Classicamiga Forum Retro Edition
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Thread: Harrison's old A4KD has a new home @ Kin's pad
Kin Hell 12:06 19th May 2013
Hiya folks. Chris updated with some more pics recently. His words to me via Email were as follows.

Originally Posted by :

Some more pics of your board, I started working on sound section first.
Pics are of board before any clean and damaged components removed.
I want to get sound working first so, I know there are no major issues.

On side note, daughter board working fine, im still amazed.

Kin Hell 09:12 1st June 2013
Chris updated with some more repair work. Again I include his words to me RE the progress.

Originally Posted by :
Still working on Audio issue. Im hoping to have that sorted by end of today. After replacing Post amp, sound is better but not right.
I have also repaired around 6 pieces of damaged track. The main issue now, is the post amp is missing -12v. So it sounds horrid.
Originally Posted by :
Got sound working right now, from first op amp and it sound really good.
However one issue left with second op amp, one channel seems to be getting carried away. The voltage is incorrect, so the final output is alot louder.
Getting there, . Will send some pics, but please, dont pics as final. As I just tagged stuff on, to see if it worked. Will do a tidy up of board and components once its working perfect.
Originally Posted by :
Not as easy as I had hoped, but getting there. Excuse the mess, as I said in ticket, just interested in getting it working, will do a nice tidy up on it later. I will try my best to make it, so no wire (used to repair track) is shown.
Originally Posted by :
Update on sound problem. I came back to it next day. Only to find the sound was popping.
So I need to hunt for more damaged track, . Ill be happy once I get the sound working perfectly.

DonAmiga 22:49 2nd June 2013
Still a fingers crossed! Which I'm sure will work out fine
Kin Hell 08:58 4th June 2013
Probably, but it's looking like lots of tracks are damaged in the sound circuit and need replacing.
Kin Hell 10:06 5th June 2013
Another update.....

Originally Posted by :
Sorted crackling and popping, now hunting for secong op amp issue.
Could be related to non level -12v rail. Have to I have never seen damage like this, not even on the worst boards I have seen. Its physically eaten into the board itself.

....more carnage.
Harrison 16:37 5th June 2013
Wow. Does he have any idea why there was so much damage? Mad considering it was still working fine. It was always really well cared for too. Always in a dry warm environment, and setup and in regular use all the time I owned it. Very strange.

Does show that all our beloved retro hardware is at that age when it is all going to start breaking down and need some TLC and restoration.
Kin Hell 13:40 6th June 2013
Yeah Dave. Anything this age should have it's Capacitors & any other leakable component replaced with new. I have seen boards far worse than this, 2 of which I acquired from Ireland in a bum deal via Amibench, probably about 10 years ago now. The entire battery side of the board from the Simm slots to the sound area were discoloured with Cap leakage & battery corrosion.

Anyway, it appears Chris has made some serious progress....

Originally Posted by :
Good news, .
I found last issue with sound. It was a pig to find. I had to check each individual component and check each one was going to the correct places.
Tur ns out the feedback resistor wasn\'t connecting the output of 2nd op/amp to input of 2nd op/amp.

Sound is now absolutely perfect, . I will send some pics.

Also I have managed to repair tracks without having unsightly wires showing, . I have tried to keep it as tidy as possible.
I will now move on to the last caps to be replaced. Both are by the clock, which doesn\'t look to good either, the simm sockets for the last simm are corroded quite bad.

Dont worry though, we are almost there, .
I also tested your clock and that holds time perfectly with battery attached. This board just amazes me, lol. I still cant believe it was working to the extent it was, .
I believe the first four pics below are of the repair work to the tracks & components around the OP/AMP section....

Looking good Chris & thanks.

- - - Updated - - -

Didn't expect another update quite so soon....

Originally Posted by :
Yes all caps will be replaced. Still changing them. Just changed he last 47mf caps, 2 just fell off with out effort taking the track with them, .
All sorted though, . The simm socket is perfect. I have cleaned the area where leakage was. All working fine.

Just testing it some more before changing last caps on main board, then I will sort the CPU card.

The above pics are before the repair work is done. Just the offending items removed. - I'll try & liaise with Chris so we have a set of before & after photos in conclusion of this thread.

Looks like the Old Girl is going to survive after all.

FOL 16:53 6th June 2013
Originally Posted by Kin Hell:

I believe the first four pics below are of the repair work to the tracks & components around the OP/AMP section....

You can actually see the fault. 4th pad down on left. Its hard to see unless your looking for it.
The track that connects to the pad is eaten away and makes it look like they were never connected.
Right pain in the **** to find.

On the final stretch now.
Kin Hell 09:17 22nd June 2013
Here are the final pics for now. Just waiting for a glitch on the Shopping cart/checkout routine & then I can pay for the repairs & her journey to her new home in Cornwall.

Chris has had her running for a week on & off to test. Apparently, she is functioning flawlesly.
Harrison 15:24 22nd June 2013
That's brilliant news and great to see the final repaired boards. I don't think I could have sold it to a better person. It is great to know she is fully restored (probably to better than new now) and being cared for and enjoyed.

Was the final repair bill quite high?
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