Broken 1992 AMSTRAD Notepad COMPUTER NC100 - Trying to FIX
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- Опубліковано 30 вер 2021
- Here we have a Amstrad NC100 with no power. This was purchased faulty from eBay. Can it be fixed?
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Remember that this is just for entertainment and I am not an expert in these repairs. The processes in the video may not be the best way, the correct way or the safest way to fix these things. I do love fault finding and trying to fix broken things, so I hope that comes across in this 'Trying to FIX' series. Many thanks, Vince. - Навчання та стиль
Ahhh I'm so excited to watch this.. I remember these, when I was little I wanted one so badly. It blew my mind you could have a PORTABLE computer. I think I started saving my pocket money, and no doubt badgered my Mum to buy one from her Catalogue so I could pay her back weekly. Thank you Vince for stirring my memories.
Awww, cheap compared to the other laptops at the time but unfortunately probably still a years worth of pocket money. I'II do you 'mates rate' Kip if you are still in the market for it 29 years later 🤣🤣🤣 I will pin this if you don't mind Kip as I didn't do a spoiler saver, and you haven't given away the outcome. Hope your back is on the mend 👍
I remember using this and tandy wp series at school in 1995 and think aslo dreamwriter they are just a re branded variant of this but they are impossible to find in uk now
@@Mymatevince Haha.. Pin away buddy. I always try to avoid comments so it's not spoilt.
Haha.. Honestly I'd love one for the sake of retroness but we're moving house soon and I need to assess my collection of stuff 😂
Back is absolutely vile, but you know.. Gotta keep going, just at a slower pace. 😂😂
"It doesn't work, fantastic!" hehehe, that is why we like you Vince!!
Regards the fuse - yes, there's probably a diode between ground and the +ve rail (reversed biased so it does not pass current when powered correctly). If reverse polarity then goes through that diode, causing large current to be drawn which in turn blows the fuse. I fixed a number of these back in the day by just replacing the fuse. In one instance I think the diode was shorted too. Although I cannot see where the diode is there. Regards to the fuse being 250V - that's common, the voltage isn't that important here (a higher voltage rating wont be an issue), so manufacturers just go with a fuse that's available (mains rated) - but the current is the key. You will see 250V rated fuses all over the place in low voltage scenarios.
Nice one Chris, thank you! 👍🍻
Came here to say this. Reverse biased diodes don't draw that much current. Forward biased diodes which short to ground say through a resistor which allowed current to exceed fuse value but not start a fire provides protection from reverse voltage safely and only requires 2 cheap passive components.
I always look in the comments for the reliable GadgetUK comment. 👍
@@tiporari No, they did it like that because diodes have a voltage drop. Put, say, 6V through one, and only 5.6V gets out. On a battery-powered machine, you need every fraction of a volt you can, since a battery's voltage falls as it becomes more drained. Below a certain voltage stuff stops working and you need new batteries, so you want to put that off as much as possible. Therefore you don't put a diode in series to protect against reverse polarity.
Instead, you put it in parallel! Reverse-biased. So the ordinarily with normal polarity it doesn't conduct, it does nothing at all. But wrong polarity means the diode is forward-biased and will conduct, and since it's right across the power lines, it shorts them out. Causing the fuse to pop, and protecting your delicate microchips.
It's done a lot on battery-powered stuff.
@@greenaum Thank you for making this elaborate answer, I didn't get it before
I love how you got excited when you realised there was another fault than just the fuse! Another lovely looking item and a great video 👍
Thanks Steve 👍👍👍👍
Oh man, I used to have one of these back in a day for school! Used to write games in BBC basic and play them in class. They also did another model NC200 (i think), that was more laptop-like, with a disc drive (low density of course). Thanks for a blast back to the 90's.
Nice fix Vince, I use one of these every day at work for printing one-off labels with a dot matrix Citizen printer! It has been in constant use since 1992!
It'll probably last til the end of time, as long as nobody plugs the power cable in backwards, or lets the batteries leak.
