A1200 Rev 1D.1 - Crackly, Poppy Audio :(

[ElectroBlaster]

I recently found what I believe to be parts of my first ever A1200 from 1995. The board is visually in great shape! All the capacitors have shiny legs/pads. But as with all things of this age and nature I know that means diddly. So last night I got to a point where I could really start to test things:

Hardware:

3.0 Roms
Wizard Power Box 250watt
Converted PC Psu 200watt

ACA1231
Blizzard 1230IV

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So I boot the machine stock with the first game disk I could find which was Road Rage. Turned the Amiga on and noticed weird strange noises! Game loaded with music playing but its terrible all scratchy, really loud and ott. You hear all sorts going on aswell? Buzzing, pops etc.

Then decided to try an ACA1231. When powering up you can hear all these weird noises? they finally settle down and everything appears fine? albeit crackly sound still.

Tried the Blizzard, same thing again!

Tried two different power supplies, same effect!

Then fished out an old 1D.4 board and that one has stable audio. Tried that with the ACA1231 and Blizzard 1230. This time no strange noises at all.

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I am guessing something is amiss here? Both mouse buttons appear to work on the old stall wart tank mouse I used.

If I sent this 1D.1 off to Amigakit, will they be able to fix it?
Is there anything I can do or best leave it be and get it out for repair?

 

[jcarvalho]

Well, I think that Amigakit will exchange the audio caps, and if they are really client concerned, they will replace all mobo caps. If the stratchy noises continues, they will replace the opamp

 

[kipper2k]

i think its the opamp based on a similar iussue i had with an A1200

 

[Deling]

All the capacitors have shiny legs/pads


does not matter , capacitors are dry for 100%
and check -12v

 

[dougal]

Defo the capacitors especially since you say that after a while it settles down.