Amiga A1200 RGB & composite video problem solution!

[Anemos]

Amiga A1200 RGB & composite video problem solution!

Anemos back in the lab...

I had an A1200 with severe display problems, flashing - distortion - unstable display, even blanking.

I have no idea why this problem appeared, but I managed to find a solution, that actually gives a much brighter and stable picture with vivid colors.

The solution was to add a small 3mm light-diode in the specific place that is shown in the picture below
(I have also tried several regular diodes with relativelly good results, but none provided the same stabillity and brightness as the light-diode)
I must stress that due to the nature of this problem, my solution might not have the same results as mine, still worths a try!
Make with  your trial responsibility
(thanks to keropi for translate!)

The problem



in the lab



solution



solution - zoom   



Upgrade with a cap




Final screen! .. 

   

[Anemos]

ok,all is Engish now,with one more upgrade cap (look the 5th photo)
thanks to keropi for translate!

[FOL]

Intresting, as an LED is bascially a diode, that emits light.

What type of diodes were you trying?

[Anemos]

@FOL ,2 types Zener Diodes
like this one

[FOL]

@FOL ,2 types Zener Diodes
like this one

Yeh but, you said standard diodes. Zener Diodes are not standard diodes.

What about 1N4001, thats a standard diode, might be well over rated for what we need, but still.

Would really need to look at the circuit to see what it actually does and how it works in the circuit.

[Anemos]

You mean this

I have lot of that diodes,but not test it ,coz is a litle biger size,and the space there is not big.
Any way with this LED and the small cap, working perfect with best stability ,i have close the Amiga and is rdy working 2 days,no more other test...
(if the material working do not touch it any more,is the law)

[FOL]

You mean this

I have lot of that diodes,but not test it ,coz is a litle biger size,and the space there is not big.
Any way with this LED and the small cap, working perfect with best stability ,i have close the Amiga and is rdy working 2 days,no more other test...
(if the material working do not touch it any more,is the law)

lol, you make it fit. Thats what I would do. As an engineer you would come across problems and had to solve em, .

[Anemos]

im not engineer 

[FOL]

im not engineer 

Find the SMD equivelent, or use snipe nose pliers to bend the legs round, so they fit the pads for soldering, .

[Anemos]

i know,but i have rdy finish my pro job there
i play whit this Amiga now.. a little ZOOL 2 .. lol
(Dam me..  i love electronics servise & occupation\...any way , i need other-next damage now for continue my hobby )

[Anemos]

Ok, this is the final FIX, for more stability.
salute.

[FOL]

Can we have a bigger pic of bottom left please. Cant see your markings clearly, .

[Hungry Horace]

Can we have a bigger pic of bottom left please. Cant see your markings clearly, .

you did expand the picture yeah???

looks large enough here!

[Anemos]

direct link>  http://img10.imageshack.us/img10/8262/a1200rgbfinalfix.jpg

Edit: I will stop writing informing to other sites, only for here and in mine forum I will write.
Because somebodies misinterpret the aim of my reports. 

With love,Bebelac creams, more info : http://www.bebelac.com.tr/

[FOL]

With love,Bebelac creams, more info : http://www.bebelac.com.tr/

Are you a spam bot? .