Hi Vince, nice job. I had a very similar machine in 1991 but not an Amstrad. I managed to write my CV and many covering letters on a similarly small screen with attached dot matrix printer after leaving the RAF. So, well I got a job within a month! Your video brought back memories! 👀👍
The screen discoloration is a problem with the polarizer, it simply gets old and the glue detoriates. You can simply peel it off, clean the glue with IPA and put on a new one. The same happens to older Gameboys. Great job as always!
Thanks Marvel 👍👍
I was actually right thinking that as well
@@nikkic36 I'd really like to see someone produce a modern display for these: They seem like they're using something akin to the standard LCD driver, so it should be possible to produce a drop in replacement with modern screen technologies.
Can you imagine the battery life with an e-ink display?
I have watched a few of your repair vids and you have a calming way about you and your decriptions of the repair are very thorough. I must admit I have'nt a clue about repairing electrical stuff but I still enjoy these vids, especially, the Playstation stuff. I have had an X Box in the past and it overheated with a red ring of death within six months, so now, I only get Sony equipment and they've been very good from PS1 to 5.
I have watched all your videos and enjoy the way you teach by learning yourself. You are an inspiration to a large community of people who don’t have the ability to do this themselves.
👍😀
11:51 there is a little switch in the power jack that disconnects the batteries when a plug is inserted. That's also the reason this device is center-negative. They did that on nearly all battery powered devices with a DC-jack as it was the cheapest way of doing it back then. The negative is the same between DC and batteries, but the positive is either the batteries or the inserted plug.
12:36 The fuse must likely has blown due to someone sticking a center-positive plug inside the device. There will be a diode blowing the fuse if you connect power the wrong way round.
NOICE! Just sat down and Vince uploads! It is a good afternoon so far.
The vinegar smell is probably from the seller trying to neutralize basic battery leakage with an acid. So yes the battery compartment is clean as they said… because they cleaned all the corrosion out.
The same senario evolved in my noodle as well, sir.
250V is the highest voltage this fuse can interrupt (without building up an ionized path) a shortage or when the load gets too high. If the used voltage is higher you'll need special fuses - not in this case ;-) I don't know any fuse lower than 250V ...
Many devices have polarity protection, which is a combination of a fuse and a diode after it. Wrong polarity will blow the fuse - and sometimes the diode but the device is protected. They do it this way because they don't want to loose 0,7V especially in battery operated devices by inserting a diode in series (which would also protect the device without any fuse)
Thanks for another interesting fix. As others have said, a basic fuse is just the thinnest wire in a circuit which will melt if there is an overload fault. Fuses are rated by their running current, so a 500mA fuse would need pass more fault current to melt. The diameter of Copper wire to actually melt at 0.5A is about 0.04mm (using Preece equation). Your wire would go at about 0.3A, so not a bad substitute since the running current would be below this. A schottky diode (low forward voltage drop) in series with the power socket would give better reverse-polarity protection than a fuse blowing diode..
The 250V rating comes from the package insulation and the gap left after the fuse has melted, which must be enough to stop the 250V arcing across the gap. Ordinary mains fuses are filled with fine sand to quench any such arcing.
I'm off now to find my NC100 (which I bought new back in the day) and check for cmos battery corrosion...
Thank you Terry 👍👍
I had one of these when I was younger given to me by a friend. I blew it though by connecting it directly to a dynamo I made that wasn't regulated lol, I was 14 so still learning electronics. I bet it was just the fuse that needed replacing aftere watching this. Keyboard was great to use to.
Beautiful! And another nice repair, Vince!
As for the corrosion: It may be worth getting a glass fibre pen. They help a lot to remove corrosion without scratching the surface like tweezers do.
You can get them from eBay or most hobby or car stores for a few quid and they make cleaning a breeze.
Only downside: Glass fibres. So keep your workplace covered and use a vacuum and maybe gloves.
Option: There are brass versions of the same thing.
He has one
Hiya Vince. I really enjoyed this video especially. When I was at Uni in the early 1990's I used to lust after one of these Amstrad notepads. I used to stare through the window at them and curse my typewriter with memory function, that was ok to use but you could only work on one essay at a time, then print it and delete it to do another. Brought back some very good memories.
