Welcome to Amiga Love! Tell us a little bit about yourself.
User avatar
Jimbo99

by Jimbo99 posted Sat Jul 28, 2018 12:05 pm

Greeting to fellow Amiga lovers from the woods of northwestern Wisconsin. I'm a retired Ph.D. medical researcher (UCLA, Tufts) trying to simplify my life by unloading things I don't really need. I am the original owner of an Amiga 4000/40 (2M Chip and 4M Fast RAM) and 1084S monitor both very clean, seldom used since about 2007, but well stored. It is equipped with a DPS Personal time-base corrector, an Alfa Data MultifaceCard3 (serial/parallel expansion card), and a Digital Creations SuperGen SX video mixer. It has a Seagate ST3144A hard drive, working well, and a Chinon FZ-357A floppy which evidently doesn't work. Since I have no Amiga floppy disks left with which to test it, I ordered the set of Workbench 3.1 disks from AmigaKit (which they assured me was OK even though my system currently runs Workbench 3.0). Obviously I cannot sell a system with no means of disc input. The system is also missing a 3.5" low profile faceplate, and the green LED for disk activity doesn't work. I found places on the web where I can buy the LED by the thousands, but I've asked AmigaKit if they could furnish one and also the faceplate. No response so far.

Let me digress a minute to tell you what I was using the Amiga for. I had a startup business called SportLabs in the late 1980's for improved teaching of the golf swing. In about 1984 I was getting tired of academic politics at the Univ. of California and decided to try my hand at biomechanics using an Apple II computer and pictures of Jack Nicklaus' golf swing from front and side (down the line). I got a Phase I SBIR Grant for $50,000 from the NIH to get started. I purchased an Apollo workstation, and by digitizing 21 key points on the body from two or more angles using color 16mm film of a number of golf pros, was able using FORTRAN programming to generate 3D models of the "ideal" golf swing. Then using the Amiga 2500 initially, with C programming help from Ron Peterson of Amherst, MA was able to put together a system including Panasonic AG-1960 video tape recorders of the golf students' golf swings, we were able to superimpose subject and model using real 3D perspective from any angle and camera distance. One exceptional feature of our video/computer system was that we were able to stop action on student videos with jitter-free 60 images per second (freeze field), using the additional horizontal resolution of S-VHS. Everything, including the VCRs was controlled from the Amiga keyboard using various keystrokes and a well-labeled keyboard. Three of my systems were in use at the PGA National golf course by teaching pro Mike Adams in Palm Beach Gardens, FL. See Utube video of the system in action: https://www.youtube.com/watch?v=mLZC7hXIpP0. It worked out well for Mike, but financially I lost my shirt, not being well enough funded and not having the time to do both technical and marketing. The collapse of Amiga really put the nail in the coffin. But the whole venture was very interesting, and I learned a lot -- still an avid golfer at 80 years old.

Of course, I've forgotten much about the Amiga since I last used it 15 years ago, spending my time writing books on military history, so bear with me. When I connected the 4000 to the monitor and turned them on, it booted up almost immediately, maybe after a couple tries. I took the system apart and removed the not too messy battery, cleaned it up, and replaced it with the new button battery from AmigaKit. Shortly thereafter the power switch on the monitor failed, and I replaced that with a part also from England. The fully reassembled system worked pretty well for 4 or 5 days. I was stymied why the system couldn't find the battery-backed clock, and began to wonder if the missing dongle (for joystick port, basically 4 resistors whose values I forget) or perhaps our modifications to the Startup-Sequence was making the system unusable. So I started boning back up on AmigaDos, and today I found a version of the golf model software that required no dongle, and was very pleased to be running it again. The program seemed to freeze up. I was not able to quit gracefully, so I turned off the computer. And I have not been able to restart it since.

I get no colored screens of any kind after removing the SIMM cards, both together, or fast RAM only. Maybe it's time for the first recapping of the system? Any suggestions out there? I'd be very happy to receive your suggestions, and also willing to pay for consulting.

Best regards,
Jim
User avatar
intric8
Seattle, WA, USA

by intric8 posted Sat Jul 28, 2018 12:54 pm

Hi Jim! Wow - thank you SO much for joining and sharing that amazing history with us. I read it like I was reading a Tom Clancy novel. Completely impressive and fantastic what you did back in the day.

As for your machine... the 4000 is fairly notorious for its capacitors going bad over the years. Oftentimes folks will pull the entire motherboard out and have all of the "caps" replaced by a professional who's good with soldering. There are a few left here and there that do that sort of thing as a hobby.

