The last 2 days have been technically a fantastic year.  It started with 2 Harris Butt Sets and ended with a fixed Vizio 47" TV.  I had recently failed a cap replacement on an  Insteon device, so my electronics repair road was on a bad path.  It felt good to relive my roots.

 

The TV a Vizio SV470XVT1A was an interesting one, it intermittently displayed video, the back lights always worked.  Lots of documented voltages finally lead to a voltage regulator U10 on the daughter board, 0101-4072-0044 which showed a pin hanging at .4 mv when the set failed, and came up to 1.1 mv when it worked.  What a deal, the daughter board is near the cheapest one in the unit.  Amazon had a seller with a used one for $8.

 

The other items on the table were 2 Harris TS22 Butt sets. One an older model the other an ALO version. They have the quite normal CR2032 button cell went dead issue.   A good number of years ago I'd modified the ALO version with a much larger battery intended for a computer CMOS.

 

 

 

At Christmas, an Uncle of mine, who when I was a child gave me a series of electronics training books tossed a TS22 my way, saying do to mine what you did to yours. Given I still rely on the base knowledge learned from both the electrical and electronics books, I was happy to oblige. One book was named Antennas And Radio Propagation, where the discussion went as far to make antennas using telephone poles to hold the elements, now that's a big antenna. That was a fun book, there's a link at the end.

 

 

 

Back onto the Harris TS22 battery hack

 

The original replacement is still hooked up and working, the voltage was down to 1.4v, so it was close.

The ground wire was cut a bit long in order to solder it to the bottom of the button cell holder.

 

 

The positive pin also has a short lead attached to be used as a bridge for the solder tab holes.  The older model only pulled power from one of the pins, this one uses both. The coin cell holder needed trimmed down to clear the resistor.

 

 

 

 

 

Soldered that down with a squirt of hot glue to help stabilize it transformed the tool from an annoying battery replacement to a simple task.

 

I bought a 5 pack of the coin cell holders at Amazon for 4 bucks. http://amzn.to/1Oyi3aM

 

 

 

 

 

The other unit is a bit prettier as less material was removed from the battery holder.

 

 

 

 

Test Voltages from Vizio
SV470XVT1A

 

Main board

U5 - 2.1v / 3.41v / 4.95v

U45 11.72v/ .6 mv / 5.05v

U16 11.71v / .7 mv / 5.03v

U17  5.06v / 3.38v 2.10v

U19 4.97v / 2.57v / 1.29v

U20 3.38v / 1.84v /.569v

U22 5.14v / 3.39v 2.11v

Q9 0v / 4.97v / 0 v

 

 

20 pin header top left side no cable plugged into it.

1 - 3.39v

2 -

3 - 3.39v

4 - 3.39v

5 - 3.39v

6 - 41mv

7 - 3.39v

8 - 3.87v

9 - 0.9mv

10 - 0.9mv

11 - 3.37mv

12 - 0.9mv

13 - 0.9mv

14 - 0.9mv

15 - 0.9mv

16 - 0.9mv

17 - 0

18 - 0.9mv

19 - 0.9mv

20 - 0.9mv

 

 

Daughter board (Video Processing)

 

U2 - 5.03v / 3.38v / 2.11v

U6 - 3.37v / 1.84v / .57v

U10 - 1.1mv / 1.29v / 3.42v

U12 - 2.12v / 3.41v / 5.03v

Q4 - 3.32v / 3.24v / 11.65v

Q3 -  3.32v / 3.37v / 11.65v

 

 

W2 Power cable entering Video Processing board

1 - 3.38v

2 - 3.37v

3 - 3.37v

4 - low floating  mv range

5 - 3.39v

6 - 3.38 v - Green wire

7 - 3.38v

8 - 0 v

9 - 1 mv

10 - 5.03v white maybe with with black stripe

11 - 5.03v

12 - 3.38v

13 - 3.39v

14 - No wire

End Video Processing Board

 

Power Supply

Starting at the top side with respect to the power cord being down.

 

13 pin molex type plug

 

1 to 5 - 24 v

6 - 21 mv
7-  21mv

8 - 21  mv

9 - 22mv

10 - 22mv

11 - 3.14v

12 - 5.00v

13 - No wire

 

Next connector

1 to 5 - 24 V

6 - 28mv

7 - 28mv

8 - 29mv

10 to 12  - no wire

 

4 Pin connector

1 - 24v

2 - 24v

3 - 21 mv (ground)

4 - 21mv

 

15 Pin connector

1 - 3.3v

2 - 11.76v

3 - 11.76v

4 - 11.76v

5 - 22mv

6 -  22mv

7 - 25mv

8 - -26mv

9 - -26 mv

10 - 5.18v

11 - 5.18v

12 - 5.18v

13 - 3.41v

14 - 4.97v

15 no wire

Ends Power Supply Connectors

 

Link to the book Antennas and Radio Propagation book

http://www.pestingers.net/PDFs/Other_radios/Military_manuals/TM%2011-666%209%20Feb%2053%20NJ7P%20AS.pdf