This was the machine that replaced the BBC Micro and the Acorn etc in schools, also my ol' mum had a work one as they were compatible with the Daily Mail's emerging remote access portals for journalists and she used hers when she did her degree at uni as was just so handy.
not in my upper school, they went to RM Nimbus PC ish machines, they had a couple on trial when i was in my last year there ,
Nice one Vince. Love to see more vintage computer repairs. Much better than the new stuff
A wire will act like a fuse if you exceed it's electrical load capacity. In the automotive world they actually have wires called "fusible links" which are basically fuses that look like wires.
YOUR VDS ARE SO CHILL AND YOUR SWITCH VIDS ARE SOOOOOOOOOO HELPFUL
I
Those Wickmann fuses used to go open for no reason. Philips used to use them in their video recorders from that era; often the one supplying the VFD would fail leading to no display.
Hey, it's another win for Vince! Thanks for another adventure.
What a cool little product. Great fix Vince, love you mate.
I had one of those when at college, right around that time. Used it to type up class notes when in college. Worked a treat for a couple of years. My note taking was terrible, so scatchy notes were typed up within an hour and I could print them at home.
I really thoroughly enjoy your fix videos. Thank you for them.
Fantastic computer. Alan Sugar called it ‘his baby.’ My dad has an NC100.
I remember using one of these when I was away at college. That coupled with an old dot matrix printer got me through some tight deadlines
Nice fix of a nice device. Shame it's now obsolete but to have a working one for a collector to reminisce and get all nostalgic about I reckon might fetch a pretty penny from the right person. Nice one Vince, love all your videos.
Cheers Vince. See you on the next one.
What an epic piece of history.
Great fix man!
LOL: I've never seen someone so happy to find a problem!
Remember having once of these in 1993 with a whole 128Mb of additional PCMCIA memory. Had to transfer files from a PC to the machine and back via an RS232 lead at college. Luckily got my PC down from home about 3 months later, but did a fine job whilst I needed it.
The Master Fault-Finder! Good process Vince 👍
I love his videos!! But the one thing I miss is when he opens the box and is like I THINK this is a _____. Vince got me into my PC and gaming repair and has been the inspiration for my repairs on my car!
Vince. Apply for a trade account with RS. You get 30 day payments and free delivery. Seeing that you are in the repair business you shouldn't have any issue getting an account.
The lithium battery is to maintain the contents of memory while you change the 4 alkalines.
Yup, since the RAM is where it stores all it's files.
Vince, mate.. (sorry.. couldn't help myself) there's a bit in your iFixit kit that is perfect to remove those stand off nuts on the parallel and serial ports makes your life so much easier! :)
"it's held on by... deze... nuts" 😂
Nice and easy fix Vince. This Notepad is really cool and it is in perfect condition.
Ah, no way!! I had one ( several ) of these back in the day, used to tap out short stories on the bus home from work as a teenager :) Hope you get it going :)
Hey Mike, the next video will hopefully be the Batman 1990s rc car that you sent in the previous goodie box. Hope you keeping well buddy👍
@@Mymatevince Oh wow! I'd forgotten about that one, it was a lovely looking bit of kit, but wasn't working properly, so off it came to you instead, hope it goes well :)
Wonderful fix and what a very smart piece of kit.
Vince I was surprised 😮. I remember 1992 and although there ZX Spectrum was small, it wasn’t very powerful. My wife ordered a taxi to bring home our first PC in 1992 from her job. Big as a small suitcase, windows DOS 3.1? So a small notebook must have been quite leading the pack. Interesting fix mate 👏🏻
playing with vintage electronics is also my hobby! thank you showed us nice video! I hope we will meet you with other video!
Late to the party:
These surprisingly nice little machines are usually very reliable. Overwhelmingly the most common cause of failure is people finding one in the loft without a PSU, plugging in a random PSU without checking the polarity and blowing the fuse. Happily a fuse replacement, and maybe replacing the back-bias diode across the power rails if it's shorted, is usually all that needs to be done.
