Higher Capacitor Value For Safety Capacitor
If you come across HOT that always burnt after replacement then you should check out the capacitance value of the safety capacitor which is located nearby the flyback and the HOT. If you do not know which one then try to trace from the collector pin (center pin) of HOT and you should see that a non polar cap that have a high working voltage (from 1600v to 2000v).
Assuming you found that this capacitor value had out or no capacitance at all when test with a digital capacitance meter then i suggest that youfind the exact replacement. Now the problem is the capacitor value is not commonly found found from local electronic supplier. Since this capacitor value is critical you need an exact replacement of it. A too high or too low the capacitance value will have effect on the picture.
After done some research many years ago i found that any CRT Monitor that have this cap problem can actually take in a higher capacitance value with same or higher working voltage. Lets say you found the value of the cap was 5.1nf 1600v you can actually put in a 5.6 nf 1600 v or 2000v (2kv). The slighlty higher value will cause the display to become slightly bigger horizontally but acceptable because you can reduce the width from the front panel control button. If you put a too low capacitance value the Monitor will go into shutdown mode and may also kill the HOT. That means better to replace a slighlty higher value than to replace a lower value.
So, whenever you come across a shorted HOT please check this capacitor value and corresponding components before you install a new HOT and turn the Monitor On again.
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Waleed
May 26, 2009 at 4:16 pm
very good tip. I have came across something like that before and the only way to find another capacitor from another computer monitor that is the same capcitor or any pc that might have this capacitor. sometimes i buy monitors or tv sets that too expensive to repair or can not be repaired and take the pc out and keep it in a special box so i could use these parts even used and hard to find parts. worked fine with me. again, thanks for the valuable tip.
admin
May 26, 2009 at 9:05 pm
HI Waleed,
That's why sometimes i did not throw away those junk boards because i could salvage the parts.
Jestine
ivan
June 25, 2009 at 1:39 pm
please send the messege in mail id sir
admin
June 25, 2009 at 7:12 pm
Hi Ivan,
May i know what message?
Jestine
sathik ali
July 28, 2009 at 7:30 am
I Found this information very Use full.Thank you very much sir.I have a monitor with a problem horizontal width less than normal.I suspect the reason is that picture tube along the yoke is replaced befor by another technician.Now can i increase the width by safly increasing the value of above capacitor.already because of this problem HOT getting little more hot.Im afraid about high frequency Horizontal out put section of MOnitor.Please Clarify my doubt.
admin
July 28, 2009 at 10:26 pm
HI Sathik,
If the tube had been replaced by another technician then changing the cap value will make the HOT get hotter. The best is to get back the original tube spec which i presume it would be very hard to find one.
Jestine
sathik ali
August 7, 2009 at 1:32 pm
Thank you sir For your valuable advice.
admin
August 8, 2009 at 12:20 pm
Hi Sathik,
You are welcome!
Jestine
Jim
December 11, 2009 at 10:28 am
can v replace 1.6k with 2k? will it create any effect in the picture?
admin
December 11, 2009 at 4:02 pm
HI Jim,
Yes you can put in a higher voltage and there will be no effect on the picture.However, the capacitance value has to be the same.
Jestine