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  
Old November 14th 03, 06:36 AM
 
Posts: n/a
Default Excessive brightness in Monitor EPSON VGA mono





Monitor EPSON MM-14S, VGA Monochrome. FCC ID: HSUTRLT-1449 (Main Board
TRL-T1448B Rev 4.2)
At the beginning, a change in brightness and contrast from maximum to
minimum, and viceversa, could be observed for periods of 15 minutes.
Finally, after several days, when turning the monitor on, brightness
and contrast were normal. After 2 minutes' time, the brightness reached an
intense maximum, without any possibility of control by means of brightness,
contrast and sub-bright potentiometers.
What should I check first?
P.S.: Might it be possible to obtain the schematic diagram corresponding
to this monitor (or to a monitor with similar features?)?





  #2   Report Post  
Old November 14th 03, 10:07 AM
Jerry G.
 
Posts: n/a
Default Excessive brightness in Monitor EPSON VGA mono

Check for high voltage regulation, main power supply regulation, and bias
volt regulation at the CRT elements. Monitor these points to see where the
change is occurring, and trace back from the out of spec points.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


wrote in message
...




Monitor EPSON MM-14S, VGA Monochrome. FCC ID: HSUTRLT-1449 (Main Board
TRL-T1448B Rev 4.2)
At the beginning, a change in brightness and contrast from maximum to
minimum, and viceversa, could be observed for periods of 15 minutes.
Finally, after several days, when turning the monitor on, brightness
and contrast were normal. After 2 minutes' time, the brightness reached an
intense maximum, without any possibility of control by means of brightness,
contrast and sub-bright potentiometers.
What should I check first?
P.S.: Might it be possible to obtain the schematic diagram corresponding
to this monitor (or to a monitor with similar features?)?





  #3   Report Post  
Old November 16th 03, 01:29 AM
Albert
 
Posts: n/a
Default Excessive brightness in Monitor EPSON VGA mono




Thanks for your prompt reply. I'll try it out.
Albert


On Friday the 14th of November 2003 4.07am, "Jerry G." [email protected]
com wrote:


Check for high voltage regulation, main power supply
regulation, and bias volt regulation at the CRT elements.
Monitor these points to see where the change is occurring,
and trace back from the out of spec points.




wrote in message
...


Monitor EPSON MM-14S, VGA Monochrome. FCC ID: HSUTRLT-1449 (Main Board
TRL-T1448B Rev 4.2)
At the beginning, a change in brightness and contrast from maximum to
minimum, and viceversa, could be observed for periods of 15 minutes.
Finally, after several days, when turning the monitor on, brightness
and contrast were normal. After 2 minutes' time, the brightness reached an
intense maximum, without any possibility of control by means of brightness,
contrast and sub-bright potentiometers.
What should I check first?
P.S.: Might it be possible to obtain the schematic diagram corresponding
to this monitor (or to a monitor with similar features?)?








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
Sony TV stereo / mono fluctuation problems Simon Electronics Repair 4 August 26th 03 06:08 PM
21" Monitor problem: Poor brightness. Dell D1626HT/ Sony GDM-500 chassis Sofie Electronics Repair 2 August 8th 03 05:40 AM


All times are GMT +1. The time now is 01:00 PM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2004-2019 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"

 

Copyright © 2017