Main Restorations Software Audio/Jukebox/MP3 Everything Else Buy/Sell/Trade
Project Announcements Monitor/Video GroovyMAME Merit/JVL Touchscreen Meet Up Retail Vendors
Driving & Racing Woodworking Software Support Forums Consoles Project Arcade Reviews
Automated Projects Artwork Frontend Support Forums Pinball Forum Discussion Old Boards
Raspberry Pi & Dev Board controls.dat Linux Miscellaneous Arcade Wiki Discussion Old Archives
Lightguns Arcade1Up Try the site in https mode Site News

Unread posts | New Replies | Recent posts | Rules | Chatroom | Wiki | File Repository | RSS | Submit news

  

Author Topic: Bright things cause dark band across screen  (Read 1070 times)

0 Members and 1 Guest are viewing this topic.

crashwg

  • Trade Count: (+10)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 3076
  • Last login:May 24, 2019, 11:01:05 am
Bright things cause dark band across screen
« on: August 22, 2011, 09:40:27 pm »
I've got this TV that might end up in an arcade machine if I can fix this little issue.  The problem is on mostly dark screens where there is bright spots like words or other bright objects.  When there is such a bright thing on the screen it is always accompanied by a band of darkness that is the same height as the bright thing and spans from left to right.  I'm not sure if my description is clear enough so here's a M$ Paint depiction.  What's the fix oh great monitor gurus?
If there's bees in the trap I'm catching em
By the thorax and abdomen
And sanding the stingers down to a rough quill
Then I dip em in ink, and I scribble a bit
But if it they wriggle then I tickle em until they hold still
Lemme say it again
In my land of pretend
I use bees as a mf'n pen

lilshawn

  • Trade Count: (+3)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 7513
  • Last login:Yesterday at 06:49:54 pm
  • I break stuff...then fix it...sometimes
Re: Bright things cause dark band across screen
« Reply #1 on: August 23, 2011, 07:39:32 pm »
you might have an issue with the B+ being a little low....

but more likely you have a capacitor in around the flyback that is getting weak.

the power used to drive the picture from black to white needs to be nice and steady and not vary. if it varies, the you get a weird banding or sometimes in extreme cases you get a screen that starts to collapse in on itself (get smaller) when it gets bright. usually it's a failing capacitor but could be a B+ going all over the place.