Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 8
Default What causes this kind of failure in a CRT monitor?

Hello, I have a Commodore 15KHz monitor that I tried to use as a TV
set by attaching it to my decoder through a SCART lead. It worked
perfectly for a while, then it started doing this:
http://www.youtube.com/watch?v=GaP2Bv5nCaQ
It hadn't been used for many months or maybe years.
What happened?
  #2   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 8
Default What causes this kind of failure in a CRT monitor?

Jamie t wrote:

That looks like HV leaking somewhere. You may also have some
cracked insulation in the Anode lead or flyback coil. You could
even have a cracked solder joint or moisture in it.


Thank you very much for your advice. It's not doing that anymore. It
looks like some oxide or dirt is present in the vertical size
regulation knob, although I'm not 100% sure.
  #3   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,001
Default What causes this kind of failure in a CRT monitor?

Slater wrote:

Hello, I have a Commodore 15KHz monitor that I tried to use as a TV
set by attaching it to my decoder through a SCART lead. It worked
perfectly for a while, then it started doing this:
http://www.youtube.com/watch?v=GaP2Bv5nCaQ
It hadn't been used for many months or maybe years.
What happened?

take it apart, clean out the dust in it for one thing.

That looks like HV leaking somewhere. You may also have some
cracked insulation in the Anode lead or flyback coil. You could
even have a cracked solder joint or moisture in it.

Jamie



  #4   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 1,001
Default What causes this kind of failure in a CRT monitor?

Slater wrote:

Jamie t wrote:


That looks like HV leaking somewhere. You may also have some
cracked insulation in the Anode lead or flyback coil. You could
even have a cracked solder joint or moisture in it.



Thank you very much for your advice. It's not doing that anymore. It
looks like some oxide or dirt is present in the vertical size
regulation knob, although I'm not 100% sure.

That's another possibility.

Jamie



  #5   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 8
Default What causes this kind of failure in a CRT monitor?

It's doing that thing again. DAMN!!!!


  #6   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 907
Default What causes this kind of failure in a CRT monitor?

Slater wrote:
Jamie t wrote:

That looks like HV leaking somewhere. You may also have some
cracked insulation in the Anode lead or flyback coil. You could
even have a cracked solder joint or moisture in it.


Thank you very much for your advice. It's not doing that anymore. It
looks like some oxide or dirt is present in the vertical size
regulation knob, although I'm not 100% sure.


If the flicker problem changes when you turn the vertical hold or
linearity controls that would indicate a pot problem.

Have you tried control cleaner such as MG's Tuner Lube? About the only
way to restore potentiometers...

Otherwise it could possibly be HV leakage - take the rear cover off and
turn it on in a dark room to see if there is any arcing. You would
likely hear some sizzling noise too and smell ozone if there is a HV leak.

John :-#)#

--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
  #7   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 48
Default What causes this kind of failure in a CRT monitor?


"Slater" wrote in message
...
It's doing that thing again. DAMN!!!!


I know what happened.... You plugged tab A into slot D didn't you.



  #8   Report Post  
Posted to sci.electronics.repair
external usenet poster
 
Posts: 18
Default What causes this kind of failure in a CRT monitor?

Hello, I have a Commodore 15KHz monitor that I tried to use as a TV
set by attaching it to my decoder through a SCART lead. It worked
perfectly for a while, then it started doing this:
http://www.youtube.com/watch?v=GaP2Bv5nCaQ It hadn't been used for
many months or maybe years. What happened?


Slater,
Those monitors, mostly made by NAP (Philips), were notorious for
intermittents of all kinds caused by bad solder joints. When I get one
of those beauties on the bench, the first thing I do is go over the main
(and CRT) board and resolder all suspicious connections, then check for
any other problems, if any. Pay particular attention to the flyback
(LOPT) and H driver transformer, all power transistors, IC's and diodes,
and all resistors of 1 watt and larger... essentially anything that
generates heat. The movement of component leads via heating and cooling
in normal operation eventually causes the solder joints to break loose.
I'll bet your vertical sweep problem is caused by bad solder. Solder
problems can show up when the monitor is cold but go away as it warms
up... or vice-versa.
Be careful when you pull that bottom metal plate off the PC board.
It's soldered all the way around and unless desoldered carefully, you
can damage the grounding traces. Good hunting!

Ray
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
LCD Monitor failure modes ? Adrian Brentnall UK diy 33 February 20th 11 07:54 PM
Pin cushion failure Viewsonic 21 (glass) monitor root Electronics Repair 3 July 6th 09 07:28 AM
Samsung 770TFT monitor failure Al Electronics Repair 3 January 28th 08 04:49 PM
Sony GDM20F03 Monitor Failure Kirk S. Electronics Repair 5 March 29th 05 12:07 AM
Monitor Failure (Sony CPD E220) Thierry Electronics Repair 1 April 18th 04 02:22 PM


All times are GMT +1. The time now is 04:45 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"