what happens....

Have fun.....

Good Luck.....

Later...Ron.M.... Cool

.....
Veteran & Retired TV technician

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