How to fix an 8-bit computer with only cheap tools 

Quick tip for the ground and voltage pads that have large planes - cut the braid at a 45 degree angle, put the sharp end into the hole and apply the iron. The sharp corner will get in there deeper and it works much better than just applying heat to the braid as the whole braid is over the hole. Hopefully that makes sense.

I used a soldapullt for 10 years fixing avionics with through hole components. Now that I work with just SMD, I use a microscope and a thin braid: there's almost no space for a desoldering gun. A hot air gun with a small nozzle and thermal tape work like a treat. I also bought some of that Chip Quik you showed in another video and that made a huge difference in desoldering large ICs!

Adrian, this is probably the best video in a long time. The extra effort to take the added steps to prove your hypothesis were just awesome. Love the focus of using cheap tools, obviously not practical for you always, but lets us know you care about those of us who want to try this out without spending a ton of money. Can't say anything else but thank you for this video.

Another great video. Your videos encouraged me to have a go at fixing my Atari ST. To my amazement I got it all working (socketing a RAM chip much like here) and have since repaired other machines. I love the detail you have in these videos showing exactly how to take out chips, what temp to set the iron to, how to install sockets etc. Fantastic, keep up the good work. :) Only advice I would add from my experiences is... get an old piece of electronics that is unfixable and practice taking chips, caps, etc off it and soldering sockets etc on and off until you feel more comfortable with solder, flux, wick, solder suckers etc

Great info for those of us that don’t have expensive equipment,and don’t do enough to justify buying them I have a Hantek oscilloscope coming. Now I know to get the open source software.

Really Great Video Adrian - I love that you focussed this on amateurs using basic tools. I would love to hear more details about the diagnostic process - e.g. more about what the various buses do and why you expect signals to look a certain way. Glad your hand is back in action. I bet Hantek would sponsor you - sales will probably spike after this.

Quality but inexpensive tools? A hundred dollars or so. Adrian's world-class diagnostic skills? Priceless.

Soldapult hint. Keep the iron on the edge of the hole and bring the soldpult on the top of the tip of the iron, and covering the hole you are trying to clear. Works great, and for really stubborn ones, put the iron on the via on the bottom of the board and use the soldapult from the top.

Someone must have mentioned the Engineer SS-02 desolder tool with the silicon end ? That has quickly taken over as my favourite desolder device. Then wick and third my duratool desolder station. Glad so see you back after the operation.

Love the shirt, I'd be shouting take my money for a "It Freakin' Works" one! I've been using the 6022 with open hantek software for a while, but it's my first ever scope so I really appreciated seeing someone with more experience make the most of it, some great tips and helps me loads, cheers! Super video for us casual repairists to see you do your thing with our humble tools, so thanks. Cheers!

Desoldering machines are worth their weight in gold when working on through hole ICs I also agree with your choice of socket, the round hole ones are far superior.

Thanks for the great video - nice to see the repair from a "normal user" point of view without 200Mhz oscilloscope available! :) I hope your hand gets better soon!

This is the video I needed! Finally have a starting point to try some probing 😂, so happy I’m a Patreon! And the surgery video was so funny 😂

