I have an A1200 which I'm trying to rebuild. It currently has a Blizzard 060.

the problem is this. the display keeps flickering, wavering when 020 or 060 is used (much more with 060). or when my cdrom starts spinning or when my floppy clicks, or when reading something from hdd, etc.. how do I fix this?

Last edited by Ancalimon on 15-Oct-2011 at 04:46 AM.

@Ancalimon

sounds like a power problem, I know when I hadnt solved the 5v problem on my PPC that everytime my ls120 drive ran, it rebooted. Either that something is grounding on to the shield if you have still got it on .

Last edited by TheAMIgaOne on 15-Oct-2011 at 04:49 AM.

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@Ancalimon

You most likely have a sheilding fault (bad ground). One or more of your cables could be to blame. Such as Floppy, IDE, Power Supply, or Monitor.

I would try replacing the Floppy and IDE cables first.

Drewlio77

@Ancalimon

Think the problem your describing is this. Annoying horizontal flickering bands on an A1200 especially when using the HD or the floppy drive !!!

If so and you're A1200 is a particular version of the revision 1D.4 motherboard then you'll be glad to know it can easily be fixed...

I know this sounds odd but there were two versions of the 1D.4 made (Commodore quality control at it's best) one that can be fixed and one that can't. The only way to find out is by opening up your A1200 and having a look...

Anyway... if yours is the particular model that matches the photos I have taken then the problem is very easilly fixed by simply soldering a 1uf capacitor across two pads which fixes perfectly the annoying flixer...

The location of this on the motherboard is just below the RF Modulator and to the right at the top of the IDE header...

If your A1200 is Rev 1D.4 and looks like this, then you CAN fix the problem...


If your A1200 is Rev 1D.4 and looks likes this, then sorry but you CAN'T fix it with this method...


Here's where you solder a 1uf capacitor to fix the problem...


Here's how it should look when done... problem solved...


I came across this problem myself earlier this year on an A1200 I bought from eBay, flickering badly especially when using the HD or floppy. I took these photos as I was fixing it just in case anyone else had the same problem...

Thankfully it was easily fixed by the addition of the 1uf capacitor and now works perfectly...

Strange thing is, in all these years I had never seen this problem before on any of my A1200's but it turned out the one I just bought from eBay was slightly different from all my other A1200's and it seems this flicker problem was common on this version...

Last edited by Franko on 15-Oct-2011 at 08:43 AM.

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@Franko

A1200 is a 1D4 and it looks exactly like the first picture. thx ;). But is there a smaller 1uf? I have a laptop cdrom there ;) I hope it doesn't get in the way (I guess the hdd cable would cover the fix)

Last edited by Ancalimon on 15-Oct-2011 at 11:30 PM.
Last edited by Ancalimon on 15-Oct-2011 at 11:29 PM.

@Ancalimon

Use of SMD device is ok if you have tools/skill

Chris

@Ancalimon

If it's the same one as the first picture then this fix will solve that problem...

Like QuikSanz says, you can use an SMD one if you have the soldering skills but if not using a "normal" capacitor is fine, just make sure you cut the legs on it short enough so you don't block the hole for the HD's metal caddy...

The HD caddy & HD in mine still fits in without any problem and best of all there is no more annoying flicker...

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@Franko

I seem to have this problem also with 1 of my 2 A1200's. It also seems to dislike blizzardscsi on my 1230 IV... can it be related ?

Strangely enough it's rev 1d.1 and it also does not have component D215 in place

Last edited by Aminicle on 16-Oct-2011 at 01:00 PM.
Last edited by Aminicle on 16-Oct-2011 at 12:58 PM.

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Impatient as I am, I just dismantled a Powersupply from a x86, found the right component in it and soldered it in place .... fixed in 10 minutes ! Thanks for the fix !

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@Ancalimon

You can use a Tantalum 1uf capacitor inplace of the standard electrolytic caps. They are much smaller and easier to solder than surface mount.

Drewlio77

Last edited by Drewlio77 on 16-Oct-2011 at 01:35 PM.

@Aminicle

Just checked through my pile of A1200's and found a 1D.1 revision board. Yet this one has the component in place...

A1200 Rev 1D.1 with THAT component in place (no flicker problems)


I've never had the flicker problem on this one but that's most likely due to it having component D215 in place. However if yours does not have that component on board then personally I would try soldering the 1uf capacitor in place to see if it fixes the problem...

It's up to yourself but a quick of my 1D.1 board against a 1D.4 board show no difference in that area so I would reckon it is most unlikely you would do any damage to your Amiga and should give it a try. Only you can decide that of course but it may well be worth it if it gets rid of that annoying flicker...

EDIT: Oops too late, I see you've sorted it... nice... seems it depends which factory manufactured the motherboards as to whether they left out that component or not...

So that's two 1D.4 & two 1D.1 revisions floating about out there, like I said CBM quality control at it's best...

Last edited by Franko on 16-Oct-2011 at 01:49 PM.
Last edited by Franko on 16-Oct-2011 at 01:48 PM.

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@Franko

A 1D.1 can't be that different when it has the same problem as a 1D.4 ... right guess it seemed

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@Ancalimon

Do you have 1260.library installed? If so, any instructions not available on 060 (but used in 00, 020, 040 software) will be caught and will cause an OS interrupt while they are handled which may cause mouse flicker (like Windoze!). You can install the CyberPatcher utility to stop this, as it replaces the instructions when the program is loaded.

CyberPatcher seems to be available from here: http://powerup.amigaworld.de/index.php?lang=en&page=13 (First item)

It says it's for PowerUP boards, but since it says it includes 68060.library, i'm sure the CyberPatcher should work for Blizzard 1260 too.

Hope that helps.

Last edited by DBAlex on 16-Oct-2011 at 02:06 PM.
Last edited by DBAlex on 16-Oct-2011 at 02:05 PM.

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@Aminicle

From what I've seen there are only a few minor changes to each revision, nothing more than some extra components added but nothing major between any of them...

Like I say the problem only seem to happen on those boards where they left out component D215, why they did that I have no idea as I have two boards manufactured in Germany with the component and one from the Philippines without it and they were all manufactured in the same year and with a couple of months of each other...

Obviously someone at the factory was skimping on costs and it went unnoticed, probably Mehdi Ali filtering off as much cash as he could before he buggered off with the loot...

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The capicitator mentioned by Franko and used by myself is just fine. The only thing i did was fixating it with hot glue. Here is a picture I just made. Everything fits just fine without touching anything.

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@Aminicle

Here's a faulty A1200 1B mainboard I have.
As far as I remember some cable got ripped off and a small chip was burned due to a very old faulty keyboard adapter (was from Ateo in an Ateo tower). it was about a reset cable coming out of the keyboard adapter.




I have this component on a this dead A1200 motherboard. Is it possible to take it out and solder it on the 1d4 one?

I wonder what is the difference between that chip on D215 and a 1uf capacitor on the D215A

@DBAlex: I think I have it. I'll check it later and also post some photos of the inside of the 1d4 A1200. I'm sure there'll be some valuable advice. :)

Last edited by Ancalimon on 16-Oct-2011 at 11:59 PM.
Last edited by Ancalimon on 16-Oct-2011 at 11:57 PM.
Last edited by Ancalimon on 16-Oct-2011 at 11:51 PM.
Last edited by Ancalimon on 16-Oct-2011 at 11:50 PM.

@Ancalimon

If I was you I would just do the fix instead of going through the hassle of desoldering en resoldering that component with the risk it overheats or is already broken.

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