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j_bogard

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Hello guys. I have an universal chasis WEI-YA429H that works with 9.6 ohms for vertical and 1.3 ohms for horizontal. I found a 29" CRT TV tube that has 7.6 ohms (green/gray) for vertical and 1.5 ohms (red/blue) for horizontal based on my measurements. Could both work? I am not pretty shure about the +/- ohms to work around with chasis and yokes. I still need to buy an isolated AC transformer (120V/120V) to test all the video properly.
 

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I think you can try it without fear of blowing anything up.

If you wanted to be completely sure, you would need to be able to measure impedance (mH).
 
I think you can try it without fear of blowing anything up.

If you wanted to be completely sure, you would need to be able to measure impedance (mH).
You mean "inductance" in millihenrys (mH) :D

Anyway, i think the risk of blowing the chassis is actually related to the impedance (Ohm). A different inductance will lead to bad geometry or not being able to get full screen.

As long as the horizontal impedance is not severely below 1.3 ohms you should be able to try it out. If needed, you can always add a ceramic resistor to get the resistance closer to 1.3ohms.
 
I'm not sure I see the difference in impedance vs inductance. If you're using a regular DMM, you're measuring resistance, not impedance.

EDIT: but yes, you are correct: millihenry is a unit of inductance. Personally, I've found inductance more telling if something will work without issue than just straight resistance.
 
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I tried it last night and had an "emergency shutdown" :P because there was a bit of smoke after a few seconds. So after checking everything the monitor chasis ceramic resistor overheated but without blowing anything :thumbsup: a bit scary but lucky.
I bought an isolation AC transformer for this project (120V to 120V / 100VA) but with the transformer connected nothing happened so after measuring the voltages on it while everything was connected there was about 34 VAC for the outside and not the 120V as it was supose to so then I tried it out without the transformer and there is when the some came out ?(
Either case there was not any tube sound like when it is turning on or sparks while discharging.

1- I will measure the deflection yoke impedance as you said to be more accurate.
2- I will try to check the monitor chasis on a fully functional 29" arcade.

Is there a way to check the CRT picture tube it self besides measuring the deflection yoke? From what I understand damaging it is not that easy but I would like to know how to be sure it is ok since it came in a non functional TV (No. 1A68QCP693X001 PICTURE TUBE 29" - FLAT MSAMSUNG). I did some research but I can't really find what I need.

Is there a well known site to buy monitor arcade chasis besides ebay, amazon and aliexpress? In case arcade chasis is faulty...
 

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You can't use this chassis without an isolation transformer. You've likely blown a diode / diodes on the chassis. Check the ones near the ceramic resistor that started smoking.

As for checking the tube, you need a CRT analyzer / rejuvenator. However, if one is not available to you, assume it's fine.
 
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