Btw: you can make your own logic tracer with just some hookup wire, two 1k resistors (for CMOS), or two 270-330 ohm resistors (for TTL), one of those red/green bi-color LEDs (the kind with two leads), some alligator clips (one red, one black), and a small, sharp nail (or a probe tip from a set of ratty test leads you no longer use.) Wire the probe tip to the red cathode/green anode of the LED, then wire the other end of the LED (the red anode/green cathode) to the junction of the two resistors. Now connect some black hookup wire to the black (booted) alligator clip and to the other end of either resistor, then connect the red hookup wire to the red (booted) alligator clip, and to the remaining, unconnected, resistor lead. Solder, and heat-shrink, all your connections, and find a suitable holder (such as the barrel of a (dead/gutted) felt-tip marker, or something similarly cylindrical with about a 1” diameter. Route the two (red/black) wires out the back of the old marker pen (drill a hole big enough, though), then seal with hot glue. The tricky part is securing the sharp probe tip in the other end of the marker pen (where the “felt” came out.) This part MUST be mechanically sturdy, because you’re going to be pushing on it during regular use; so use 5-minute epoxy, not hot glue! To use, just connect the black alligator clip to circuit ground of the device-under-test, and the red clip to the positive supply rail.. Now verify by touching the probe to ground. The red LED (logic low) should light. Then touch to B+; the green LED (logic high) should light. If you now touch the probe to a signal alternating between low and high, you’ll either see yellow (frequency > 10 Hz, 50% duty cycle), alternating red/green (frequency < 10 Hz, from about 20-80% duty cycle), or somewhere between full red to full green (frequency > 10 Hz, between 20-80% duty cycle) If the LED doesn’t light at all, then either the point has a broken circuit trace, or is high-impedance (such as a bus transceiver). Theory of operation: when the probe tip is unconnected (or at Hi-Z) the junction between the two resistors will be B+/2 volts with equal resistance resistors, and no current flow through the LED. When you connect the tip to circuit ground (logic low), the (electron) current flows from ground, through the LED red cathode/green anode, to the upper resistor, and out through B+; the red LED lights. Likewise, when you connect the probe tip to B+ (logic high), the current flows from ground, through the lower resistor to the LED green cathode/red anode, to B+; the green LED lights. Finally, when you connect it to a signal that alternates between ground and B+, the red/green LEDs take turns lighting up. At low frequencies, you can see the individual colors; at higher frequencies, the human persistence-of-vision causes us to see yellow (just like a “yellow” pixel on a CRT monitor is a red and green one lighting at the same time.) (at least, if you don’t have red/green color blindness!)

this was the best advert for getting a desolder gun ever

Thank you for making me feel better about how difficult I find it to desolder things.

i know he's getting that a lot- but im really glad i found this channel! Amazing content + i love how he explains everything! Please dont be afraid to take a break when needed!

If I may make a suggestion, I'd recommend leaving the iron on the joint. It shouldn't hurt the desoldering pump and it'll keep the joint hot until your ready to pull out the solder. I'd also add just a little flux to the opposite side of the PCB. It helps keep it from oxidizing and it'll flow better. As for what magically happened may simply been a cold solder joint.

I have replaced many a part using the methods you show. The worst case I've had to resort to is use a tiny dril bit. Doing this is not recommended generally, but being carefull it does work. I don't do a lot of repairs anymore being retired, watching you brings back memories.

Always enjoy the content Adrian

Thanks for the tips and guide for removing chips from a motherboard and the showing of ease of use of cheap tools. Great video!

Nice video man. I'm just a weekend hack but I can't endorse enough your comment about good quality braid. I thought braid was just junk until I bought a reputable brand from Amazon and it was worlds apart.

As someone who has a major interest in the restoration/preservation of old technology [specifically computers and CRT monitors] but haven’t had the ability to get hands-on due to money problems, I REALLY really appreciate this video because I can collect these items to use eventually until I have the money to upgrade :] 💙💜💙💜

Really valuable troubleshooting skills demonstrated here, and with cheap tools as well - very nice video indeed!

When I was doing my electronics degree about 20 years ago, our teacher taught us to hold the tip on the Soldapullt (we called them "solder suckers") on top of the tip of your soldering iron until you melt a small channel into the side of it. Then you could hold your iron on the pad, put the solder sucker over the iron, (mostly) seal the top of the pad with the plastic tip, and then punch the button to clear the via.

Awesome! Thanks for using the cheaper tools for diagnosis.. Some of us part time DIYers can really use this kind of video!

