Fixing Other People's Bad Repairs (Again)

Подписаться 67 тыс.

Просмотров 37 тыс.

50% 1

This episode is sponsored by PCBWay www.pcbway.com
Fixing computers is hard enough. But fixing computers other people tried to fix and failed... that's the stuff of nightmares and this is a perfect example of that.
Support Noel's Retro Lab on Patreon: / noelsretrolab
You can also support Noel's Retro Lab on RU-vid by joining this channel:
/ @noelsretrolab
Tools I used:
- Bench power supply amzn.to/3PdKdh4
- TOPDON thermal camera (iOS) amzn.to/45jFMa1
- TOPDON thermal camera (Android) amzn.to/45BYGZm
- Hantek oscilloscope amzn.to/3Ew2wYJ
- Amstrad diagnostics ROM github.com/llopis/amstrad-dia...
Chapters:
00:00 Intro
00:32 Power
01:06 Inspection
03:11 Voltages
04:07 Temperature
09:23 Signals
14:49 Stuck test
19:53 CRTC?
26:11 ROM
31:46 Final touches
Music tracks:
Funky Stars by McKlain mcklain.bandcamp.com/track/fu...
Battro OST by McKlain mcklain.bandcamp.com/track/ba...
More awesome music by McKlain: www.mcklain.com
🛠 Tools I use ➤ noelsretrolab.com/tools.html
Connect with Noel's Retro Lab:
Discord ➤ / discord
Facebook ➤ / noelsretrolab
Twitter ➤ / noelsretrolab
Instagram ➤ / noelsretrolab
Mailing list ➤ noelsretrolab.com
#repair #retro

Наука

Опубликовано:

3 июл 2024

Ссылка:

Скачать:

Готовим ссылку...

Добавить в:

Мой плейлист

Посмотреть позже

Комментарии : 190

@Zeal8bit 10 месяцев назад

You usually make great videos. But here, it may be your BEST video! There was everything we can expect for a complete repair: inspection with temperature scan, oscilloscope, voltmeter, then diagnostic with schematics reading, signal reading, Z80 assembly code, testing and finally trace repair, socket replacement, and chip replacement! This video must be an introduction to anyone who plans to repair a retro computer.

@jnharton 9 месяцев назад

Honestly, this one could probably have been done by a knowledgeable person without the use of a thermal camera or an oscilloscope. Having a good diagnostic cartridge and the source code listing of the diagnostic software is quite useful though. --- The best part about his videos, though, is when he explains what he is doing and why!

@paulstubbs7678 10 месяцев назад

The first thing I noticed was the big blotches around the caps around the RAM, did he cook and de-laminate it. My nightmare repair was a mate who managed to feed 240V AC up the main bus, blowing tracks of the board etc. The most amazing part of that one was the irreplaceable ROM's survived! So we fixed it. After fixing the blown tracks, we then replaced any IC's that were red hot, then we replaced any that were clap cold, this got us 95% of the way. Boy was the dead pile big. However we were working for a telco, and using their repair facility, on their time - of course. Thanks go to all the telco subs that funded us......

@evaDrepuS 10 месяцев назад

Yes, it is fun seeing the thought processes behind fixing someone else's 'fixes'.

@jnharton 9 месяцев назад

Honestly, it seems like they managed to locate most of the problem areas. Might be as minor a mistake as assuming the board traces were fine. You know aside from the melted plastic on some of those sockets. --- Many people would have missed the issue with the single-wipe sockets used for the Z80 and the gate array, given that they look fine. Thoroughly checking stuff over is tedious, but it's the only way to be sure.

@braveitor 10 месяцев назад

I admire your knowledge and patience. I'd have thrown that bad boy out of the window... :D Good job, fun to see and glad to see that you finally repaired it.

