A Couple Of Ideas ...
A Couple Of Ideas ...
Hopefully one of these ideas will solve the problem...
I have a 4460D & vaguely remembered having trouble with a color. I looked in the manual & had left myself a note telling me that a solder joint in the convergence circuit cracked (from heat/cool cycles)- Red was dead. (Details below)
Before Reaching Into The Monitor's Guts:
The bottom of this reply has How-To-Open-The-Case notes.
Be sure the unit is unplugged & the high mfd capacitor is drained. I don't know the 'official' proper way to do this, but an internet search will certainly provide safe details. These can hold charges for months & months. Please be very careful. Usually, the high voltage areas are well marked, but the power, of course, can manifest itself anywhere in the unit. It is also a good idea to wear a grounded wrist strap to dump your own static before it blasts a component in the monitor.
I don't remember where to tell you to look for the convergence circuitry. I think it is usually the board on the back of the CRT. (I learned something new today, so something old fell out. Must have been that.) I'm by no means an electronic repair person, but I've had cracked joints on many circuit boards (mostly entertainment lighting dimmer packs). With an opti-visor or just a good magnifying glass, they are easy to spot. Also look for 'cold' solder joints. They will be dull grey in color. They may conduct fine for years & then quit.
Simple Fixes To Try First:
Sometimes degaussing the CRT can clear up the craziest of problems. I don't see a degauss button on this monitor. A good way to degauss is 1) make sure the unit is plugged into a grounded receptacle if it is 3 prong. If 2 prong, make sure the receptacle is properly polarized (The wide blade goes into the receptacle's neutral. Lots of houses are wired backwards.) These two items will help let the residual (stray) magnetism bleed to earth. 2) Check cleanliness. A TV guy once told me that he sometimes simply cleans greasy dust from cigarette tar or nightclub fog juice off the tube inside to make a variety of problems go away. It can't conduct electricity to dump the built up charge properly. 3) See that the cage, if there is one, is still properly hooked up. It is generally some wires across the back of the CRT. They go to the chassis. If it gets unhooked, there is no way to bleed off the stray current & magnetism.
The cable could be bad or have a bent pin. On yours, if it is the same as my 4460D, Pin 3 is Red & Pin 2 is 2nd Red. If you hold the female end with the wide side up & the holes facing you, pin one is top row, left. It moves right (Pin 5 is last on the top row). The bottom row is pin 6 on the left through pin 9- far right.
You could use a continuity meter from the board the cable terminates on to each pin. (After discharging the capacitor I mentioned above.) But, the male pins on the video card are most easily damaged. Also, there could be dirt or corrosion in the female end. A blast of contact cleaner will clear that out fast.
Last Idea: Did you check the Input Signal/Test Switch? It is the one in front of the power button. Position 1 is RGB 16 or 64 colors. Position 2 is Green Only 3 = Amber Only & 4 = Blue Only. But on mine, if I hit just the right position, I will get everything but blue. So maybe on yours, there is a position where everything but red comes on. Guess it has to do with the video card? I'm not trying to be rude, but if you don't know what this poorly marked switch is for, it is easily overlooked.
The idea you don't want to hear- The red gun is dead. I understand this is unusual, so hopefully it is not the problem.
I hope at least one of these fixes your problem. If not, I've found good information at this web site about all kinds of electronic problems-
http://www.eserviceinfo.com/news.php
There is a forum in there with really helpful professionals. (I'll be hitting it tonight. My 6x86's power supply went dead. I can't figure out which component cooked.)
Opening The 4460D Case: (From my napkin notes shoved in the manual)
Remove Back Case- Push in 4 clips. there is one near each corner. Need small spudge or screwdriver
Remove Front- Pry out 2 plastic pions located on the bottom near the front panel. Separate with a wide, flat blade. Unplug the LED
Remove Top- Remove 2 screws at the top, front corners of the screen. Top lifts off.
Again, I hope at least one of these fixes your situation. And, I hope it is one of the easy & free solutions!
Paul