Several decades ago when I fixed electronics for a living my employer supplied a vacuum desoldering station, but I never really liked it since it constantly required the cotton wicking in the glass recovery tube to be cleaned or replaced. They were also ridiculously expensive. On a trip to one of the hobby electronics stores in Toronto at the time I discovered an inexpensive desoldering iron, which is basically a solder sucker mechanism integrated into a soldering iron handle. It worked at least as well as the expensive pro desoldering station, only needed to have the sucked solder emptied every so often, and still works perfectly probably 35 years after I bought it... and it's still on the original hollow tip!!! The beauty is that you don't have to remove the heat from the joint before you trigger the suction. I haven't picked up a separate iron and sucker in decades. After watching your video I wondered if similar tools are still available, and it turns out they are, although most (all?) of them are Chinesium and probably inferior to the one I bought all those years ago, even though they look identical to my vintage one. All the ones I could find quickly seem to be 220V, even the ones that claim to have a "US plug", but a more serious search would probably turn up a 120V one. Here's a couple of quick links... www.ebay.com/itm/383025969157 www.geekbuying.com/item/TNI-U-TU-842A-2-in-1-30W-Desoldering-Pump-Soldering-Iron---Black---Blue-361363.html www.aliexpress.com/item/32838841550.html This one just looks like the same tool as the other links branded in Velleman livery. opencircuit.shop/Product/Velleman-Vacuum-desoldering-pump-heater-30W There are some slightly different designs available too... www.aliexpress.com/item/4000630061631.html

Really like the edit on this video. The 4 video feeds looked great and helped for referencing whilst you were probing. Keep it up!

You've convinced me to give one of these a go. I've been getting by with a logic analyser and a bucket of optimism for my homebrew builds (

Ok, for 60$ and with the Open-Hantek-Software it's worth the price. Thank you for showing this again! Greetings, Doc64!

It is because of Adrian that I was inspired to build my Commodore 64 test system using all the ZIF sockets. I have started refurbishing C64s and want to thank Adrian for the inspiration.

It's good to see you back at making new videos! I'm glad your hand is recovering well.

When I started working as a photocopier tech in New Zealand in 1995, I knew very little about photocopiers but I had many years of experience on electronic faultfinding and repair in UK. There was one tech who worked on the colour copiers and I saw him trying to unsolder chips that were blown, literally, with holes in them. I suggested that he cut the pins by the chip body and then unsolder the pins individually to avoid damaging the thin tracks on the board. He could not believe that a Pom could teach him anything, but was proved wrong. He did have the grace to thank me later!

@32:39 The peaks after the trigger is that of the 4th character line of the start up screen (64K RAM SYSTEM 38911 BASIC BYTES FREE) and by the looks of it it is the 5th line from the top of that (line 29 of the screen). The horizontal line of the number 4 is visible but not from 6, 8, 3, or 9.

Interesting seeing a repair with basic tools appropriate for someone just getting into retro repairs

It's nice to see the use of lower cost tools and associated methods to diagnose and repair. This helped me immensely!

I love the Soldapult! While it's twice a much as a cheap Radio Shack pump, its design is a huge time saver! By placing a trash can directly to my left, I was able to press the plunger against my breastplate to eject the solder waste and rearm the pump in one gesture without having to set down and pick up the iron each time. Once I had nailed the motion I was de-soldering as quickly as I did when I borrowed my friend's $280 Hakko 808 de-soldering gun. I did finally break down and order my own de-soldering gun as I stared down more stubborn ground planes and more keyboard projects with hundreds of joints, but if you are only doing a small repair once every couple months, it's a fantastic budget alternative to the electronic de-soldering guns.

Adrian, since we are all commenting on our desoldering skills I'll pile on with a suggestion of clipping the leads on one side of the DIP and the bend the chip back and forth to snap the legs off the opposite side. It's a real time saver on larger ICs. Keep the the great content coming. Thanks.

Ouch! Hope you're recovering nicely and will be all healed up soon.

If you are going to use the manual solder sucker, I strongly recommend you get one of the newer ones that has the silicone tube on the end. That can be placed over the hole while still in contact with the soldering iron tip! Excellent tool!

34:11 To further support your theory that the unregulated 9VAC wasn't working, did you notice the two system clocks also weren't counting up there? But then they were working again later

Hi - A suggestion on using the Soldapullt a technician friend taught me. Cut a small vee notch in the Soldapullt tip; small enough so the Soldapullt tip can cover the tip of the soldering iron. This allows you to keep the iron in contact with the PC board pads while operating the Soldapullt. I've been using this technique for most of my career as an engineering technician with great success.

If you're looking for a better desoldering pup, I *really* recommend the engineer SS-02, it has a heat-resistant replaceable tip that conforms to the hole you're pulling solder from and works waaaay better than the hard tip desoldering pumps

I bought a soldering iron and pump in one that works just like that manual pump, it was around 15$ but it works really well

One of your best beginner's video!

