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Author Topic: AMIGA 1200 Video problem. Please help!! :)  (Read 2750 times)

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Offline sir_bacharachTopic starter

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AMIGA 1200 Video problem. Please help!! :)
« on: May 29, 2013, 04:41:48 PM »
Hi,
I have just bought Amiga 1200 with the following issues.

When RGB to SCART cable is used the image has a slight red hue.

When Composite is used the image has a strong yellow hue and is torn and moving (not useable).

When RF is used the image is similar to composite but the TV doesnt like the weakness of the image so flicks on and off.

I'm guessing the RGB is the signal at its rawest. So perhaps something between that and the encoder since the composite and RF are both poor.

Another thing is that I have removed the motherboard and found that someone had done some work on the modulator as the solder didn't look perfect. But could a dodgy RF modulator cause the other two outputs to be effected since the modulator is meant to be the last in line to output video?

Are there any caps or resistors you can suggest looking at?

I'm going to test the RGB to Scart cable on a working Amiga to see if the red hue is caused by a component in the cable as the RGB red hue may be coming from that rather than the actual RGB output itself.

I have a multimeter at hand and a soldering iron. I'm ready to go!!

Fingers crossed one or more of this fantastic community can help?
 

Offline sir_bacharachTopic starter

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Re: AMIGA 1200 Video problem. Please help!! :)
« Reply #1 on: May 29, 2013, 07:29:28 PM »
The caps are tiny little square nobbies on these boards arent they? Im used to caps being large cylindri al things. .
 

Offline sir_bacharachTopic starter

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Re: AMIGA 1200 Video problem. Please help!! :)
« Reply #2 on: May 29, 2013, 10:07:05 PM »
Thanks, I think I will take a look at replacing these, I think I'll practice my soldering on some old useless PC parts until I feel confident. :)
 
I'm worried it might be the Video DAC. :S
 
Rob.
 

Offline sir_bacharachTopic starter

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Re: AMIGA 1200 Video problem. Please help!! :)
« Reply #3 on: May 29, 2013, 11:22:25 PM »
Thanks paul. I will give it a go. It's worth a try. I suppose spending thr monrh is worth the experience of frying to fix it. :)

And thanks amiman. The previous work doesnt look to have damaged the mobo. Will see what I can do and will post my findings. :)