Ultimate Amiga

Other => Amiga Hardware => Topic started by: Anemos on March 03, 2009, 08:07:46 PM

Title: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 03, 2009, 08:07:46 PM
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

(http://pspemulation2.condor.serverpro3.com/screenshots/@ A1200 video problem-1084.jpg)

in the lab

(http://pspemulation2.condor.serverpro3.com/screenshots/@ergastiri.jpg)

solution

(http://pspemulation2.condor.serverpro3.com/screenshots/@solution-1.jpg)

solution - zoom   

(http://pspemulation2.condor.serverpro3.com/screenshots/@solution-2.jpg)

Upgrade with a cap

(http://pspemulation2.condor.serverpro3.com/screenshots/@upgrade-cap.jpg)


Final screen! ..  ;D

(http://pspemulation2.condor.serverpro3.com/screenshots/@ A1200 video fix-1084.jpg)    
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 05, 2009, 11:48:12 AM
ok,all is Engish now,with one more upgrade cap (look the 5th photo)
thanks to keropi for translate!
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: FOL on March 05, 2009, 10:44:55 PM
Intresting, as an LED is bascially a diode, that emits light.

What type of diodes were you trying?
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 06, 2009, 12:06:00 AM
@FOL ,2 types Zener Diodes
like this one

(http://www.reuk.co.uk/OtherImages/glass-zener-diodes.jpg)
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: FOL on March 06, 2009, 10:36:48 AM
@FOL ,2 types Zener Diodes
like this one

(http://www.reuk.co.uk/OtherImages/glass-zener-diodes.jpg)

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.
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 06, 2009, 12:32:30 PM
You mean this
(http://tbn2.google.com/images?q=tbn:4P6218_L5ox-bM::http://www.cartft.com/image_db/1n4001.jpg)
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... ;D
(if the material working do not touch it any more,is the law)
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: FOL on March 06, 2009, 09:51:52 PM
You mean this
(http://tbn2.google.com/images?q=tbn:4P6218_L5ox-bM::http://www.cartft.com/image_db/1n4001.jpg)
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... ;D
(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, :).
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 07, 2009, 07:01:10 AM
im not engineer  ;D
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: FOL on March 07, 2009, 02:49:03 PM
im not engineer  ;D

Find the SMD equivelent, or use snipe nose pliers to bend the legs round, so they fit the pads for soldering, ;).
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 07, 2009, 03:02:52 PM
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 ) :D
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 10, 2009, 10:52:27 PM
Ok, this is the final FIX, for more stability.
salute.
(http://img10.imageshack.us/img10/8262/a1200rgbfinalfix.jpg)
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: FOL on March 11, 2009, 09:24:42 PM
Can we have a bigger pic of bottom left please. Cant see your markings clearly, :(.
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Hungry Horace on March 11, 2009, 10:25:03 PM
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!
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 11, 2009, 10:29:55 PM
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/
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: FOL on March 14, 2009, 09:20:40 AM

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


Are you a spam bot? ;).
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Hungry Horace on March 14, 2009, 09:38:22 AM

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


Are you a spam bot? ;).

Anemos' sig made me think that too!

Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: Anemos on March 14, 2009, 02:08:47 PM
lol ,no im joking with this link ..  :D
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: DominickMcguire on August 10, 2013, 12:04:38 PM
Intresting, as led lights (http://www.niceledlights.com) bascially a diode, that emits light.

What type of diodes were you trying?


Apart from LED which other lights can we try?
Title: Re: Amiga A1200 RGB & composite video problem solution!
Post by: FOL on August 13, 2013, 11:53:18 PM
Intresting, as led lights (http://www.niceledlights.com) bascially a diode, that emits light.

What type of diodes were you trying?


Apart from LED which other lights can we try?

I wouldn't try any. A normal diode should do.
However, I think Anemos had a fault. This got around the problem.