Problems with display and Indivision ECS

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  • Hi,


    I have a Indivision ECS installed in my Amiga 500 plus together with a ACA500plus. It works really great in that setup.


    But when I connect a Blizzard 1260 or a Blizzard 1230-IV too it, I get vertical distortion on the screen. On Workbench and in games. It becomes more distortion on the screen if the computer has been powered on for a while.


    If I connect the Amiga to the RGB-port directly I don't see any glitches at all. And if I unplug the 1260/1230 it works great too through the Indivision.


    I have tried with a different PSU, and also to unplug the Denise chip. Tried different SIMMS, and to disable MAPROM on the 1260/1230 among other things. I even have tried with my older ACA500 card together with the 1260/1230. But it will always display those vertical glitches all along.


    Any idea what can be the problem?


    My card looks like this btw, if that can reveal anything:




    Regards,


    Thomas

  • This does sound like a power supply issue, so at this point, I have to assume that your twp PSUs both have the same weakness. After all, the Amiga with two accelerators and the flicker fixer does draw considerable power.


    a close-up photo of the components under Denise will show me more. There has been a change in assembly of these flickerfixers to make them more immune against power supply ripple. So please remove the Denise chip and post a new photo.

  • Your picture shows that the fix that makes the unit more immune against ripple is already applied (and even a few extra caps that were later removed from that fix-list). This clearly shows that both your PSUs react the same way to a high load: They add ripple pretty badly.


    Do you have a chance to re-cap these PSUs? Are they switch mode (light type) or transformer type (heavy) PSUs?

  • Both are the the switched types. One A1200 version and one A500 version. But good to know what is the problem here.

    I'll see if I can get it recapped. Otherwise I will order a replacement PSU from e.g Lotharek.


    Thanks a lot for the answers!

  • The Indivision ECS is mounted on an Amiga 500 rev8.1a ; I attach a picture. It has a fix applied but looks different from this one. Maybe I could modify it somehow to fix the problem?

    That fix is a different one, so you may have a different issue.


    The original poster here described that the problems change with load on the power supply. Is that the same on your setup?

  • I am unsure it varies with power load. However the problem does vary (some games are barely affected, on others it is very strong).

    It also seems the problem is stronger when the floppy drive runs. It is quite bad on the boot screen, see video:

    https://www.dropbox.com/s/0xmy…_20190127_191607.mp4?dl=0


    I see two different types of issue. The largest ones are random horizontal lines (typically black), as well as speckles for instance below the mouse cursor.


    The second one is barely visible (not really an issue - just mentioning in case it helps), but there is a slight vertical wobble. For instance the ECS Indivision startup screen is clean from defects but shows this slight wobble.


    I tested two different PSUs, one switch and one transformer, the issue remained. (I also rechecked the ECS is properly settled, and I could not push it more).


    Thanks!

  • Can't view the vid - Dropbox won't give me the file unless I tear down all security measures here.


    Anyway, the floppy drive affecting glitches does point to a power related issue, and that's both of them: One can likely be solved by exchanging the ferrite bead with a 10R resistor, and maybe adding another ceramic cap on the PLL's voltage inputs. We can do that here if you don't feel like doing SMD soldering on your flicker fixer.


    The wobble also sounds like a power related issue, but that's most likely a grounding problem. Is there any HiFi equipment connected to the Amiga that has an earth or antenna connection? Maybe an amplifier that has more connections to other devices? I'm looking for a ground loop here that causes this wobble.

  • Thanks - I think I'll try applying the fix. Swapping the ferrite bead sounds doable. To be sure: is it the one just bottom left of the "U14" label? It's been replaced by the resistor already on the image sent by sledge, correct?


    That being said, I am located less than 300 km away, so maybe sending back and forth is not so difficult...


    Regarding the (slight) wobble, the Amiga and screen are indeed in a room close to HiFi equipment ; not on the same plug, but could be on the same power line.

  • Thanks - I think I'll try applying the fix. Swapping the ferrite bead sounds doable. To be sure: is it the one just bottom left of the "U14" label? It's been replaced by the resistor already on the image sent by sledge, correct?


    That being said, I am located less than 300 km away, so maybe sending back and forth is not so difficult...


    Regarding the (slight) wobble, the Amiga and screen are indeed in a room close to HiFi equipment ; not on the same plug, but could be on the same power line.

  • . To be sure: is it the one just bottom left of the "U14" label? It's been replaced by the resistor already on the image sent by sledge, correct?

    Correct. The additional resistor already helps a lot in filtering the input voltage, but you might have to add a 10µF ceramic cap on the PLL's side of the resistor.


    No worries about the voltage drop on the resistor: The PLL is a part that starts working properly at 3.3V, and we're talking about the 5V rail here.