Fuses: In general the rated voltage is of no importance, although it's nice if the voltage is at least equal to the local mains supply. It's the rated amperage that's the important value - that rating will be the maximum current the fuse will 'flow' before it fails. To put it another way a rain drop falls a long way (high voltage, low current) but won't do you any harm if it hits you on the head, but you'll certainly feel a bucket of water hit you (low voltage, high current).
PS: A mod I like to do with old devices that have centre negative barrels is to add a little diode bridge right at the inputs, as you might see in a bridge-rectifier. That way if anyone's daft enough not to check the barrel polarity (who hasn't?) there won't be any disasters - wish I'd done that for my extremely rare TC2068 before I unthinkingly zapped it with a Speccy PSU. *sigh* Some day I'll get round to fixing it, if I haven't zapped an irreplaceable custom IC. *double sigh*
PPS: If memory serves the batteries and barrel are indeed common but the socket is of the type that disconnects a pole when a barrel is inserted so cutting the batteries off from the PSU.
PPPS: These things make awesome little CP/M (ZCN) laptops if that's your flavour of retro sauce.
With reverse polarity, my first stop is always the fuse. Great work as usual
Love the retro electronics fixes..!
It's probably just happened with the previous owner that was selling it. Just got it, or found it somewhere else, Tried an adapter, blew the fuse. (Without realising it) Couldn't get it to work so just ebayed it, cleaned it up. Great fix. Did you know that AMS bought it Sinclair? Is funny reading about the Zilog Z80 chip used, was also used in things like Pacman etc.
Was also used in the ZX Spectrum, the Amstrad CPC, and all the good 8-bit micros back in the day! Cliff Lawson designed all of Amstrad's electronics for a long time, so he was familiar with the Z80 from the CPC. It was also the CPU in Amstrad's PCW. So had had lots of experience with it.
Nice little thing. I like the track at the end
The Armstrad had those colour keys so looked welcoming and easy to use, i remember from the computers at the time.
if you havent already seen, there was a later larger version NC200 with flip up backlit display, 3.5 inch floppy drive, and powered by C cells, you needed pretty much new cells or external power to use the floppy drive, though due to its power consumption! these also did not feed external power to charge the internal cells, but they could be modified to do so, my NC200 has been done by some previous owner
Reminds us of a portable electronic typewriter mum bought us around the same time. Bit heftier, wasn't a computer but had an LCD screen. Also has a thermal transfer ribbon type printer... Died in a fall. Wish we could remember the brand as it was a nice unit...
•quick googling later•
Best guess find is a Casiowriter CW-16
You can fix anything I love this channel
hello VINCE...another great fix..i really enjoy watching your try to fix videos and the exciting devices you always bring...please do one favor do post new videos more in less time..thanks 👍🏻
Mixing battery types like an absolute maniac.
:p
I worked on the Amstrad help desk when this was released and spoke to Jim Bowen of Bullseye fame who owned one. His lithium cell ran out and he lots all his documents on it and was not happy and was very abusive to me about it when I said you can’t get anything back. I hung up on him and then he spoke to my boss when he called back and got told the same thing. Needless to say he said he would never buy Amstrad stuff again 🤣🤣🤣
That is so cool. Nice work and thanks for the video. I really enjoy them.
For cleaning copper fields on electronics, I recommend a fiberglass bristle brush. Instead of tearing the copper plate apart with a knife. It is very helpful. In addition, when cleaning printed circuit boards, I recommend distilled water together with IPA - with an old toothbrush.
Vinegar is commonly used to clean the corrosion on battery terminals (usually penlite cells - not lithium button batteries) so my guess is the lithium battery corroded, they tried to clean it with vinegar, didn't scratch the corrosion off, and then plugged a positive centre-pin power supply or a higher voltage PSU in, and blew the fuse. That's why you smelt vinegar when you opened it!
Thanks vince for this video, a great nostagic must watch. 5* Perhaps some more AMSTRAD fixes in the future please?
Great video! Given Amstrad took over Sinclair, it’s not surprising there’s a Z80 CPU in there - Sinclair used that in most of their computers!