But if the caps blow (which happens fairly often with machines that site for many years as they dry out) they can sometimes take other chips with them, unfortunately, and it can become a challenging mystery. It's also entirely possible that you may have had a cap blow in your internal PSU. I'm sorry I don't have better news or suggestions. The 4000, while a crown jewel from a performance standpoint, is known to have these issues as they age. They are fixable if caught ahead of time.

Thanks again for sharing your history there. And it's quite possible someone here might have a better suggestion for you.
User avatar
Bulletdust

by Bulletdust posted Sat Jul 28, 2018 2:21 pm

You can almost guarantee your issue will have something to do with the leaking battery, especially considering your comments re: The clock issue.

A good trick for locating damaged traces (works better with a magnifier, but still possible if your eyesight's better than mine!) is to remove the motherboard and hold it over a light source, letting the light illuminate the PCB from behind. Inspect the traces around the removed battery closely, there will be something there. Also check the legs of the various IC's in the area to ensure correct contact and no corrosion or legs corroded through entirely - I recommend a full reseat of all removable IC's.

Hope this helps!
User avatar
Jimbo99

by Jimbo99 posted Sat Jul 28, 2018 6:30 pm

Thanks very much, intric8, for your warm welcome and helpful suggestions. Thank you, Bulletdust, for your very solid ideas. I will be following up on both your suggestions in the next few days.
Cheers,
Jimbo
User avatar
Jimbo99

by Jimbo99 posted Sat Jul 28, 2018 6:37 pm

To intric8, sorry I had to look up the meaning of PSU. I did check the power supply output with a multimeter and the 5 volts and 12 volts looked OK. If a capacitor were blown in the PSU, would you expect a choppy waveform on one or both? I do have an oscilloscope available for that.
Best, Jim
User avatar
Dynamic_Computing

by Dynamic_Computing posted Sun Jul 29, 2018 8:39 am

I had issues with my A4000 when I took it out of storage a few months back. Black screen and not much else. I took out the A3640 Accelerator card, wiped down the contacts a bit, and reseated it, it came right up. The fun part is that you have to take out the disk drive dray to get to the card. You may try just pushing down on the back of the card to make sure it is making good contact with it's header.
https://www.youtube.com/c/10minuteamigaretrocast
@10marc1 on Twitter
User avatar
Jimbo99

by Jimbo99 posted Sun Jul 29, 2018 5:59 pm

Dear Dynamic,

Your suggestion was fantastic!! I'm back on the air again! The board that I removed, tried to clean contacts a bit and reseated sits piggyback on and parallel to the motherboard, and sits right next to the floppy drives, right? You called it the accelerator card and it is imprinted with the number 3640. Just so we're on the same page, it has a big heat sink sitting directly in contact with the cpu chip, am I right?

Thank you so very much,
Jim
User avatar
intric8
Seattle, WA, USA

by intric8 posted Sun Jul 29, 2018 8:54 pm

Congrats!!!
User avatar
Dynamic_Computing

by Dynamic_Computing posted Mon Jul 30, 2018 6:21 am

So glad I could help! Yep - that is the card!
I am glad your story has a happy ending!
https://www.youtube.com/c/10minuteamigaretrocast
@10marc1 on Twitter
User avatar
Jimbo99

by Jimbo99 posted Mon Jul 30, 2018 11:53 am

Guys,

Thanks for the good wishes, but the plot thickens. After running the system for 15 minutes or so, it has a habit of freezing up and must be shut down. I notice that many of the small ships on the 3640 board run very hot, and some of their labels have melted off, no doubt in use some years ago. This is running without the cover on so their is no cooling from the power supply fan. (I am considering putting a bigger fan in the old power supply, something like the mk3 0060 I read on line somewhere that pulls 30 cpm rather than 20 cpm. Or possibly putting in a new ATX power supply.) Anyone have experience with that?
My a3640 is version 3.0. I understand it is prone to overheating. Version 3.2 is supposed to run much cooler, but I'm not sure how to get one. Then I read about the fact that my capacitors C105, C106, and C107 may be reversed, and I verified that's the case. I'm confident in normal soldering, but not for surface-mount. Maybe I need to get the capacitors changed on the a3640 and the motherboard all at the same time. Any recommendations on who does this kind of work in the USA?
Now I'm digging into the Chinon FZ-357A and trying to see why it's non-functional.

Thanks again for your ideas so far and moral support. Much appreciated,
Jim

Who is online

Users browsing this forum: No registered users and 1 guest