@andywest5773 9 месяцев назад

I prefer to view these mistakes as evidence of someone's journey towards becoming a great repair person, and helping to keep our hobby alive. It's easy to make fun of a botched repair job, but let's not forget that we all started with zero knowledge in the beginning. We shouldn't discourage anyone from trying and failing. That's literally what it means to gain experience.

@PhilXavierSierraJones 10 месяцев назад

I was screaming: "THE BOARD IS DELAMINATED!!!"

@Adrian_Finn 10 месяцев назад

These are my favourite type of video, love the process. Always include videos like these in your output, so entertaining.

@spacedock873 10 месяцев назад

Well done for your persistence and tenacity. You finding the intermittent socket connection reminds me of the movie "The Andromeda Strain" where the electronics technicians were looking for an electrical fault and the actual issue was a piece of paper! Turned pin sockets are not designed for multiple insertions and removals - when you first insert the IC legs they cut into the inside of the socket and effectively weld themselves, similar to what happens with wire wrapping. Unfortunately this process can only be relied upon once and after that if the leg is removed the cut can start to oxidise and will never make such good contact again. If a chip is likely to be inserted and removed multiple times it is best to use dual wipe sockets.

@jackrubin 10 месяцев назад

Thanks for sharing this walk-through. I really appreciate your perseverance and humility.

@MichaelEhling 10 месяцев назад

I so appreciate this diagnostic and repair saga: a heroic effort and win. Nicely done.

@SieIaQ 10 месяцев назад

That's why I love this channel, a real debugging!

@SnipE_mS 10 месяцев назад

This channel is great! Been finding a lot of these smaller channels lately and man are they good. Even the small touch of showing which pin your scope probe is on is just so thoughtful. Subbed!

@benbaselet2026 10 месяцев назад

Man what a journey. Some times it's appropriate to just take things apart to the atoms, check and rebuild everything. But very often that's just not needed because usually it's just a simple broken trace or chip that you just need to find. Probably a big reason why I love these repairs, you never exactly know what to expect :)

@YogSothoth1969 10 месяцев назад

So well done Noel!!!!!! Glad you fixed it, but to be honest, never got any doubt you would not get it running 😀 Greetings, Michael

@NoelsRetroLab 10 месяцев назад

Thanks 👍

@4034miguel 10 месяцев назад

These repair videos are really relaxing. I hope you continue making more. Thank you.

@minombredepila1580 10 месяцев назад

Amazing as always. These repairings are helping you to get a bulletproof tester. Congrats on the mix between the board and the code debugging: so illustrative !!!!

@nutsnproud6932 10 месяцев назад

Thanks Noel. I never thought cheap sockets are the problem.

@Wobblybob2004 10 месяцев назад

The first thing I saw was the de-lamination around the RAM. Somone used a paint stripper to get that ram out!

@NoelsRetroLab 10 месяцев назад

At first read your comment and I thought you were referring to some kind of chemical. But I think you were referring all along to applying too much heat 🤣 Yes, I think that's the most likely cause.

@M0UAW_IO83 10 месяцев назад

There's plenty of youtube videos with 'retro repair experts' delaminating boards with excess heat as they try to desolder chips using hot air and those godawful ZD918 solder suckers, not to mention their *awful* soldering when they try to put stuff back together. Still, the more they destroy, the more my restro stuff is worth

@GodmanchesterGoblin 10 месяцев назад

First thing I saw too... A major failure right there with plenty of scope for fractured vias in the PCB too. I never saw that done to a double-sided board before. Goodness knows how much heat was applied.

@michaelcarey 10 месяцев назад

Agreed, that's the first thing I saw too. Way WAY too much heat! This kind of damage will expand the PCB substrate and will break any vias in the affected area. I wouldn't even start to attempt a repair with prior "repair" work like that... but it does make for a good video 🙂

@chaysefox 10 месяцев назад

In a past life, I used to do third-level phone support for software. By the time callers reached me, it's mainly to undo and fix what previous levels had done. Boy howdy did they go off-script and do things that weren't sanctioned that I had to resolve for them.

