A1200 display has a green tinge - what's wrong?

[gizmomelb]

Hi all,

my Amiga A1200 (PAL) has recently gotten 'ill' as it now displays a slightly green tinged screen instead of the default workbench 3.x grey.

'green' screen pic 1

'green' screen pic 2

this is the colour it SHOULD be!


I've tried hooking the A1200 to a friend's 1084S, the TV and another friend's 1960 monitor - the same green colour is displayed on all of them so I'm assuming it's definately a video related hardware fault.

Any help or comments as to what the problem might be, or where/what I should be probing with my multimeter would be most appreciated.

Thanks,
Gizmomelb

[dawiper]

If you are lucky it could be just some loose soldering on one/more pins for RGB port.

Other than that I have no idea.

BTW, Have you tried a different cable?

[HellCoder]

How come the mouse pointer is red than ?

[dawiper]

Because blue signal is missing? I don't know

[Ilwrath]

Because blue signal is missing? I don't know

I'd agree.  It looks like blue is weak/missing.

When you hooked it to a TV, did you use the RF out or a SCART cable?  If you used a SCART, try the RF out and see if that looks right.  If it does, you've probably got a loose/bent/broken pin in your 23-pin video port.  If it also looks like blue is missing, it might be a dried up capacitor or poor solder joint somewhere in the video output.  

Either way, I don't think it's anything TOO major, if the machine is otherwise behaving properly.

[tonyvdb]

If you try another cable and that is not the problem You may have to open up the back of the monitor and first try turning the Blue guns colour adjustment. Sometimes these can be reached through some service holes in the back of the monitor without taking the back off. (these are located in an easy location to reach usualy on the back of the guns circuit board) Lables "R" "G" "B" if this makes no difference then it may be that the gun itself is bad or a solder joint has let go on the Blue circuit.
Do adjustments with caution as there are very high voltages inside the monitor and remember where the adjustment pot was before you turned it so you can turn it back if need be.

EDIT: Ok I guess I missed that you did try a 1960 and it did the same thing. If this is the case then I would make sure that your pins on the Amiga video out are straight and none are missing or dammaged. check the circiut conection from the MB to the RGB out and maybe resolder them carefuly.

[HellCoder]

Heeey, be carefull.
I don't think it is the blue component, coz if you're missing blue your workbench should be YELLOW, and not green!!

[balrogsoft]

I had similar problems with my A1200 using RGB output, but my problems was on monitor RGB connector, i got blue and pink colors, the connection had unsoldered from 1084S monitor. Maybe you have the same problem on RGB connector of your Amiga 1200. As dawiper said before.

[Homer]

Umm, was the "colour it should be" picture taken when it was OK, or is there more to this than meets the eye ? Details please  :idea:

[jkirk]

check to see if the video settings in workbench is set for a monochrome monitor. that is freakishly similar tho how did the curser get away.

another possibility tho unlikely is someone is playing a prank and changed your workbench colors.

[gizmomelb]

hi all,

thanks for the comments and help.

some extra info:

I tried at least three different RGB cables (SCART, 9 pin 'D' and 15 pin 'D') but I haven't tried the RF yet.

the 'colour it should be' is my mate's A1200, my machine was working fine before the green appeared (and I checked the WB colour prefs... unfortunately this isn't a practical joke  ).

I'll try the RF tonight, and have a probe around and test the caps and resistors on the RGB this weekend and report back if I have any luck.

Thanks heaps!

[fastrene]

what type of monitor do you have not by the way the 1984s??
on the front site by the monitor (next to sound wheel/switch)is an little switch
this one switch to rgb or green mode try it maybe you pushed it somtime...

[The_Gooze]

Just a thought!

Have you got unshielded speakers next to the monitor as this can cause problems

regards

The_Gooze!

[gizmomelb]

hi guys,

no, no speakers next to the monitor(s).  I tried 2 different models of 1084S, a 1960 and my TV with SCART input.  All of them have the green colour.

[dawiper]

Strange. To get colors like that the green component has to be inc. and the blue has to be reduced. They also has to be adjusted equally. Example: 10% more green and 10% less blue.
I just tried adjusting the pictures in a photoprogram.
I think it has to more than a loose pin/cable.