Amiga 500 display problems

[shooey]

Hi,

I have an Amiga 500 which I haven't used in a long time, and have been trying to get it working. It boots up fine, but the problem is, I can hardly see the display.

I've tried connecting the RF output into an aeriel socket and tuning in on analogue, and I've tried the video output into a scart socket (capable of RGB) using a fully wired scart adapter, and I've tried the video output into the yellow socket of 3 phono plug connection. I've actually tried all those things on 2 different TV's.

In all cases the picture looked like it wasn't tuned in properly, and on one of the TV's it was rolling.

I've seen in other posts, that rolling can be a sign of NTSC, but I can think of no reason why it would be NTSC as it's an English Amiga and I'd never fiddled about with the settings that I can remember.

Can anyone suggest anything that I can try, or is it likely that the TV modulator no longer works properly?

*apologies for all the incorrect terminology used above, but you can hopefully figure out what I mean*

Thanks

[shooey]

You need to clarify what you mean when you say you used RF.  Amiga 500s do NOT have an RF output as default.  You only get that when you have an A520 connected to the RGB port.

Is that what you meant?

Sorry - when I said 'TV modulator' I meant A520 - I didn't know that's what they were called.

So yes, I have an A520 connected, and have tried the RF and video outputs of the A520.

Anyway, thanks for both replies. GadgetUK suggested a few things to try, so I will do that, and also post some pictures so you can see what the fuzziness looks like.

Thanks

[shooey]

Hi,

I did have an memory expansion in under the one of the flaps underneath and have tried removing that, but it's made no difference. Here are a few pictures...

Thanks

[shooey]

So, did you try the monochrome video output on the actual A500 itself into the video input of your monitor/TV?

It's the little, lone RCA jack beside the RGB video port.

If that works then your A520 may be faulty.

Hi,

No - haven't tried that. Didn't even know you could - I thought 'mono' was referring to audio! Will give that a go...

Thanks

[shooey]

Hi,

Absolutely perfect picture via mono socket. So I guess my A520 is faulty. Thanks very much for all the help.

Cheers

[shooey]

Thanks Gadget. Will have a think what to do, but may get back to you on that...

[shooey]

Thanks. Will give it a go. Nothing to lose...

[shooey]

There are a couple of potentiometers inside the A520 that may just be dirty.  Mark their positions and try twisting them back and forth (with a small screwdriver) then return them to their original positions.  If you have any contact cleaner spray it inside the potentiometers.

It might be that's all that is wrong with the A520.

You can probably find out what these potentiometers do on the internet somewhere.

Hi ral-clan,

Wonder if you'd be kind enough to expand on your what you'd said above?
If we look at the photo here:
http://amiga.resource.cx/photos/a520,4
Which bits are we talking about? Within the metal square on the right hand side, the white thing in the middle looks like it has a screwdriver type hole in it. Or is it the two things either side of that?

Thanks