I used to sometimes end up in the same carriage as Sugar on the train to Brentwood where I worked as a psych nurse, an utterly poisonous individual who was just patently rude and obnoxious to anyone and everyone, he ripped off a lot of homebrew Spectrum programmers who had submitted to magazines etc for that weird Spectrum game playing landline phone without giving them even a nod of credit and was such a shame Sir Clive sold Sinclair to Sugar who proceeded to ruin the Spectrum thoroughly :(
Still have one of these. Still works considering it spent 20 years on a garage shelf.
Wow! I didn’t know you had a bit of programming experience! And even in assembly! I’ve never done programming in assembly, so that’s an unusual skill YOU have that I do not (and I’ve done C++-programming, C#-programming and a bit of Python-programming)!
The IC on the back is just a push fit, you can extract it by pulling it out with the right tool.
Great video as always
My mate vince good job
Great video really enjoyed it 👍🏻☮♥️
@18:40 That moment when a hunch pays off.. there's else nothing like it ;0)
Hey Vince! I need to pick your brain... Trying to fault find a couple of electrical things on my kids cars. I'd stop by but I'm in Kansas :) Love watching you figure these things out!
What's the problem with the car? Is it RC or a sit in and drive one?
@@shifty2755 it's the sit and drive variety. 98 Dodge Dakota, keeps blowing a fuse for the horn. I would love to know how to diagnose and find the solution.
Great vid Vince. Just an "Old TV Guy" hint for when you don't have a fuse, but need to check a board.... if you use a small incandescent light bulb, of the correct voltage (tail bulb from a car, or large flashlight bulb) it works as a break of sorts. When the current is low, the bulb won't light, and voltage passes. If there is a short, and the current jumps... the bulb will light, and drop the voltage/current to the board. In turn, saving the board. AND, you know right away if there is a problem, and you can pull power.
another great one! I would actually like to have something like this around to type.
Yes Citizen made watches, calculators, organisers etc and also made LCD screens for other companies, including Nintendo for the original Game Boy. Then the Citizen LCD screens for the cancelled colour version of the original Game Boy (yes, that was going to be a thing) went to Sega for the Game Gear!
And yeah the Z80 is the CPU in the Master System, Game Gear, SG-1000, ColecoVision etc (and secondary to the 68000 in the Mega Drive). Also used as an embedded microcontroller in all sorts of things, and as CPUs in some early 80s arcade game machines. The Game Boy / Color's CPUs are hybrids of the Zilog Z80 and the Intel 8080.
the z80 in general is actually a superset of the 8080. Zilog designed it to be binary compatible with the 8080 if memory serves. I wouldn't be surprised if the Gameboy variant had a number of changes: The 6502 variant in the NES was modified to include the sound generator and I wouldn't be surprised to see a similar change in the GB.
Hm... maybe the vinegary smell is... vinegar! As a mild acid, used to clear up the encrusted remains of a leaky alkaline battery. Could be!
I had a Z88 which was the superior Clive Sinclair-designed version of this! Very similar, rubber keyboard of course, but a very usable one, and being one rubber piece meant you could spill stuff on it and it just wiped right off. Clive's version came first, 1987. Wasn't a huge success but it's users stuck to it like glue, lots of use from people like journalists who needed a computer on the move, and one that weighed only 1KG and got 20 hours out of 4xAA batteries was a godsend back then! Rather than a laptop that weighed 4 stone and the size of a Samsonite briefcase with 25 minutes of battery and you'd have to bring the charger. If the Z88's batteries go flat, you just buy new ones! Or of course use the mains adaptor.
Very cool. I think this would have been pretty handy back then.
Always check the fuse and Cross polarity diode ( car radio cassettes, CB radios, etc, if it has one ? 73's Andy M6APJ
Mmmm, good to see the Amstrad colourscheme. Reminds me so much of my Aussie version of the CPC464 (With green screen).
Nice job Vince! Always great to see one of these get back to life!
By the way, what does the ‘Secret Menu’ button do? Just curious (:
The z80 was also in the spectrum and zx80/zx81 Amstrad 464 and many more.
