Amiga 4000 Repair Part 2: RAM issues are solved!

In this part, solving the RAM issues once and for all and reassembling this machine. Including converting a 8mb SIMM to a 4mb SIMM!

0:00 Intro
22:10 Converting a 8mb SIMM to a 4MB SIMM

Part 2: This part!

--- Video Links

Amiga Test Kit (RAM Test)

Console5 Cap Kit:

Amiga 1010 External Disk Drive Gotek Mount:

Amiga PCB Explorer:

Amiga 4000 Schematics:

--- Tools

Deoxit D5:

Jonard Tools EX-2 Chip Extractor:

Wiha Chip Lifter:

O-Ring Pick Set: (I use these to lift chips off boards)

Elenco Electronics LP-560 Logic Probe:

Hakko FR301 Desoldering Iron:

Rigol DS1054Z Four Channel Oscilloscope:

Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:

TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)

TS100 Soldering Iron:

EEVBlog 121GW Multimeter:

DSLogic Basic Logic Analyzer:

Magnetic Screw Holder:

Universal ZIP sockets: (clones, used on my ZIF-64 test machine)

RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)

Plato (Clone) Side Cutters: (order five)

Heat Sinks:

Little squeezy bottles: (available elsewhere too)

--- Links

My GitHub repository:

Commodore Computer Club / Vancouver, WA – Portland, OR – PDX Commodore Users Group

--- C64 Stuff

JaffyDOS:

C64 Test Harness I use:

C64 Homebrew cartridge PCB: (used for the DeadTest / Diag Cart I use)

EasyFlash 3 Multi-Cart:

--- Instructional videos

My video on damage-free chip removal:

--- Music

Intro music by:
Nathan Divino
@itsnathandivino

Outro Music:
Attribution 4.0 International (CC BY 4.0)

[SyphistPrime]

Someone finally did it on YouTube. They actually changed a RAM stick's capacity manually. I've been waiting to see this done for a long time. Thank you for showing it can actually be done.

[georgechambers]

The reason for 16 Mb was I used it for graphics work. That's why it had a Toaster and the other cards. I'd like to see some of that stuff running again too. I was never a game player and never used any of my Amigas as game machines. 😁 Thank's for getting it running again it's really good to see!

[FryNOR]

My father taught me that you should count slowly to eleven when turning off electronics before you turn it on again.
Great video, thank you!.

[bearmatic]

Thorougly impressed by your knowledge of chips and their functions, and even more by your persistence, logic deconstruction and fault-finding progress of the RAM issue. Phew!

[thereallantesh]

It amazes me how finicky the RAM issue was. I was super impressed with how you converted the 8 megabyte simms to 4. You should print some custom labels to put on them indicating what they are now. It may help the next guy 25 or 30 years later when he is working on it.

[Mclaneinc]

Superb work as always Adrian, the 4000 is a strangle old beast, my friend used it for MIDI stuff, he decided to get a SCSI drive for it which in those days was horrendously expensive. It arrived, he picked up up and dropped it on to a concrete floor by accident. He was literally in tears....Not only was it dead but it had a mark so he could not send it back as DOA. A lot of money later he was working again and with out a long story showed Jean Michel Jarre the software he used, Bars and Pipes which Jarre had never seen as he was using an ST (I think). True story.. (JMJ was here for the Docklands gig and his friend was the councilor in charge of overseeing the gig, knew Kevin was a fan and brought him around to his house, short version of the story)

[twocvbloke]

Hmm, I never knew that about earlier types of RAM having those solder points to configure them, learning something new every day... :D

[andybasstbn]

My six-year-old son wants to find an old Mac to recap thanks to you!

[NJRoadfan]

A lot of pre-Pentium era machines have compatibility problems with 60ns EDO 72-pin SIMMs. You need to find a good batch of standard 70ns FPM 72-pin SIMMs to have on hand when working with these old machines (386, 486, Macs, Amigas).

[Shifter-ST]

Even I cheered with you when that A4000 finally worked well. And I'm an Atari ST guy. ;-)

[RavenWolfRetroTech]

Adrian, you are testing my resolve to work my way through the computers I had in chronological order. The C=64 is done but I'm not sure I can wait to get a 128 up and running before doing an Amiga. The BEST computer I ever owned! A great video series that is bringing back so many memories!

[BAZFANSHOTHITSClassicTunes]

I had the A1200 from 1993 to 1996. Awesome computer, awesome times.

[barthonhoff]

a rule of thumbs in the 80’s was: Wait 20 seconds before switching the computer back on. Never had any problems

[doug]

Who in the world would ever give Adrian a thumbs down? These videos are awesome and I love every one of them.

[louisnarcisi]

The really strange thing is, I have the exact 4000. With the exact grey slots. That does the same exact things ... As I speak right now, I'm about to go through it again. I've ordered new ram all around. The difference is I had 3.1.4 roms in it. For the hell of it, I've ordered some regular 3.1's like you have, which are here. Plus I have the gotek and the software you have to test the ram. It's all been professionally recapped. Some of the other Amigas, they do not have those exact grey slots. When I install all the ram, both sets even the new set, I get 2 chip, 4 fast. One of the new fast ram chips turns the screen yellow. However, when I do not use that ram, I do not get a yellow screen. Sometimes green flash, but never hangs. You had mentioned the chip ram was 8 I believe? I watched this so many times, I am going by memory now. Mine is actually 2 meg. Curiously, that may be why you are getting the results you are? Because the 2 meg only addresses 1 ... However, when they are all put in the slots. It measures 2 meg chip, 4 meg fast ... I need to think about this more. In case I can't get it. I've ordered a bigramplus card from individual computers. My 4000 is perfect, I hate to waste it. Much doesn't run with just that, 4 fast. 8 as you said is plenty. Also, I need to look at the ram charts. But I received the new ram from someone adept in Amiga stuff. Any input would help, great video!

[Schooner]

Big thumbs up for modding memory! I have never heard of anyone doing that before. Resourceful is an understatement! 👍👏

[wojiaobill]

That Amiga interface looks so slick. Wish I had one of these growing up.

[gremblobeans]

i know this is an old video and i doubt you'll see this but man you do some killer work, keep it up!

[pauledwards]

Thank you for a fabulous video. I feel so grateful and dumb after watching this video. I have boxes and boxes of 72 Simms and spent many an hour going through with a magnifying glass looking at chips to identify them to work out the size of the Simm. Doh, so obvious that they could have a size sense looking back. I even have some with dip switches to change it. Once again thank you.

[sniperviperman]

awesome repair and that nostalgia game: another world at the end makes it the cherry on the cake.