Can't thank you enough for doing a second video on the hantech last week I bit the bullet and bought one I was really glad you used the new Open source software on this video. Haven't had a chance to check out my scope yet but I was glad to see it in action on the newest software out there it is a relief to see it is going to work just fine for the application I wanted it for. Excellent video

Nice work. I had to diagnose dead C64 of my friend - same symptoms, hot DRAM, but still not working after replacement. The bus with known good chips was still driven low on some bits. Long story short - both CIAs needed replacement together with kernal ROM. In the end SID was also dead, so SwinSID was placed in this machine. That board ended as test machine then as half of the chips is now socketed :-D The scope I used was something similar like your Hantek - an OWON 4 channel USB scope.

Adrian once again proves that the most important tool you can own is your mind

great to have you back Adrian

This is a very useful video. I don't feel as bad now when I'm having a hard time trying to remove solder with braid. It really shows just how useful better tools are.

Two tips for the manual soldering pump (I have a very similar one): Firstly the plastic at the tip is quite heat-resistant, so it's perfectly fine to leave the iron in place on the edge of the pad and briefly bring the sucker into contact with the iron to keep the solder as hot as possible when you trigger it. Secondly, it tends to get gummed up with the sucked-out solder and flux after not too long, so be sure to dump it out regularly, and also find a tool (like a small screwdriver) of appropriate size to shove down the tip so you can clear any gummy plugs of solder that get stuck there occasionally. With these two tips, using the manual pump isn't too bad. You can get pretty fast with it and it's great for through-holes. Since it isn't a consumable like the wick, it's a bit cheaper to use, too. I use braid for cleaning up pads/holes once the bulk of the solder is removed, or for the odd stubborn hole, but the wick is not great at clearing a hole that still has a pin in it (if you haven't cut the leads like you did here) which the pump can manage fairly well.

It's funny -- I was literally thinking two weeks ago to pick up a cheap oscilloscope that I could hook up to a larger screen for my questionable eyes. Even with the crashes I think this unit plus the open source software is a real winner for the community. Thanks for the review!

Aneng AN8009 (almost identical to AN8008) was actually my first purchase on AliExpress ever, and I'm seriously impressed by this device, especially considering its resolution for the price. It was really hard to get, or seriously overpriced in Poland.

Congrats on 128K subscribers, Adrian! 256K will be here before you know it.

Good video, good job of fixing! If I cut the pins, I then use a solder sucker. (blue hand pump) It takes a little practice, but it t will remove the pin and solder in one operation without removing the pads. Put the sucker tip next to the target at an angle, add the iron to heat, pull iron out, tip & fire immediately. You were correct to add more solder, as it allows the air to grab it better. Reason it works better than braid is less heat time on the traces. And your iron is a bit underpowered for this size board. Braid is better for some things and not so good on others. You have to learn what to use where and when.

They also make manual desoldering irons with rubber bulbs on them that are fairly inexpensive ($20 or so) and generally do a good job. They work more less in the same way as your Hakko desoldering iron, in that they're soldering irons with a hole in the tip that it sucks molten solder into, but they just have a a bulb you have to squeeze instead of a pump. Edit: Looks like they make them with spring-powered suckers now, too, in addition to the rubber bulb ones.

Hey Adrian, I don't actually own a C64 and never have, but I find your repair videos interesting nonetheless. I have another possible explanation for why that cassette interface didn't work until you unsoldered the TO-92 transistor. Most BJTs in TO-92 cases have the base on one end of the line of leads, the collector in the middle, and the emitter on the other end. This means it is quite easy for solder blobs to short emitter to base, which would show exactly the symptoms you encountered. Even if that transistor didn't have too much solder on the pads and hadn't been reworked in the past, there is a phenomenon called "tin whiskers" which can affect solder over time, especially after the 4 decades since the C64 was originally released. Due to molecular idiosyncrasies of elemental tin, tiny "whiskers" can grow outward, and sometimes create short circuits. If the current through the short is high they will usually burn themselves off right away, but the low current drawn through that pullup resistor to ground through a whisker probably wouldn't' be enough to clear them away. These whiskers are tiny and usually not visible without a fair amount of magnification. Soldering would melt the whisker back onto the pad, and even probing with the meter might also have cleared the short, leading you to believe there was no E-C short affecting operation. It could be a marginal transistor as you surmised, but heating a borderline one like that usually makes it fail even worse rather than fixing it.

