About Phillip Goin Expertise I have been a component-level electronics technician specializing in video sub-systems, cards and monitors for the last 20 yrs. I can resolve bugs, errors, failures, poor colors or resolution and even revive dead units. I owned my own electronics repair business in Philadelphia for 10 years, served as an Aviation Electronics technician in the US Navy for 3 1/2 years, and have been on contract with Northrop Grumman IT`s peripheral repair shop for the past 8 yrs.
Experience Electronics technician to the componant level on video sub-systems, cards and monitors for the last twenty years. Owned my own electronics repair business in Philadelphia for ten years. Aviation Electronics technician in the USN for three and one half years. I spent five years in silicon valley working for referb and retail houses. Currently almost eight years as a technician for Northrop Grumman Information Technologies on USPS contract working in the periferial repair shop.
Education/Credentials AV "A" School USN, EEAS University of Memphis, ASCS UCSD, BSEE UCSD, Sencor Tough Dog school, DEC VAR Alpha school, Compaq VAR, Wyse Certification. Olivette Certification. Sony Authorized service technician.
Question OK, TO CUT A LONG STORY SHORT ....... RECENTLY I ACQUIRED 2 LCD MONITORS AT THE RITE PRICE (FREE). MONITOR 1 , HP 1502 WILL BRIEFLY DISPLAY (THE DISPLAY 'FLICKERS')A SCREEN ON BOOTUP THEN GOES BLANK , THE POWER LED THEN STARTS TO BLINK (GREEN).MONITOR 2 IBM 6734-AC1,SHOWS NO SIGNS OF LIFE AT ALL , I HAVE CHECKED POWER IN , AND THE BOARD IS ACTIVE AT THE MAIN FUSE INPUT , FROM READING OTHER Q&A I'M GUESSING POWER SUPPLY/COIL PROBS . I LIVE IN AUSTRALIA, SO REPLACEMENT IS NOT REALLY AN OPTION (ABOUT DOUBLE US $$) I'M A DIY PERSON , AND A COMPETANT SOLDERER , JUST NEED TO BE POINTED IN THE RIGHT DIRECTION . HOPE YOU CAN HELP, THANX ...... RICK
Answer Ok Rick;
If you have a multimeter, and can use it, I would start at the Diodes near the small rectangular transformer near the main fuse. This transformer is about 2" X 1.5" and about 1.5" high. There should be 3 or 4 diodes. These will be componants with one stripe on them, and a leg out each end. The end with the stripe is the Cathode, or negative end of the diode. Setting the multimeter on Ohms X 1000 scale or Diode check, with the unit un-powered, you can verify conduction, "Low Resistance", with the black lead touching the cathode, and the red lead touching the other lead. Next check for no conduction, "Very High resistance", and this will take a moment to stabelise due to capacitors around the diodes, when you reverse the leads. Any diodes that show conduction in both directions should be un-soldered and tested off of the board. Replace any diodes in question with exact replacements and then look for the Capacitors, "Look like Beer Cans", connected to the end of the diodes not going to the transformer. Replace any that are connected to the failed diodes. Next you will find a Transistor, Three legged device attatched to a piece of aluminum standing off the board near the transformer, replace it with an exact match, and be careful to isolate this device if the original was isolated from the aluminum heat sink. Also use heat sink compound on the new transistor. There may be a feed back chip either a six or eight pin chip that has one side hooked to things on one side of the transformer and the other side to the other side of the transformer. This is an opto-Coupler, and should be replaced also. Since this is an LCD monitor in each case, you do not have a High Voltage circuit to worry about.