@francescosacco4969 10 месяцев назад

It was a wonderful episode! Thank you for your hard work!

@AntonyTCurtis 10 месяцев назад

Back in the 1990s when I worked at a computer shop, we charged _extra_ for fixing computers which was a repair attempt from elsewhere.

@flexairz 10 месяцев назад

I had something similar in the past, also with a Z80 computer.. Broken via.. took me ages to find that one...

@Smanux 10 месяцев назад

Fascinating repair. You could probably modify the diagnostic rom to stop the crtc check after a number of loops and display a failure message

@8bitsinthebasement 10 месяцев назад

Always a delight when one of your videos appears in my feed. You sure showed that CPC who's boss :)

@rastislavzima 10 месяцев назад

00:26 true Noel, its very enjoyable watching somebody else having a nightmare 😂

@jaycee1980 10 месяцев назад

single wipe sockets cause SO much hassle - I replace them on sight in Amigas, whether theyre working or not !

@10p6 10 месяцев назад

Every time I try to fix an Amstrad it fails, to fit in the garbage can. lol.

@antonyshipley7552 10 месяцев назад

Not on a CPC, but in the past I have had faults that are fine when the computer is cold and then when things warm up and connections expand then the fault appears or visa versa. Intermittent faults are always the worst and require a lot more time and effort so well done on that one!

@NoelsRetroLab 10 месяцев назад

Yes, that's even worse! I haven't encountered that with expansion, but I did get a few problems that only show up after 5-10 minutes and they're a pain!

@gertsy2000 10 месяцев назад

Well done! That was a big repair. Great video.

@Nabraska49 10 месяцев назад

Yes that’s the stuff .. love the mystery and the twists of the fix .. very entertaining.. thanks mate .

@TechCowboy 10 месяцев назад

I understand your pain. I tried to repair an Amiga 2000 (my own computer) which had battery damage when I had full on cataracts. I've since had surgery and I look at it now and see I've basically destroyed the board.

@DerekWitt 10 месяцев назад

This is akin to my experiences of doing tech support (for Compaq in the late ‘90s). I once got a customer who was told by a previous tech to reformat and reinstall Windows for no sound. All he had to do… wait for it… plug in his speakers! I wish I was making this up. I don’t know who was worse: the customers calling in or some of the people I worked with. lol

@johnczaia9124 10 месяцев назад

Awesome detective work, Noel! One of the few channels I never fast forward, just too interesting all the way. And 10 extra points for the G7000 Videopac poster :) My first videogame back when.

@NoelsRetroLab 10 месяцев назад

Thanks! That's actually the label for the box containing a Videopac G7000. It was kind of getting in the way 😃

@HAGSLAB 10 месяцев назад

Very well made repair video Noel. I enjoyed that!

@LtKernelPanic 10 месяцев назад

Great video. Glad I found your channel a couple months ago. Your recent TI-84/4A video finally made me order a video cable for mine. Now I just need to dig it out and hope the power brick still works. I know PSU mine came with had the in-line transformer which are usually pretty reliable.

@menhirmike 10 месяцев назад

There is a certain… irony? to the fact that sockets are usually added to make things more maintainable, but are causing a maintenance nightmare because they were bad sockets badly installed.

@juanmiguelcortarello6823 10 месяцев назад

Excelente video! Super difícil de diagnosticar alguna de esas fallas. Felicitaciones.

@ismaelyutub 10 месяцев назад

Noel did it again. An impressive repair. Well done!

@RetroTheory 10 месяцев назад

That moment when using your code to find the bad trace on that logic IC *chef's kiss*

@tony359 10 месяцев назад

amazing repair, thank you!

@adilsongoliveira 10 месяцев назад

Yay! A Noel's video to lighten my Friday, thanks! Too bad Ic an only drool over those beautiful machines as they are next to impossible to get in Brazil :)

@BottIsNotABot 10 месяцев назад

Nice repair, well done Noel.

