Video and Audio Noise in Amiga 600 Rev 1.5

[Nibbler]

Hi Folks.

I have noticed that my Rev 1.5 Amiga 600 board is very noisy.
This was even before the Recap.

When i turn the audio REALLY LOUD i can hear the humming and buzzing in the Workbench. If i use the mouse it becomes more noticeable. Every move of the mouse creates a Buzz.

The strange thing is that its not only the sound.
Its in the Video too.

When the floppy "clicks" i can see that slightly.
When i use a paint programm like Dpaint, with a grey background and i use the spray can, i can clearly see video noise in the grey.
Especially as long as i keep the mouse button pressed.

I tried also different power supplies. (even a new meanwell)
Best and cleanest result is with the Original PSU from Commodore.

Then i choose to try this with a composite cable and its really bad (Dpaint test)

Well, i use RGB SCart anyway, but still, why the noise in the A600 Rev 1.5 ?

Any ideas guys ?

[Predseda]

How is your audio connected? What do you use as speakers? I have similar problem, if I connect my Amiga to my external amplified speakers together with an output from my external CD-ROM through the audio mixer. If I disconnect the CR-ROM, buzzing is gone.

I am now going to use an audio cable with resistors to hear if it helps.

[Daedalus]

I was going to say that it sounds like capacitors being bad in the PSU, but perhaps there's some problem with grounding somewhere along the line?

[Nibbler]

Originally Posted by Predseda

How is your audio connected? What do you use as speakers? I have similar problem, if I connect my Amiga to my external amplified speakers together with an output from my external CD-ROM through the audio mixer. If I disconnect the CR-ROM, buzzing is gone.

I am now going to use an audio cable with resistors to hear if it helps.

1) I connect via the 2 Cinch straight into this 2.1 Sound system from Logitech. (picture A1) - The Volume would be to loud anyway, but this is still strange

2) In picture A2 you can see those speakers.

3) In A3 you can see the subwoofer.

4) in A4 you can see the Video Noise test. Choose a gray or light gray, cklick on the spaycan and keep the mouse button pressed. You will see Noise. The Camera cant pick up that noise sorry

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The strange thing is that i got my A600 unused and it has been like this since day one. The Recap was done by a "pro" and it did not change anything (besides the weak audio)

Very odd.

I tried different PSU´s. The best is The Original but still.
Now i thinking of getting an Individual VGA Flickerfixer,but who knows if that fixes the slight video issue.

I am running out of ideas

[Amiga1992]

I had this issue on mine when it needed a recap. Noises and screen dimming with floppy access/clicking. But they all went away after a PROPER recap. I first got it recapped by a TV repairman who did a terrible job, and tehse issues remained or got worse, especially the screen dimming on floppy access.

It could be that not all caps were replaced, replaced by wrong value ones, a ground issue, or a PSU issue (did you try another PSU?)

[Nibbler]

Maybe i should consider a recap. By a real pro.
Any Ideas? Who should i ask?

[AwoLStill]

Have you tried connecting it to a different audio output device?
- it could be the monitor / tv that you are using that has the problem!

[Nibbler]

Yup, i also tried it with my LG Flat Tv via scart RGB and the results are not pretty.
Video Noise is visable.

A guy here in austria; from the vienna computer museum told me that you should never use these "kerkos" for a Recap in the Amigas. The Recap was done with this tiny "kerko" thingy's.

I have no idea, but he can fix it, i hope

[Torti-the-Smurf]

I have exactly the same problem.
Tried 3 different A600 Boards and everyone has that video Noise when,
the floppy is loading, the CF Card loading data like crazy,
or any CPU/memory related stuff.
Fact is that the 1.3 Board and two 1.5 Boards had all the same noise problem.
All of them are Recapped and i have 4 powersupply´s. From Original to Meanwell.
BUT, i found this.

[ Show youtube player ]

Get this, he is exchanging the Sony CXA1145M to a Sony CXA2075M.
(in minute 9 of the linked video)
Very interesting and because the newer chip has some of the components inside (like the filtering) THIS is maybe the FIX i was always looking for.

What do you think about that guy´s?.
What are youre experience with the A600 Video output ?

[psoma]

Torti: the CXA2075M mod only affects composite and RF out... if you were still getting noise via. RGB, this (sadly) isn't the fix.

[Torti-the-Smurf]

Aha, so it dosen´t affect the RGB output ? Well, then this end´s my therory right there.
I guess i have to live with it then. Its not relly noticeable in games so i have to live with it.
The strange thing is that i tried so many power supplies and A600 Boards and i have the same result on every combination. Not exactly the same but all have those noise Video problems.
I have send 2 boards to a friend that i really trust but he dosent have those problems at his place.
So, is there maybe something wrong with the power inside my house. (its pretty new but we need alot of Light Bulbs, because the all dont last very long ... very odd.