That chip on the underside looks like the system rom, it looks like it is in a pcb socket.
10 FOR A = 0 TO 10
20 PRINT "HELLO"
30 NEXT A
40 PRINT "FINISHED"
Nice ZX, just tried it. I need to try out a program to see if it can play different sounds 👍👍
One of the few people I know of that’s actually happy when something is faulty 😂
Amstrad South Africa used to make FOXTEL cable/satellite boxes for the Australian market.
Hi Vince, l had same one and same problem that blow the fuse, l think was mine mistake that I put wrong transformer cosing reverse the polarity, thanks for your info always you do a great job 👍
Most common fault is someone plugs in a center positive PSU. Alan [ Sugar ] was tight with using the center negative to ensure PSU ro-orders.
I have 2 x NC200's. Great little toys.
nice would love to get my hands on one of them
The good old Z80. Used in so many things including of course ZX80/81 and Spectrum.
Not looked these up to see if it was mentioned in the manual or not, but quick observation DC jack appears to be directly connected to the battery compartment. Amstrad were well known for cheaping out as much as possible. I presume there would have been a warning in the instruction manual, but you never know with Amstrad stuff.
Amstrad did produce a superb and quite cheap 386SX with co pro monochrome laptop, very good quality and the screen albeit not colour was quite high quality for that era and it could pump out VGA to a monitor in colour. My late mother because of how Fleet St worked in the early days of remote access portals etc and the systems the papers used, ended up with quite a lot of Amstrad stuff ranging from the portable green screen PCW to a PCW512 for the locoscript and other word processing formats, had the aforementioned 386 lappy and this NC100 then she bought her first 486 which I modded for her with a co pro, extra ram, Sound Blaster, a horrible Rage Fury Maxx Pro dual GPU abomination and set it all up for her to hook her video camera equipment as she was working for the C4 company that made Dispatches by this time and had to record voice and video of superior quality which sadly Amstrad's word processing machines were not capable of doing.
Nice work! The NC100 is very interesting… It looks like Amstrad literally took Sinclair's Z88 and as they did with his other creations, re-engineered and improved it. The core similarities are far too close for it to be a coincidence - even right down to the choice of BBC BASIC. 🙂
Nice little portable computer, might have been useful indeed as a student in 1992 :)
Yes it is possible to blow the fuse with reverse polarity, that is why the fuse is there as a part of protection.
Thanks technixbul
Wow.. you don't see these things very often, if at all. The only Amstrad computer I have ever seen in my life was one that an uncle of mine had imported from England.
MMV, I’ve got one of those, Just dug mine out & thought I best check the Lithium Cell and it needs replacing as I suspected, Nicked the Battery from the Dead ASRock Motherboard that I’ve got here, It sprung to Life and just to point out that I use Rechargeable Batteries & they work fine with this even though it will only be 4.8v, Think I bought mine off eBay some time ago, I never knew that about the “Amstrad” name & thanks for that! 🙂
I did have a PenPad as well and not sure what happened to that, If I remember correctly the Casing got sticky and it was horrible, Yuk!
Just found out that the Spacebar on mine isn’t working so looks like mine needs to be looked at, Hmmm! 😂
What a surprisingly nice machine :-)
really enjoyed watching this. i guess i will get one from ebay soon ;)
That rom chip is, in fact, in a zero-profile socket.
We used something very similar in the early 2000’s in the classroom.
Honestly man, I've been following you since about day one you've started putting up things and moved away from the telco videos (I had a different account back then) but seeing how far you've come in knowledge and production quality is sooooo nice to see :) I love your channel. Keep doing what you do!! Take care.
Old video to comment on but here goes . It might be that the lithium battery corrosion was the original problem and caused that quirky fault , the owner maybe thought their power supply was faulty bought another one but with the polarity reversed and that blew the fuse
Nice one👍👍
I've seen that kind of glass fuse fail for no overcurrent in the past. And guess what one was my 1992 mural gas furnace (probably thermal cycle) and the other don't remember but probably same age device and I bought a box of spares back then.