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Main => Monitor/Video Forum => Topic started by: kardenm on October 16, 2013, 10:04:25 am

Title: Pentranic 688 wavieness
Post by: kardenm on October 16, 2013, 10:04:25 am

Ok.  Been a while but I'm back to working on monitors.

I have a Pentranic model 688.  Picture has moving wavieness in it.  I have tested or replaced ALL the ELECTROLYTIC caps.  All are very good or new but the wavieness persists!!  I was sure this was a cap problem so now I'm mystified?

Any help would be appreciated.   :dunno

Title: Re: Pentranic 688 wavieness
Post by: Rickn on October 16, 2013, 11:09:23 am

The Ch688 is a chassis that requires isolation transformer. If it has been connected without, then likely a number of diodes and the filter cap in the power supply. Having said that it should have also popped the fuse.

Title: Re: Pentranic 688 wavieness
Post by: kardenm on October 16, 2013, 02:07:26 pm

Thanks Rickn. 

This monitor has always been connected through an isolation transformer.  Other than the wavieness, it works fine.  Good picture, color, etc.

Title: Re: Pentranic 688 wavieness
Post by: kardenm on October 16, 2013, 03:34:53 pm

Now the picture is also "jumping".  Shrinking and expanding slightly in height.

Title: Re: Pentranic 688 wavieness
Post by: kardenm on October 30, 2013, 10:27:40 pm

Ok.  The jumping was simply a bad solder joint but the wavieness is still present.  Any suggestions out there?