I was shocked at what was keeping this Acorn Electron from working (Acorn Electron Repair)

It's time for an exotic (for me) repair of a very interesting 8-bit computer from the makers of the BBC Micro. This Acorn Electric is dead and let's see if we can bring it back to life!

Part 1: This video!

0:00 Intro
0:52 Unboxing
4:33 Background and details on the Acorn Electron
12:24 New modern power supply
18:25 Troubleshooting and repair
46:27 Converting the Electron to NTSC

-- Links

ATX4VC PSU:

Acorn Electron:

BBC Micro:

BBC Literacy Project Archive:

4corn Acord schemtics and service manuals:

PlayUEF: (for loading projects over tape)

Adrian's Digital Basement Merch store:

Adrian's Digital Basement ][ (Second Channel)

Support the channel on Patreon:

-- Tools

Deoxit D5:

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

--- Instructional videos

My video on damage-free chip removal:

--- Music

Intro music and other tracks by:
Nathan Divino
@itsnathandivino

[primate_]

One of the best repair videos you’ve ever put out! Thanks Adrian and thanks to the viewer who sent that awesome little machine in!

[TechnicolorMammoth]

You using the Metal Gear Solid guard alert sound when you discovered the ULA was desoldered made my life. I even showed my wife. I have grown up playing the games and love the Metal Gear series to death, so it really was funny and cool to hear it out of nowhere. I can’t wait for part 2, and you’re a gem, Adrian. I’m so happy to be a patron and support you. Your content has really taken an upswing and it has to be that you can finally full time do what you love, and it shows. Love ya, Adrian, keep it up!

[atomoworkshop]

Fantastic to see the Electron come up! I’m the one who sent it to you and was so excited for when it would pop up.

As for its story like you asked, unfortunately I don’t have much to go off of. I bought second hand as not working and only did quick checks, like you I did a bunch of initial checks and found it not working despite presumably all voltages and such accounted for. However I didn’t turn over the board to find the obvious issue!

Like I said in my letter I did test keyboard on my working machine, so knew it was completely fine luckily. I also did clean it up cause I didn’t wanna send a gross machine though! Hence the tidiness 😅

Anyways I’m glad it worked in end, can’t wait to see more of it.

Quick edit: also a fun fact, in the time since sending the Electron I actually came out as trans and am actually Diana now! 😅

[jamesfcarter]

Great video, Adrian! You can get back your program after hitting BREAK using the OLD command.

[glenrea]

All Acorn 8-bit machines have the ‘Old’ command. Hitting break is a reset and typing OLD or O. will restore the programme.

It’s really useful, as are a lot of BBC Basic’s shorthand commands

[Professorke]

In the mid-1980s to early 1990s, I wrote software for the BBC and designed hardware for a specific group, the physically disabled people. The BBC was the easiest computer to do this on, and in Belgium these old computers are still used in some locations. It is a wonderful machine that has helped many people. I still have a BBC in my house and would not part with it for the world. Due to being idle, several components needed replacing, but it was wonderful to maintain and repair. There is still a whole group of people working on this day in and day out.

[garfstiglz]

My first ever home computer... Brings back so many memories.

[greenaum]

RESTORE is used with READ and DATA. BBC BASIC had a nice little extra keyword called OLD. It's the opposite of NEW! So after a reset you _might_ be able to get your old program back, but do it first thing. Any other messing about you do is likely to scramble the memory pointers and make the old program irrecoverable.

[jameshearne]

You didn't need to replace the original power supply. You can use any laptop DC supply, 15 to 19 Volts DC on the Electron. The switching supply on the power supply board generates the + and -5V supplys without any need to have an AC input.

[MrDodel]

Between the BBC Micro, the Electon and the Archimedes, they all put me on a career in IT, Thanks for the memories Adrian.

[FlyByWireUk]

How cool! I am from London and still have a 40 year old Acorn Electron in a drawer with loads of game tapes and a tape player. I was about 6 when my dad bought it and we spent hours typing in printed magazine listings and running them. That influenced my education path into computer science and then software engineering.

[p_mouse]

Finally seeing someone adding solder while desoldering.
I see so many people just fussing forever to get those pins clean.
A bit of fresh solder does the trick way better!

Great video as always! :)

[tom_]

Jude is very generous and thoughtful. What a wonderful gift and gesture. Very cool, Jude, if you’re reading this.

[gbzy]

I think you're right. The 6502 probably gave up first. Then someone changed it for the wrong version. That lead them to believe the ULA was at fault and started to remove it, damaging a trace in the process, but then gave up and didn't bother to try and re-solder it back. That all makes sense.

[ovislly]

This was my first real computer. My Dad bought it in that year when Acorn were trying to get the Electron ready for the Christmas market, but missed. Plus, it looked on paper almost as good as a Model B yet less expensive. It was an awesome item of kit. I still have it in its original box with all of its original parts and software etc. in my loft. It's built like a brick and still runs perfectly well. I look forward to part 2.

[LittleDancerByGrace]

I think what I like about this channel is that you insist on finding out WHY things don't work or why they were 'fixed' (or not) the way they were. I spent six years working with my dad's contracting company, and my dad was always looking at previous renovations or repairs and trying to figure out why the previous contractor (or owner) would have done things the way they did. (And the more bizarre the 'fix, ' the more entertaining the sleuthing!) I loved that part of working with him, and I've never seen that kind of side-questing anywhere else but here in your videos.

[rockstarpeteuk]

I’m from the U.K. and had one of these around 1984/5. We had the BBC micro in high school, and I begged my parents for one at home. They bought me the Electron and made me go out and get a Saturday job at a butchers to pay them back 😂
I remember sitting for hours on end typing in line after line of basic out of magazines for free programs.
Thanks for bringing back great memories.

[lennymccoy]

Another great video Adrian. Just goes to show how important understanding first principles is ! Manuals contain errors, boards get revised and config isn’t always straightforward. These skills need to be kept alive and sadly all too often in industry i see these skills dying. Your style makes this process both fun and informative which let’s hope inspires more folk to build those analytic skills so needed in engineering.

[mwlge]

My brother and I used to have one that our parents got us for Christmas here in the UK, probably Christmas '83 or '84. Amazingly as soon as you mentioned not being able to LIST the program I said to myself 'OLD, use old'. Truly amazing what the brain has stored away. We upgraded to an Acorn BBC Model B a couple of years later, which we still have and it works, and an Archimedes A440, then A540, the A540 still works as well. Brilliant video, totally enjoyed the restoration. Fantastic !

[smxmm]

About the tape connector: I noticed that the manual mentioned that you can plug it straight into a standard tape recorder if it has the (then) standard DIN audio connector. You mentioned that you saw about 2.5V of audio signal, and in that case the problem might be that it is too loud. IIRC the DIN standard specified a line level of 600 mV.