@rzerobzero 10 месяцев назад

I commend your patience. Great job!

@CarcharothQuijadasdelased 10 месяцев назад

Mmmmm bad sockets that fail depending on how you hold the board, almost like the classic "Is the computer plugged in? Is the cable sited all the way in?" but way more insidious and hard to diagnose. I can't imagine how hard it could be if that problem was originated on a cracked trace, doable but tedious and probably better to have a new PCB made. BTW perfect Ñ pronunciation, pretty rare on English speakers.

@rangercv4263 10 месяцев назад

I believe Noel is a native Spanish speaker and that’s why his Spanish pronunciation is perfect. He also has excellent English and I think he now lives in the United States instead of Spain.

@TheDefpom 10 месяцев назад

1:30 looks like the PCB has been hot air desoldered to socket the RAM, and this has been done too hot/too long and delaminated the PCB ripping the internal traces/vias.

@eebaker699 9 месяцев назад

Great videos! Damn those single wipe sockets....

@psteier 10 месяцев назад

Touching a PCB making it work - that's called "magic hands"... :D Nice one!

@AlanPope 10 месяцев назад

This was super. I liked the 'boss fight' analogy at the end, too :D

@DarrenHughes-Hybrid 10 месяцев назад

Nice helpful video, even though I don't own an Amstrad computer, it was still helpful to see what and how you fixed it.

@TomStorey96 10 месяцев назад

Those read/write signals might look a bit ugly, but it's important to remember that for TTL inputs generally anything around 2V and above is considered logic high, and TTL chips by spec may output a logic high anywhere as low as about 2.4V. So as strange as it may look, it may still be perfectly normal and within spec.

@GenialHarryGrout 10 месяцев назад

The flood of satisfaction the runs through you when you finally solve difficult issues

@Trevorodunne 10 месяцев назад

Just shows how skilled you are, Love the videos Noel.

@laurentvoisin8129 10 месяцев назад

Impressive video as usually now ! 😮. Thx.

@KolliRail 10 месяцев назад

Great! I would never have solved that.

@benarcher372 10 месяцев назад

Nice video! Thank you so much.

@TotoGuy-Original 10 месяцев назад

well done for getting it working. great video id like to see more repairs they are interesting

@mlann2333 10 месяцев назад

Great debugging, well done.

@Bianchi77 10 месяцев назад

Nice video, well done, thanks for sharing :)

@logonsystem6791 10 месяцев назад

Very interesting! It feels like following an investigation to find the criminal(s) 🙂

@NoelsRetroLab 10 месяцев назад

Well, that was my friend, who has since told me he wishes to remain anonymous (for obvious reasons 🤣🤣🤣).

@JakeBirkett 8 месяцев назад

Ah the most comfy T-shirt ever, Steam Dev Days (2016 dark blue edition). I think that might have been the last time I saw you unless you went to GDC in 2017/18.

@NoelsRetroLab 8 месяцев назад

Right??? One of the best t-shirts ever! I haven't been to GDC in over a decade, so yeah, that was the last time. You need to come by if you're ever in the East Coast!

@JakeBirkett 8 месяцев назад

@@NoelsRetroLab Will do!

@magnusterminus4728 10 месяцев назад

Amazing job you did there🎉

@djmips 10 месяцев назад

Nice effort! Do you think it would be a good idea to change your diagnostic ROM to time out on the VBL and report that as a possible issue with the VBL line?

@alexanderwei7211 10 месяцев назад

Oh my! That is some serious delamination on that poor mainboard!

@flomojo2u 10 месяцев назад

Been there, done that! Except I'm usually the idiot who messes it up the first time around, trying to hurry through the troubleshooting process.

@erwindewit4073 10 месяцев назад

I'm truly impressed! That you actually got it to work properly! Wow! I also hope you weren't in Spain in the past months with the 40++C temperatures...

