Amiga hardware info, help and support with a focus (but not limited to) North American NTSC experiences. Open to all.
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obitus1990
New Orleans, LA, USA

by obitus1990 posted Sat Apr 13, 2019 10:58 pm

John Hertell is currently assembling his 3000 board to test it for function. Just finished all the passives, I think , yesterday. He's posting his progress on the Amiga facebook group. I for one want one...my A3000 works perfectly, but, it did have battery leakage that was cleaned up. It will be a pain to transfer all that stuff over if I ever need to, but, at least I have the option!
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RogerWilco486
Boyertown, PA USA

by RogerWilco486 posted Sun Apr 14, 2019 6:21 am

Mr.Toast wrote:Mind if I ping you on some items from the BOM in the future (when I loop back to this project)?


Sure, I've been planning to share my BOM anyway so this gave me a reason to stop dragging my feet. The custom chips and DB-23 sockets came from Individual Computers, just about everything else from DigiKey. I also reused some harder to find parts from my original motherboard--the delay-line IC, 22-degree angled SIMM sockets, self resetting fuse, RTC chip, RTC crystal, RTC trimmer, and the audio jacks.

I had to purchase some NOS 74F841s on eBay because they don't appear to be available new anymore. Those are used for U216.

Below is a link to my Digi-Key BOM in Excel format. In many cases it's cheaper to buy larger quantities of the passive components. That's why you'll see some line items with a much higher quantity than required--because it costs less than buying only the needed amount. I also padded many of these inexpensive passives with spares since it's only a couple cents more and easy to loose these small SMD parts.

Bill of Materials Excel Doc

I should note R179 needs to be subbed with a diode when using a coin cell instead of NiCad--which hopefully everyone does. That's the diode at line item 85 in my BOM.

I hope this helps!
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RogerWilco486
Boyertown, PA USA

by RogerWilco486 posted Sun Jun 23, 2019 6:36 pm

Updated the first post with a picture of the new A3660 installed on this board.
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Mr.Toast
Roseville, CA

by Mr.Toast posted Sun Jun 23, 2019 6:46 pm

Sorry, I've had my head down for the last few months and missed you posting the link to your BOM. That's great. I'd love to get back on to this project-thank you!
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obitus1990
New Orleans, LA, USA

by obitus1990 posted Sun Jun 23, 2019 8:08 pm

Very nice build on the 3660! Where did you get those nice (silicone?) washers you used under the screws to secure it to the motherboard?
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Bulletdust

by Bulletdust posted Mon Jun 24, 2019 1:56 am

The A4000 motherboard's a lot smaller than I thought! Awesome work on the SMD soldering, what do you use for magnification?
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RogerWilco486
Boyertown, PA USA

by RogerWilco486 posted Mon Jun 24, 2019 8:10 am

The spacers are just nylon washers from the hardware store.

As for magnification, since most of the passives are relatively large 1206 size I really didn't need any. It's a pretty easy build, in fact the most difficult aspect of it was fitting the PLCC sockets by hand. I use a Metcal STTC-126 fine bent tip for most SMD work and even with that is was difficult to tack every pin without accidentally melting the plastic sockets. In hindsight I should have brought the board to work and used the IR rework station for those, but I was determined to do it the hard way...
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G8rduc
North Florida

by G8rduc posted Mon Jun 24, 2019 10:47 am

I'm starting to wonder if AmigaKit does ANYTHING well. I ordered a GoTek from them along with some other stuff. Got it all within a week and half. Thought it was great! But the display was having issues. After battling a lack of communications with them, they had me send it to their partner in the States then I had to wait for them to ship it to the UK. Let's say, it's now been over 3 months since this scenario and they're claiming it's about to ship out. Ridiculous company.

Sorry, didn't mean to distract from the OP. BEAUITFUL job on this MB. I wish I had a 1/10th of the skill that some of you guys have on micro work.
Jimmy
Go Gators!
Computers I grew up with: Coleco ADAM, C64, Amiga 1000, Amiga 2000
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RogerWilco486
Boyertown, PA USA

by RogerWilco486 posted Mon Jun 24, 2019 1:08 pm

I should take some pictures of the handiwork done to the original A4000 motherboard...it's _really_ bad. In a few cases all it took was a little pressure to knock the replacement caps right off...cold solders galore. Not to mention the scorched solder mask and lifted pads. There's no denying whoever performed the work was an inexperienced technician.

I will say in their defense, they charge far too little for a quality recap job. Last I checked Amigakit charges less than $50 for the entire job including parts. For them to make any money they're probably paying someone $20/job to crank these out as fast as possible with little regard to quality.

On the other hand, I do electronic repairs on the side and I usually price myself at least $60/hr when producing a statement of work---and I have way too large a backlog to ever be accused of being overpriced.

A simple 4000 recap on my bench would be at least a few hours including fully testing the motherboard both before and after completion.

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