EVF CRT wires troubleshooting

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AirRifleSport
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EVF CRT wires troubleshooting

Post by AirRifleSport » 21 Sep 2014, 12:39

Hi guys, I have a CCD-TR303E viewfinder opened up and trying to figure out the wiring. I need some help with identifying one wire labelled:
_____
TALLY What does it mean... What is used for?

On the electronic diagram it shows the word as above, with the line on top of it.
There are 4 wires in total and are labelled as follow:

Pin 1 EVF 5V
Pin 2 EVF GND
Pin 3 EVF OUT (I assume this is the video +ve)
_____
Pin 4 TALLY

Cheers
Franco
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rodp
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Re: EVF CRT wires troubleshooting

Post by rodp » 21 Sep 2014, 12:55

I think that's the one you use for spotting foxes ............ tally Ho :thumbup:


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AirRifleSport
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Re: EVF CRT wires troubleshooting

Post by AirRifleSport » 21 Sep 2014, 12:57

:D
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22-250jock
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Re: EVF CRT wires troubleshooting

Post by 22-250jock » 21 Sep 2014, 13:32

watcha franco

i would guess it may have something to do with on screen menu/battery level etc.....

wouldn't think you need the 4th wire if the other 3 are as you describe,

have you tried it yet to see if you're getting a picture, just using the 3 wires

cheers john
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phoenix
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Re: EVF CRT wires troubleshooting

Post by phoenix » 21 Sep 2014, 15:05

I think the "Tally" wire may produce the recording time display on the CRT.
If so you shouldn't need it.
However, if you were really, really clever, you could maybe hook it up to a rangefinder and get the distance display on the CRT instead of the recording time display.
I haven't got a clue how to do it, but it would be brilliant if it worked!

Cheers

Bruce
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AirRifleSport
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Re: EVF CRT wires troubleshooting

Post by AirRifleSport » 22 Sep 2014, 02:35

:oops: :oops: :oops: disaster :oops: :oops: :oops: :twisted:
I cocked it up guys. After messing about with an old camera I was able to get an image on the viewfinder but 1/3 of the bottom screen was black. Then while trying to switch to different power supply, from battery to mains adaptor and even one of those arduino's power supplier that came with the breadboard, I somehow managed to accidentally feed the viewfinder 12 bloody volts. :twisted: I know, stupid me... :roll:

The viewfinder is now displaying a screen with horizontal black lines when reassembled on the camcorder.

Bruce, the idea of the 4th wire been used to display the LCD readout from a rangefinder is a good one.
The above tells you how really clever I am... :oops: :lol: I leave it to you to show us how it's done.

Time to look for another viewfinder... :roll:

Thanks for replying to the thread guys. :thumbup:
...the doctor said that I need to do gentle exercise... I said to him that I already did... trigger squeezing!

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AirRifleSport
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Re: EVF CRT wires troubleshooting

Post by AirRifleSport » 23 Sep 2014, 21:44

OK...
Can do with some advice. As I blew something on the viewfinder, I decided to investigate for obvious burn marks or blown capacitor (just messing about, as I don't really know what I am doing).

I saw a YouTube video on how to test capacitors, by setting the multimeter on Homs, charging them up and then reading the voltage. I did that on all of the capacitors on the board and found that all of them but one were charging. I removed the odd one from the board and re-tested... not charging!

This is the one:

Image

In your opinion, is it highly likely that this is the only damaged component? As mentioned above, I accidentally fed the viewfinder with 12v and the faulty capacitor is 10v.
Another thing... I managed to lift the copper rings from the two holes where the capacitor was soldered... :oops: they came off from the tracks, I assume this was to do due to a too hot soldering iron? I think I should be able to solder the new capacitor to the tracks, this time using the digital iron, with lower temperature.

The above capacitor seems to be connected in series, positive end to of one to the negative of the next.

Cheers,
Franco
...the doctor said that I need to do gentle exercise... I said to him that I already did... trigger squeezing!

phoenix
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Re: EVF CRT wires troubleshooting

Post by phoenix » 23 Sep 2014, 22:50

If the capacitors ARE connected in series, then 12 volts didn't kill it, because the voltage would have been divided up between them.
It's unusual to have capacitors in a circuit wired in series because, although it doubles their voltage handling capacity it reduces the total capacitance which is what they're there for in the first place.
2 x 10 microfard 20 volt capacitors in series is the same as 1 x 5 microfarad 40 volt capacitor
2 x 10 microfarad 20 volt capacitors in parallel is the same as 1 x 20 microfarad 20 volt capacitor.
If the capacitor is not actually wired in series to another capacitor, then there's a good chance that 12 volts did kill it.

Cheers

Bruce
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AirRifleSport
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Re: EVF CRT wires troubleshooting

Post by AirRifleSport » 23 Sep 2014, 23:49

Bruce, i am not sure about is they are in series. I know it is difficult to figure it out on a thread but here are some more photos of the space where the capacitor was:

Image

Image

Image

Image

I found a service manual for the US market, for model TR303. Mine is the TR303E version but the board seems the same. Page 50 shows a diagram for the VF-42 Board. I tried to make sense of it but might just be Chinese writing to me, :crazy: maybe that is easy for you to understand. :D

There is more diagram info towards on page 50 about the Tally wording, maybe of interest to you? :D

http://www.buyphilipsparts.com/shop/res ... CDTR31.pdf
...the doctor said that I need to do gentle exercise... I said to him that I already did... trigger squeezing!

phoenix
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Re: EVF CRT wires troubleshooting

Post by phoenix » 24 Sep 2014, 07:07

Good find on the manual - it makes figuring outthen wiring a lot easier.
The capacitors are definitely not wired in series.
One end of the capacitor you have removed connnects the the red 2 pin socket and that then connects to the deflection coils in the actual CRT tube.
If you can find another capacitor with the same capacitance, voltage rating and dimensions as the one you removed it could well work
This one should do the job, but compare the dimensions (height, diameter, and leg pitch) before buying http://uk.rs-online.com/web/p/aluminium ... s/0572394/

Cheers

Bruce
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