Acill's Amiga Repair Thread

[wlemonds]

Thanks for getting my board fixed. When anyone needs caps done you need to send your boards to Acill. I've got more boards to send (hopefully not as bad as the last one) soon.

[Acill]

Thanks for getting my board fixed. When anyone needs caps done you need to send your boards to Acill. I've got more boards to send (hopefully not as bad as the last one) soon.

It made it back to you ok? Glad things are all working. It was a challenge!

[Acill]

Some more of Magnetic's 4000. Today I had to remove U177, U975 and U976 so I could clean up under them. U177 is part of the clock circuit and its toast. Luckily it and its other chip above you will see in the last photo can be out of the circuit and the 4000 still functions, just with no clock functionality. You can also see how bad the traces coming off U177 and around it are. They will have to be repaired eventualy if I want to get it working I am sure. My meter isnt working well and I am having a hard time tracing them out to see just how bad they really are.

Chips removed. You can see the real bad traces off to the left from U177


Closer view of the area near U177


U975 and U976 removed. Not quite as bad, but still needed to be replaced with new chips just to be sure.


Cleaned up as best as its going to get and fluxed up for new chips to go down.


New replacements soldered into place


This is the clock chip socket. I removed the chip and well to test the socket for any bad pins and the socket itself. It seemed to be okay.


I still dont have the two 8MB simms in yet to test the simm sockets I replaced. I cant get it to boot because the chip RAM is all I have to use and it runs out of memory and fails to boot from HD. If I boot from a 3.1 floppy it goes to WB and shows only 285,000 free chip RAM. Hope thats correct, but we will see. This is by far the most challenging board I have had in for a long time.

[Acill]

Kirk_M's A1200 caps removed and cleaned up. You can see in the last shots the cap that leaked. Its caused some corrosion but I've cleaned it up and the circuit seems to be fine. This is a perfect example of why you need to recap your Amiga's BEFORE a problem is noticed. These machines are going on over 20+ years. They were never expected to be running as long as we all have been using them.

All cleaned up and ready for recap. First radial is in up near the composite jack.


Close up shots of the leaking cap area before cleanup.






This one will get done once I return from a work trip wednesday next week.

[kirk_m]

Wow, and to think all that was going on with zero glitchiness or symptoms in the computer.  I see you were able to remove the RF modulator Thanks, Paul!

[kneehighspy]

It depends on the job and the component. For surface mount caps I use a hot air desoldering station. For SIMM sockets I prefer to use a handheld desoldering pump but sometimes use a vacuum desoldering station. I also do that for through hole components. Surface chips are all removed with hot air. Through hole all with vacuum desoldering station so it is quick.

I do have a set of Hakko desoldering tweezers, but I dont like to use them. Its to easy to kill a solder pad with those things, so I prefer to just break out the hot air unless its for something fast like one part.



Thanks for the compliment. I am trying hard to save as many as I can and make sure its done right for a fair price!!

thanks for the response!  i have a hakko-fr300 and i like it alot, i just notice your desoldering work looks awesome and wish mine looked like that.  please keep posting your pics, their awesome.  any sites or videos you could point to for some advanced desoldering pointers?

thanks!

//kneehighspy

[kirk_m]

Paul,

I am curious about something.  Why did the text on that chip in the closeup pics disappear on the third  picture?  I am referring to the chip labeled SN75188, at board position U28.

[Acill]

Since I am yet again leaving town for a week on tuesday for a work trip I made sure Kirk_M's 1200 got done. I removed the modulator, replaced the power connector with a NOS one, did a full recap and cleanup. I also reinstalled the indivision AGA MK2 for him. This one is out the door on the 2nd as requested.

[ToddH]

That's some awesome work. Can't wait to see what magic you do with mine.

[Acill]

Just a quick Buster 7 to Buster 11 upgrade in progress here. All cleaned up and ready for the socket to arrive.

[kirk_m]

Just a quick Buster 7 to Buster 11 upgrade in progress here. All cleaned up and ready for the socket to arrive.

WOW.  Please post pics of how the solder paste is laid down prior to affixing the socket.   That's some difficult looking job right there.

[kreciu]

Acill I just noticed. There is sticker: Amiga re-caps by Acill. I do not have sticker, I'm so jealous. I think I need discount next time, due to emotional loses .

[Acill]

Acill I just noticed. There is sticker: Amiga re-caps by Acill. I do not have sticker, I'm so jealous. I think I need discount next time, due to emotional loses .

LOL! Yeah, this is my NEW thing! Next time you get a discount and a free sticker!

[DirtDevil]

Excellent work, Acill.  Been enjoying some dramatic before and after photos!  If you ever decided to make a few videos of some of your efforts, I'm sure they would find a welcome audience.
 
 Thanks for your contribution to the community.

[Acill]

Paul,

I am curious about something.  Why did the text on that chip in the closeup pics disappear on the third  picture?  I am referring to the chip labeled SN75188, at board position U28.

Its just wet still from the IPA cleaning I did in the area is all. Its there once it dried and was cleaned up completely. I was going to remove the chip and replace it, but I noticed I was out of them. After testing the traces and connections to all the legs of it and finding it was solid still I didn't want to risk it.

[Acill]

WOW.  Please post pics of how the solder paste is laid down prior to affixing the socket.   That's some difficult looking job right there.

I am still debating on putting a socket in place or directly soldering the chip on. My preference is direct soldering and not using a socket. The owners usually want a socket, and I have it on order.

If I socket it I usually put a solder pad on two pads opposite one another to tack it in place. Then I run a very fine bead line of paste across every pin on a side in a single line. Yes bridging them all. You drag your iron in a single sweep across them and if done correctly will flow perfectly. Repeat for every side.

Direct solder is tacked first the same way, but I use a wide flat tip. I add the solder to the face of the tip and drag solder along the side. The secret is to brush flux on the pins before you drag solder. It will flow to the pad as you drag across.

I will post some pictures up of course when I get to that point.

Excellent work, Acill.  Been enjoying some dramatic before and after photos!  If you ever decided to make a few videos of some of your efforts, I'm sure they would find a welcome audience.
 
 Thanks for your contribution to the community.

I am thinking of filming the next recap on a clean board I get in. The stuff I am doing right now is nasty work on boards that are very far gone. Its like mad science right now.