Great video, I have a tip for solder suckers. Cut a small notch in the tip so it fits over your iron tip. It will then get a bit of a seal and suck air through the board and you can suck the solder with heat still applied. This is a mod we made day one in our Lab Practices classes back in the day

For the solder sucker, they do make incredibly cheap soldering irons, like for $15, that are combined with a solder sucker, so the soldering iron itself has hole at the tip of the iron and a pump, so you don't have to remove the iron from the solder to suck it up, which gets rid of the problem if it rehardening and having to be quick. These things are pretty useful for a cheap way to desolder a lot of stuff.

Fantastic video. I really enjoyed watching you methodically troubleshoot the problems. Also very impressed with that Hantek USB scope and the much improved open source software. Thanks for posting!

MAGIC! That was a great video, Sir. Thanks.

22:50 - I believe the trick is to *not* remove the soldering iron before you trigger the Solder-Pult! Yes, it'll melt the tip a little, but you can buy bags of replacements for not much money.

One of my favorite cheap tools for computer repair is a portable AM radio. It's even good for single board computers and "system on a chip" units. Bringing an AM radio close to a functioning computer will give you noise through the speaker. This noise changes depending on which parts of a program are involved in the main software loop. Anything that causes the program to branch will change the noise, so shorting various pins will change the noise. Short out suspect data and address pins and if the noise doesn't change you have confirmation that the pin is (probably) dead. Admittedly a crude tool, but one that has bailed me out several times when no other test equipment was available.

New subscriber here . I'm getting interested in electronics mainly to repair my old consoles but at the moment I'm a noob lol . Great videos keep up the good work

The interrupt test checks the timer interrupt of the CIA. With the 9VAC missing, the timer won't run, so no interrupt is triggered. It all fits together. All there was wrong was the 9VAC missing. (well, and the RAM)

Excellent video, one of the best in a while.

This shows quite well why cheap tool repairs - while possible - are so much riskier and harder than with more specialist tools. Especially with vintage, hard to replace components. People, start with cheap tools to get you going, but then piece by piece replace the cheap stuff with specialist stuff.

Tip for easier work with the manual style suction desolderers - apply fresh solder, then put the board on it's end, with some helping hands or conveniently located objects of some sort. Then apply heat to one side of the board WHILE you do the suction on the other. Gets those tricky pads much easier, especially on the evil solder that CBM used back in the day. Then if you have to do more than one or two, get yourself a Hakko. Once you get the hang of that, it blows everything out of the water, as long as you keep it clean.

The Aneng 8008 is a good one, the Q10 as its successor is even nicer!

You do a great job of explaining the benefits of better quality tools while showing how to make these more entry level tools work. It can be tough when you’re new to a hobby to know what tools are best for you at that time. Spend too little and you might get frustrated and quit. Spend too much and you might end up with something overkill you only use occasionally. I tend to buy higher quality tools used which has worked out well so far.

Adrian, you make it look so easy.

I tried to use one of the cheap all-plastic solder suckers and never had much luck. Adafruit has one that uses silicone tubing for the tip and I found it to be a lot more effective. Because it's silicone you can push it right onto the soldering tip and suck before removing the heat. If you do wear out the tip you can just cut off a fresh 1/2" of tubing and swap it out. Not a Hakko, but a definate improvement

I almost bought one of those Hantek USB scopes but in the end I bought a Rigol DS1054. The newer batches have all the features enabled except the 100MHz, which can be hacked using well known methods. That 3rd party software for the Hantek really looks very clean though. One of the problems I've found with the Rigol is that the trace can sometimes be very glitchy in the higher scan rates. Amazing vid Adrian, thank u!

Ive had a lot of luck using solder suckers when you heat from one side and suck from the opposite side. You can even suck pin remnants out of the hole along with the solder. Only have to heat the board once. Like your videos, i'm a commodore owner from their beginning. Still have a PET, Vic-20 and 64 along with a bunch of chips (NOS). Like to see you keep them alive.

