Amiga 1200 not working - No CF Booting and No Floppy activity

[MarkJPK]

I had exactly the same issue. There are 3 surface mount caps on the underside of the board that feed the RGB to the composite encoder - I took a guess that either the modulator or the caps were bad and screwing up the signals to the RGB port. Removed the caps and the RGB video output was perfect - obviously disables the composite and modulator but I don't use them anyway.

Depending on your board revision they are either C211, C212 and C213 or C211A, B and C.

[supaduper]

What cable are you using for the Video out ? Composhite or the 23 pin RGB port ? have you tried different video cable ?

[rabidgerry]

Originally Posted by supaduper

What cable are you using for the Video out ? Composhite or the 23 pin RGB port ? have you tried different video cable ?

I use 23pin RGB out into a GBS 8220 up-scaler. I have a custom made cable for this. I've two actually, one rgb to VGA and another to the rgb to 8 pin header on the GBS. Both have same results so I don't think it is that. And besides other Amiga doesn't have the issue.

Originally Posted by MarkJPK

I had exactly the same issue. There are 3 surface mount caps on the underside of the board that feed the RGB to the composite encoder - I took a guess that either the modulator or the caps were bad and screwing up the signals to the RGB port. Removed the caps and the RGB video output was perfect - obviously disables the composite and modulator but I don't use them anyway.

Depending on your board revision they are either C211, C212 and C213 or C211A, B and C.

My board is a rev2b

This sounds interesting. I was thinking of getting rid of the RF modulator anyways, totally don't need it.

I may have to try this then.

If I did this could it be put back to how it was? or is it not going to affect anything other the RF module?

[MarkJPK]

Originally Posted by rabidgerry

My board is a rev2b

This sounds interesting. I was thinking of getting rid of the RF modulator anyways, totally don't need it.

I may have to try this then.

If I did this could it be put back to how it was? or is it not going to affect anything other the RF module?

All you have to do is unmount the 3 caps, this will disable the composite and RF modulator but will hopefully correct the RGB output. To put it back you would have to solder the 3 caps back on.

[rabidgerry]

Suppose it is worth a shot! I shall see if I can do this later.

What revision is your board?

[MarkJPK]

Originally Posted by rabidgerry

Suppose it is worth a shot! I shall see if I can do this later.

What revision is your board?

Mine is a 1D4.

[rabidgerry]

Originally Posted by MarkJPK

Mine is a 1D4.

Ok let me know what you think, but are these the offending caps?



I have outlined C211c in Orange

C211b in Blue
C211a in red (this one is hard to see but do you think this is defo C211a??)

Lemmy know and I will remove them this evening.

[MarkJPK]

Originally Posted by rabidgerry

Ok let me know what you think, but are these the offending caps?



I have outlined C211c in Orange

C211b in Blue
C211a in red (this one is hard to see but do you think this is defo C211a??)

Lemmy know and I will remove them this evening.

From memory I believe they are the same ones I removed. Obviously make sure you are happy too, check the schematic and bell them out if necessary. Interesting that the one in red already looks a bit odd and has some discolouration around it - I recall seeing similar on mine.

[rabidgerry]

So I removed them and I am getting a grey screen with nothing on it now. I shall have to put these back Hope it doesn't matter what way around they go. I know the darker one is C211a but the other two looks the same.

Schematic I can't read them never mind have the one for my board. Too late to try and re-do this all over again I shall put them back on again tomorrow. Thankfully putting back on is easier than getting them off.

[rabidgerry]

The problem is I haven't had a drink yet so I've totally forgot something!

I forgot my fucking Accelerator where the roms are mapped to on my hard drive!

So I fitted the card back in again and rebooted. Well I have a picture!

We shall just have to see what happens now going forward. Will I get the jumpey aboutey colour with purple tint or not?

Plenty of time to test tomorrow. Now where is this guy called Smirnoff been hiding at?

[MarkJPK]

Originally Posted by rabidgerry

The problem is I haven't had a drink yet so I've totally forgot something!

I forgot my fucking Accelerator where the roms are mapped to on my hard drive!

So I fitted the card back in again and rebooted. Well I have a picture!

We shall just have to see what happens now going forward. Will I get the jumpey aboutey colour with purple tint or not?

Plenty of time to test tomorrow. Now where is this guy called Smirnoff been hiding at?

Lol that's a relief, was scratching my head trying to figure out why it would have killed your picture! Be sure to give that area a good clean to get the flux residue off.

[rabidgerry]

Originally Posted by MarkJPK

Lol that's a relief, was scratching my head trying to figure out why it would have killed your picture! Be sure to give that area a good clean to get the flux residue off.

I have to get some pcb cleaner. Been meaning to for a while. So that's all that brownish stuff is then? Flux residue? I think most of that came from the solder wick I was using to lift the solder at the end. I had to use this technique to get the caps off (I don't have a hot air station) [ Show youtube player ]

Yes when the picture was grey I too was also wondering what happened. CF hard drive loaded no problem etc and there was this grey screen. I was tired and forgot my ACA1233n-40 which held the mapped rom. Put it back in and it booted.

So I shall put it through the motions today with a lot of use and see what happens! Certainly it was stable for at least 30 mins after I tried it again last night. Fingers crossed!

[rabidgerry]

Well played some games for about 2 hours. Didn't see any of the jumpey aboutey colours! This could be good!