EEVblog #385 - Amstrad NC100 Notepad Repair

More retro computer time!
Repair of a 1992 vintage Amstrad NC100 Notepad
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[crazyboycashier]

long time viewer, first time poster. F301 is notorious at blewing. I worked in a school and repaired 12 of these (all with same issue)

[MrMikeHawkey]

Thanks for this video.  I was upset recently when I put batteries in my NC100 and tried to turn it on, only to find it didn't.  I watched your video to get some ideas, and would you believe that my problem was also the fuse.  It must decay over time, as it was working when I put it away a couple of years ago.  Thanks again.

[ForViewingOnly]

Hi Dave, thanks for this video. I know you have to cater for everybody but I would definitely appreciate more videos on fault-finding retro computers (using a scope to find problems with old CPUs and logic chips, etc.). Thanks.

[NaokisRC]

I like how you are so enthusiastic about trying to find a difficult fault and find it disappointing it's such a simple one. Granted most faults usually are simple but still love it. Tempted to send one of my broken pieces of electronics for you to mess about with but I hope it wouldn't take months for it to arrive!

[enigmaticengineer]

Love the old school computing, sub 20mhz mostly, vids you do. Commenting at 40 seconds into the video, I know I'll enjoy it. If you ever want something 'Tandy - Radio Shack' to play with, let me know and we'll work something out. Thanks for the fun and all around awesome videos. Now I can rewind the vid and watch what I missed lol.

[deelkar]

I find it more amazing that they became 3 orders of magnitude faster while only using about one magnitude more power

[CoolDudeClem]

I used one of those at school because my handwriting was so slow I couldn't keep up with everyone else. I still remember programming it to play pong so while they thought I was working I was just goofing off!

[ales_xy]

6:35 - 6:40 C340 soldered only by one end? (reference is in the block on the left of the ROM chip)

[enigmaticengineer]

Very cool. I have CoCo 2's and 3's, hacked and factory stock...I collect and enjoy them...if you ever have a particular want when it comes to Old School computing, I scoop up everything I find here in the US without discrimination and I'm not looking for profit, just keeping the legacy stuff running well. Thanks again for the excellent videos.

[msjaxp]

Hi Dave,
Your videos are fascinating, but in my opinion, most of viewers, including me :) are hoping to give us some additional lectures about making and design embedded and electronic circuits, you may have, like for example how to make complex FPGA systems or how to make a double sided circuit at home, ... etc
Anything you may have in your huge knowledge will be very useful to us, even it was some ridiculous for you.
And I assure the number of viewers will be extremely high.

[jeromequelin]

I love the strategically placed tantalizing µSupply schematics cameos at around 10:00 and 10:54 ;-)

[andygozzo]

useful thing to note, if you have one of these that doesnt power up, check and if necessary replace the fuse (wickmann type, 0.5amp, if i remember correctly..?
) that some versions of these use(different from the one in the video) as these seem to fail due to age, seem to form some sort of 'fungus' in/on them which rots the internal wire...maybe the version using smd fuse has similar problem!

[EEVblog]

That used to be the case, but now this blog is my day job.

[msjaxp]

Okay Dave, thanks for replay :)
I hope to see more videos from you soon

[camelCased]

"Sagan was here." <- this is great :D 15:07

[JHarding]

Although many devices today can consume much more energy than before, devices have become much more efficient. Back in the 90's there were computers that used 65W, just as your notebook, but they could only calculate far less in a certain amount of time. And besides that, this is an energy efficient portable device from the 90s, that as you stated uses about two watts... which is what an iPhone consumes today.

[bencollins]

I think it’s common for these to have blown fuses because the DC power supply socket has the positive on the outside. People find a wall DC plug that fits, but as most of them are negative on the outside, they blow the fuse.

[whiskeyify]

good video..I especially liked the part where you viewed some of the signals with the ocilloscope.

[SeekerofYab]

6v @ .3A = 1.8W
Those things really didn't take much to run at all. Its amazing how laptops have gone from that to things like the 65W notebook i'm watching this video on. I know today's computers do a whole lot more, but its just mind-boggling to look at raw differences like that.

[bytefree]

Perhaps they put the Z80 just to be able to run the BBC Basic ... could be ? ... like the C128 running a Z80 appart from the MOS6502, just for the CP/M compatibility