@NoelsRetroLab 10 месяцев назад

Thanks! No, I've been back in the US for a couple of weeks so I missed it. Phew!

@hansu-nihon 10 месяцев назад

Noel, I hope you are able to bring us more videos on a regular basis as I like your channel very much. However I can understand with your work and move to the US it's not always easy.

@TRONMAGNUM2099 10 месяцев назад

Thanks! Some good tips I'm going to use to try and get my reproduction board up and running.

@NoelsRetroLab 10 месяцев назад

Thank you! I'm sure you'll be able to get the repro board working. Just keep plugging at it and learning.

@DerIchBinDa 10 месяцев назад

I always enjoy your videos and is one of the evening highlights when I sit down and watch it with some snacks and enjoy your skills. You really have a great talent to explain what you are doing and what you expect happening. Are you back in the US by the way? Greeting from Germany!

@NoelsRetroLab 10 месяцев назад

Yes, I've been back in the US for a few weeks already (this video was actually recorded before my previous one, so things are a bit out of order).

@rager1969 10 месяцев назад

Wow, great job. I'm both liking and subscribing.

@NoelsRetroLab 10 месяцев назад

Thank you and welcome aboard!

@VincentGroenewold 10 месяцев назад

Wow, I mean I'd like to solder on my Amiga, but I'm going to make sure I practice a lot first on a random board. Also, it amazes me that the person didn't think how he/she might be the cause looking at the work itself. :)

@Johadart 10 месяцев назад

Wow, after all that fixing up other people’s mishaps!!! It’s working , great job, keep up the great content mate. 🤙🏼🇦🇺 Joe from Australia 🤙🏼🇦🇺

@awilliams1701 10 месяцев назад

This video is a perfect example of why sometimes you need a working machine to fix a broken one. With my C64 I had to fix it blindly. The ram wasn't too hard. I knew exactly which one it was, but I replaced all 8 because it was mt ram. But then I had this wierd glitch. I for the life of me couldn't figure it out. I replaced the color ram. The PLA. Eventually I realized the voltage dropped too much but only when I had my U2+ cart installed. Then I realized my home made PSU didn't have thick enough wiring. That's all it was. New wiring = works fine....until the cartridge port gave up the ghost. De-oxit had been working for a while. But eventually de-oxit wasn't enough. I replaced it and the system is fine now. If I had another C64 that worked, I could have tested the color ram and the PLA.

@NoelsRetroLab 10 месяцев назад

That is so true. People underestimate how important is to have a working one side by side. If nothing else, it helps me to learn the signal patterns under certain conditions and then you can backtrack into why something isn't working.

@theplateisbad1332 10 месяцев назад

Interesting that the disc-type capacitors were replaced by MLCCs. Typically they are quite robust, unless the disc cracks or so. And the MLCCs derate their capacity with rising voltage. It's probably no issue here, but I would have used discs again, especially since they are still in production.

@anvz6 10 месяцев назад

In some point of the program you should do a loop waiting for vsync but counting and report an error indicating vsync never received.

@NoelsRetroLab 10 месяцев назад

That's a really good idea. Just generally extending it to check all the PPI ports possible would be great too, but I may need to design a harness for that. Not sure.

@dolomighty74 10 месяцев назад

or even a beep turned on before the loops, and off after

@anvz6 10 месяцев назад

@@NoelsRetroLab At least the vsync is something you can detect easily, and it would tell you there may be a problem in ppi or vdp

@pathnkalex921 10 месяцев назад

Interesting. Thank you.

@FrankDrebin 10 месяцев назад

17:37 when desoldering pin 10 you can see some sparks. I don't think this is normal.

@NoelsRetroLab 10 месяцев назад

I hadn't noticed until you mentioned. Those are definitely not sparks, but they do look like it. I think it's the melted solder and as I press the trigger, it flashes by for a split second, creating that illusion.

