Hantarex Polo 25/28 Squealing

[perjmolsen]

Hi

What can cause this?



My monitor is Squealing..

I thought that it just where a bad solder joint on the neck board at the focus wire but it looked fine to me.

[grantspain]

replaced caps?

[perjmolsen]

Hi

No not yet, I have just looked for cold joints.
 I am thinking to start with the polyester caps near the flyback, would that be an idea?

[grantspain]

they are worth checking
you should check the earth pins on the flyback and the earth through screw near the power input

[perjmolsen]

Hi

An update

I have now
- Tested all the volts, they are good.

- re-flowed all the pins at the flyback.. same issue
- Put in new polyester caps .. same issue
- changed flyback to a new one.. same issue

I am thinking it might be a sync issue?
So i have tried to change C149 and C150... same issue
Also tested T110 and T112, they tests OK

Next thing is to replace IC104 with a new TDA2593

[grantspain]

in the video it loses focus for a second, it could be related to crt socket
do you get same issue with no signal applied and raster obtained

[perjmolsen]

Hi Grant 

When I have no signal applied (also test video is OFF at the adjustment board)
I get this on screen when i turn up the screen volts at the flyback


If I turn down screen volts at flyback I still have that strange sound, but no picture of course

Strange what causes that flickering and squealing sound....
I have looked at the pins and socet at the neckcard, they all look fine.

I am still thinking if it can be  IC104??
I have some new ones.. so do you think it is worth trying to put in a socket and a new IC?

[perjmolsen]

Hmm...

Not IC104... I have changed it still the same 

[princess prin prin]

It's one of the new flybacks that are available now. Why did you replace the old one? If you have an original one, try that.

[perjmolsen]

Yes it is a new style one.
I just replaved it to see if it where the cause.
But it did not change anything.

I will put in the old one again.

[perjmolsen]

Put the original flyback back.. still the same issue... 

[grantspain]

looked at the crt socket, looks ok must be ok then