mikemaiertv
Enthusiast
Aug 12, 2005, 10:30 PM
Post #6 of 6
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I wrote this about a year ago will repost it , now just rember I'm talking about the 169 chassis not the 195
This will be my general “caned answer” for the CTC 169 or in these cases the PTK169 chassis, first of all the “light box” can be removed from the set making it much easer to work on, first remove the back and on top of the box there is a plug where the front panel attaches to, remove that plug unwrapping it from all the holders on top there may also be a place where the speakers plug in up there but in most cases they snake down and plug in to a board right in the audio output board in the back. Then remove all the screws on the bottom back that hold the chassis in, slowly pull the chassis out making sure the wires don’t snag up and break something.
Once the box is out the set gets real easy to work on, you can use the remote control to turn the set on because the IR sender is located right in front of the green CRT.
Then as general rule we change three capacitors in the power supply no matter way the set failed. These caps tend to dry out driving the B+ voltage high, they are located in front of the plug on the right side of the main board and two are located just left of Ic U4401 cap C4104 or as shown on the board as C104 this will be a 15uf at 50 volts change it to a 22uf , 50 volts and then C102 a 2.2 uf at 100 volts finally the big one to the right of the first two C108 a 39uf at 100 we change this to a 100uf ,100volts. In Every 169 we worked on The B+ voltage is always been high because of these caps wearing out, just by changing these three B+ usually returns to normal.
Then the next most common fail is the high voltage splitter this is located by opening the front of the set where the convergence board is or what was right behind the speaker grill if the chassis is in the set. The splitter is located either on the right side ( From the front ) or in-between the CRT’s it has Four large red wires and one Black wire and may or may not have a small circuit board mounted on it. To test if this is bad find the one red wire that leads back to the fly back (High voltage transformer) and remove it. First of all if this is burned the splitter is bad, next isolate it by either stuffing a paper towel tube over it or getting it at least a good couple of inches away from anything else is the chassis. Then the fun part, rember how you could here the set turn on then off, with this wire removed the set should run, use the remote and start the set staying AWAY from this lead, there will be no light coming from the CRT’s but you should be able to here the set running and not shut down, there are no relays or things that make a click when this set runs and since there are no speaker hooked up either there will be no audio. But the difference between running and not running are fairly obvious. If the set runs then the splitter is bad
Now its part number is 205064 and should cost you about $55.00. A little note on these splitters, several companies have jumped on the band wagon building splitters Always go for the original factory part for this, other even though they have the same number and cost as low as 19.95 will cause you nothing but grief. This part is too critical to go cheap on, because if you do you will be doing this again within a year Guaranteed.
Now if you splitter has the little circuit board attached transfer it to the new splitter and solder the wires, even though the old one only had them wire wrapped solder is a better connection. You may have a sticker stuck to the chassis showing you where all the wires and the length you need to cut the wires to for the splitter. And when you removed the old wire there may have been little rubber band thingys on the end, we have always tossed these because they could bind up inside the tube and messing up the connection. On these tubes you notice there are two stopping point for the plastic holders, what you can do here is put the holder in place to the first stop, insert the wire, making sure every thing enters the splitter perfectly strait, when you feel some resistance stop and push both the wire and the holder to the second stop. You should then see that if you did not have to cut off a burnt end, that the little blue line or wire tie that was on the leads is just above the plastic holder. If all goes well now you can start the set up as before and this time the CRT’s will light
Mike Owens Owner Competition TV Spokane WA.
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