@FrankDrebin 10 месяцев назад

@@NoelsRetroLab "Sparks" could be a wrong word, but this definitely looks like discharge, it's clearly visible on freeze frame. You may have some grounding issues in desoldering gun.

@bradnelson3595 10 месяцев назад

It wasn't one of mine. :) But I kinda-sorta do have an Atari 2600 in similar condition that needs fixing. Let me know if you want to tackle that. That said, I was able to fix two other 2600's so I'm not a complete nim. But great job on that computer. That was fun to watch.

@Angel-wn2mu 10 месяцев назад

Magnífico como siempre. Una pena perder de España un crack nivel Dios como tú.

@minesapola05 Месяц назад

Los demás mortales daríamos lo que fuera por esa habilidad para comprender el sistema eléctrico de un ordenador. Felicidades eres un artista

@peteblazar5515 10 месяцев назад

When a craft changes to art.

@Vamptonius 2 месяца назад

A Phillips VideoPac, nobody else has ever heard of one of those. My Stone Sling cheats.

@Breakfast_of_Champions 10 месяцев назад

Wow that was a pretty shoddy first attempt by your friend. Well done!

@lepompier132 10 месяцев назад

That would mean that someone that tried to fix this computer probably did not have the old school knowledge of the era that PC came from. like installing a socket that wasn't used when that computer was originally built. I remember in late 70's, 80's and 90's, wen you used sockets that was for prototyping in electronics. And that was why they soldered IC chip to the PCB back in those days, improving the electrical connection. And also back in the day, they used lead in the solder, now you need to find new old stock of roll of solder with lead content. If not you are stuck using the new friendly solder, but you need to use flux to make sure the solder will flow and make a secure electrical connection. And that is why often we have to fix broken traces on PCB.

@andywest5773 9 месяцев назад

Not sure what you mean about the solder. New 63/37 solder is easy to find and I use it all the time. Can't stand the lead-free stuff. I think sockets are used more on old machines now because the chips are old and going bad, so it makes things easier to work on. You didn't really have that problem forty years ago when they were new.

@MrVipeg 10 месяцев назад

Thank you for very interesting video, second one in a row. Looks like Spain-based videos turn out much more interesting than US-based for quite some time. Hope it going too change in future, so US-based video become as good as this one.

@idio-syncrasy 6 месяцев назад

Well done. 🎉

@Pippo.Langstrumpf 10 месяцев назад

Ever tried to clean corroded contacts with flux? Flux is made for that too!

@petersrensen5972 10 месяцев назад

Did you ever try the 16k eprom that came with the machine? Maybe it is a program for controlling some proprietary hardware connected to the CPC? (some old machine of some sort)

@JRJJ5077 10 месяцев назад

That looks like a really bad PCB delamination issue near the ram chips.... 🤔

@NoelsRetroLab 10 месяцев назад

I noticed that too and recorded some comments about it, but ended up cutting them from the final edit because I didn't see anything obviously wrong there and I've never seen any products cause that. I'm curious what it was though.

@ReneKnuvers74rk 10 месяцев назад

Aren’t the gate array and the Z80 working fine and was it just the el cheapo sockets that were the culprit?

@falksweden 10 месяцев назад

I'm always fascinated when people try to repair something by butchering it violently. So far I have never seen a computer where the initial problem was that it wasn't butchered enough 😁

@Nukle0n 10 месяцев назад

There's a fine line between confidence and fool's confidence, and then not being confident at all. It looks like someone tried to fix this, only made it worse, they went down the wrong path and it went worse and worse until they eventually gave up. Sometimes that's how people learn.

@Waccoon 10 месяцев назад

And with through-hole stuff, no less. I can understand SMD repairs going wrong, but you have to be really careless to damage so much on an old 2-layer board.

@Nukle0n 10 месяцев назад

@@Waccoon it's called a hardware store soldering iron that gets 600 degrees hot, meant for brazing together roofing drains. Temperature controlled soldering irons are thankfully getting more widespread but lots of people try and do soldering on irons really only meant for wire splicing.

