Rf modulator A1200

Marc

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Hi all,

I sold Hell_labs my a1200 in this thread here:

https://www.amibay.com/showthread.php?t=8274

Upon receiving he is experiencing problems with the RF modulator which was working before.

These are the symptoms in order of occurance:

1)RF was flickering then turbo card was removed (red/blue were swapping)

2)Turbo card was inserted, turned on while still upside down, it worked! then turned it the right way and suddenly no video. RF nothing, composite just a weird brighter/wavy bit in the middle of the screen

3)Upside down gets composite video, put it right way up and it still worked... RF gets the worlds worst signal (all black with white outlines, rolling, but can just about make out the mouse pointer)

4)I suggested looking at the tuning screw

5)touching the ajusting screw with a screwdriver, then moving away, makes the picture suddenly be perfect black and white, slowly colourise, then the signal goes all crappy again


I am at a loss, I have no idea what might be causing this, but I dont want hell_labs to be unhappy with his purchase either. Anyone here experienced this before or can offer any troubleshooting or advice.

Thanks!
 

rkauer

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Sack the RF modulator out. It is useless, anyway.
 

Zetr0

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Change your power siupply - it sounds like a loud level of interference.

Please be carefull when attempting to operate the A1200 while upsidedown (with an accelerator card) as the adapter card can infact shift and ground out on the EMI protective shield.

At this point I would try another PSU and see where that gets you, although it is wise to mention that the RF unit on the A600/A1200 can and does indeed rot - thus needs replacing.

If you are also experiencing this issue with composite and or RGB then this is a capacitor problem and should be addressed as soon as possible.
 

Marc

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The board is operating fine with composite and with an RGB RF modulator.
 

Hell_Labs

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It's started working again... I dunno what to say... :unsure: Red and blue like to switch places but atleast I can see stuff. I think I'll just get a scart lead.
 

fitzsteve

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It's started working again... I dunno what to say... :unsure: Red and blue like to switch places but atleast I can see stuff. I think I'll just get a scart lead.

Defo get a scart lead you'll get a much better picture full stop. (y)
 

Hell_Labs

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I suppose so, there won't be a bloody ghost haunting the thing any more, atleast thats the best explanation for what was going on. Didn't hear any voices though...
 
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