Good job! I love tools! Even cheap ones! As long as they work!

I love Augat machined-pin sockets. Great for repairs or new builds.

I'd greatly recommend the Engineer SS-02 solder sucker pump. I got it when I got my hakko fx888D and it's FANTASTIC. It's a lot smaller than the one you're using, and while it's a bit more expensive, i found it worked amazing. It's also constructed really well. I also have solder wick of a few widths when necessary, MG chemicals of course.

Get well soon! I hope you make a full recovery.

One other advantage is that this equipment also fits in a smaller space. If you don't do this often, you can store it compactly. It's also more portable. It's weird that the cassette problem went away. I did notice that the clocks didn't seem to be working in the diagnostics when the error showed up, then were working when the error vaporized. I wonder if the CIA chip is marginal. Regardless, this was a very informative video. I had kind of written off the Hantek because of the issues you mentioned with the software that came with the device. However, the OSS project that improves the software substantially is going to make me take a much closer look. Thanks for this great video!

Happy your doing good brother happy your back at it again 👍🏽

Great video Adrian. I'd be quite interested in a wee teardown of that Hantek, perhaps with some scope on scope action to see whether the higher sample rates are problematic due to the front end or due to the chipset/USB

Thanks so much Adrian! I've long wanted to do what you do on YT, but I was always sure your tools were WAY too expensive than what I could afford. Now even I can afford a 60 dollar scope!

glad you made a second video on this scope...I watched the first and after that I was like ok he got through it didn't seem to like it but it would work...here a software swap seemed to make a huge difference...yea I fall into the category of wanting to do some some soldering and troubleshooting but it's not my main focus nor do I want to make it that...so high end equipment doesn't make sense...but junk is sometimes just that...no good to anyone.

I use a Tektronix TDS3054 I bought for $20 broken. The only problem was the front panel plug was half off the PCB inside which rendered the buttons inoperable. As a bonus it has a module with GPIB, Serial, and VGA monitor out. It uses 3.5" floppy disks for storage .. so retro :). Really like the repair videos so keep them up.

Always amazing videos! Deeply thanks :)

Nice repair tutorial!!! I new a new SID chip so I'll have to see which one is correct and find a reputable source! Thanks!

I highly recommend solder pumps with flexible silicone tips - you can put them right over the solder tip and they work much better than pumps with hard plastic tips.

I'm trying to fix a c64 too! Such fun

Try this. Place the circuit board up on its side (Hold it with a clamp if needed) apply heat on one side and use the pump on the other side. This works well in a lot of cases.

Nice job. Well diagnosed. Shows you don't need hundreds or thousands of dollar equipment to fix things.

Awesome video! I clicked the like button a few more times.

For inspecting the board, the lens assemblies from projection TVs or video projectors are really good, and they are nice and large too.

Glad your surgery went well!

Awesome video. thanks for all the time, tips you put into your videos. .

Well, I'm completely sold on that Hantek. It's amazing the difference the right software can make. I also picked up a couple of troubleshooting tips from this video too, so thanks for that. BTW I suspect I won't be the only person to say this, but is it possible that small transistor may have had a bad solder joint? Could be why the circuit started working once you'd resoldered it into place.

Nice job. I think the heat cycle on that transistor woke it up.

Adrian is a far better technician than I am. And I consider myself to be good.

Could you do more of these types of videos? I'd love to see a series "Adrian challenges himself to fix: X with only Y!"

I replaced a video RAM chip on an NES in the past year for a friend and I used my Soldapult solder sucker to get the bad chip to slide right out easily. Didn't cut any pins or add any solder. The trick is to have a good tip on the solder puller to have a good seal on the hole to clear it. Then I clipped Pin 4 on the 10NES lockout chip. I bought my solder puller at a HAMfest years ago.

Back when I could hold a soldering iron steady enough, I would clamp the board in a vice, put the solder sucker on the top side of the motherboard. Then I would apply the heat to the bottom of the board. Would suck the hole clean every time. This way you are still applying heat when you use the suction device..