@alexwierzbowsky 10 месяцев назад

Hi Noel, nice repair, as always! Where did you get that nice tool that you used to remove Z80 at 30:50?

@NoelsRetroLab 10 месяцев назад

Thanks! I don't know. I think it's called a crow bar chip lifter or something like that? It's just like a screwdriver with a curved tip. I don't know if it's exactly the same, but search for Wiha Precision Chip Lifter on Amazon and you can go from there.

@djmips 10 месяцев назад

Why at 20:50 does it say UNKNOWN CPC - is this because it doesn't know until it gets further along in the test but was blocked by the endless loop for Vsync check?

@tenminutetokyo2643 10 месяцев назад

Not those crappy Amazon caps!

@swishersweet3756 10 месяцев назад

Great video, thank you Noel.

@WacKEDmaN 10 месяцев назад

the discoloration on the board is bit how ya doing.. looks like flux that has got into the board.. probably not much of an issue with no internal traces.. but still not good... nice troubleshooting Noel..ive seen the same sort of thing from a single pin on the GA having a bad connection on the socket.. machine would run, but would randomly reboot itself..changed socket and its been rock solid ever since

@NoelsRetroLab 10 месяцев назад

Yeah, I didn't see anything obviously wrong with that part of the board, but the discoloration was odd. I don't think you can do that just with rough soldering though. I wonder how it happened.

@WacKEDmaN 10 месяцев назад

@@NoelsRetroLab2 ways ive seen (with an old board that ive ripped all the components off!).. heat! these board really dont like it.. they are just fibreglass afterall!..you'll usually see scorch marks tho... or flux has seeped into the board

@benbaselet2026 10 месяцев назад

@@NoelsRetroLab I'd have to guess someone read bad forum posts and tried whatever disastrous chemicals they happened to have around the house. "magic cures" are all too common in the more religious part of the flock.

@bzuidgeest 10 месяцев назад

Voltage regulators like the 78xx need a few volts to do their work. So if there is a 7805 in there you should supply it with 6v or so from the bench power supply. That way it has something to work with. You cannot set the bench power supply to 5v and expect the regulator to still supply 5v.

@GODAXEN 10 месяцев назад

More likely a minimun of 7 volts is needed for a stable 5v output, there are versions that are stable with as low as a 5.5v but that is very dependent of the current.

@WacKEDmaN 10 месяцев назад

no regulators anywhere on the original CPCs!..power coming directly from CC/CV bench power supply... always a bit of voltage drop on the board...

@bzuidgeest 10 месяцев назад

@@WacKEDmaN I'm not that familiar with the board, but Noel talks in the video like there is one on the board. But even if there isn't, it's a general statement and valid for any place where a regulator is used.

@WacKEDmaN 10 месяцев назад

@@bzuidgeest ..he said there is no regulators!.. and even put some words on the screen....

@bzuidgeest 10 месяцев назад

@@WacKEDmaN relax, it's always possible I misunderstood him. Instead of focusing on the presence or not of a vintage regulator. Let me ask you this (again). Do you want to claim that my general statement about the working of voltage regulators is in any way wrong? If not, then what are you really bitching about?

@douro20 10 месяцев назад

Will a CMOS Z80 work? I know the CMOS version doesn't support the undocumented opcodes found in the older NMOS version.

@nyanpasu64 10 месяцев назад

Would plugging in the power supply with the wrong polarity fry the chips in the way observed? Did you ever check that the voltage sag was gone at the end?

@NoelsRetroLab 10 месяцев назад

Good questions. Normally plugging it in with wrong polarity (or a 9V one) would fry the RAM and maybe the Z80. That's what I've seen in the past. Not the GA and other chips. But everything is possible! I didn't check the voltage drop at the end, because I know that with my PSU, for whatever reason, it's always around 4.6V or so, which seems really low. With a plain wall wart I get rock solid 5V, so go figure.