Commodore 1541 Floppy Drive Repair - pt 1 

The dark lines at the end of the video (and other parts) are my camera's sensor overheating. I use a Nikon D5300 and it is not "meant" for video. So it isn't well suited to the task. I'll just preempt some comments by saying, no I cannot actively cool the camera in any way. Cold boxes for stellar photography are the closest I could get, but that isn't a real solution for having to shoot video all the time. It would be extremely impractical.

@AkBKukU Contrary to your last line, a video about debugging old hardware without solving it at first try is pretty good. Not every case of repair needs to be sugar coated to be enjoyable to follow.

What you need is a Dead Test Cartridge! It will test all chips, and show what is working properly and what isn't. They are pretty cheap on Ebay and very useful to have :) It's been a long time since I powered on my 1541, but I'm pretty sure the power light normally blink when powered when not connected to a computer.

I've never seen a chip jump out of its socket before.

I feel like this is the first unboxing video I've seen that featured the contents of the box being poked with a stick :D

Here in Europe, especially in the former eastern block like Hungary, the datasette was the goto storage device for the c64. The floppy drive was really expensive, so not many people had it.

I became an expert on Commodore stuff around age 10. My school had upgraded from C64's to Apple IIGS's but there were never any good games to take advantage of the IIGS -- just crappy old MECC stuff and other things for the //e. I found copies of Pole Position, that Super Mario knockoff, and others for the C64. Somehow I became somewhat popular during the winter months because I figured out how to play video games in school. Never being a very social social person I preferred the machines instead of people during recess -- the Commodores in particular. We had stacks of classic C64s and a few 128s, 1541 and 1702 drives, etc. I'd take them apart, figure out what was wrong, swap components around, even met my first girlfriend this way by showing her electronics. In the end my principal sold me every system (including the 1702 monitors) for $1/piece. Also... The appropriate drive for your C64 would be the 1541 mk II. It matches the case and might be easier to repair should you get the serial working. Great video as usual!

Not sure if it's been mentioned already, but the "Device not Present" error can be caused not only from a faulty CIA #1 (U1), faulty 6510 CPU or resistors at R28, R29, and R30, but can also be caused by a bad 7406 Logic chip (U8). This chip is soldered in and not part of the standard chips to swap when troubleshooting. Disregard the comment about the 7406 logic chip if your board assembly is 250469. Great video.

34:33 Aaiieee! Don't plug anything in to a C64 while the power is on! That's exactly how CIA chips die.

This might be useful for future repairs but I discovered that the plastic of c64's (and a lot of old home consoles too like the NES) can be repaired using Tamiya modellers plastic cement, it's about the same price as super glue for a huge quantity given how little you need. It takes longer to bond than super glue but it reconnects the pieces on a molecular level so strongly that it's often the case that if it does break again it'll break somewhere entirely different, if applied cleanly you can sometimes get it to look as if it never broke in the first place. For screw posts and any part of a casing that is likely to be stressed this kind of repair is massively more preferable as super glue gets increasingly more crystalline and brittle as it ages or gets hot and cold.

This video was awesome! Having problems, failing at something makes you many times learn even more! And actually, you can even make watching a paint dry interesting, dont worry about that.

The number "1541" will always be special to me because of using this drive back in the 80s.

Thank you for including all the experiments, troubleshooting, and issues. It's really great to see somebody going through the same sorts of issues most of us deal with when restoring hardware, rather than everything working perfectly after a montage. Warts and all, makes for a nice video. 👍

I really liked seeing how you diagnosed the issues on this Commodore. As a repair technician I really appreciate seeing how people figure out what is wrong with something. Keep up the good work and I can't wait for your next videos!

for grounding points I would have sanded the paint off around the area you intended to place solder.. just the way I'd do it.

That was a fun video, seeing the whole process is always fascinating.

The potted power supplies on these are ticking timebombs.

This video was GREAT! I am a huge fan of the Commodore 64, it was my first computer and I still play on it from time to time. Your frustrations with it all just made me laugh out loud, so thanks for sharing!

I'm watching this in March and I enjoyed this video! You working on old stuff is enjoyable and fun even if you don't succeed. Just watching someone who knows what he's doing troubleshoot is good content and fun!

Perfect timing with this video. I've got a 1541 and 1571 that are partially working I need to fix.

Great video, as usual. Keep 'em coming!

Thanks for posting this. I'm sorry you didn't get it working but the way you presented everything just had me laughing the whole time, especially that chip that leaped from its socket. Pure gold 🤣 Better luck with part two.

Dude! I love your sense of humor! Don't loose it: 0:47! Great video!

Don't feel bad about this video man, failures(or non successful attempts) are just as important to show as the perfect "I fixed it!" videos.

I didn't like that chassis tinning at all, screw thread would do the job just fine, and ensure good contact with chassis ground. Second thing is - you had the donor C-64, so you had the spare serial connector, why didn't you use it? Last thing - de-soldering pump you're using really is a garbage. I mean - I had worse, but this isn't any good. I know a very good pump, but it is local Polish product - it is called ZEL OD-25. If you're really into THT repairs, you should consider buying ZD-915 de-soldering station or something similar.

I went out and bought an older Commodore 64 and two 1541 Floppy drives(both drives were from different people in different states initially looked good both powered up but one would spin a disk the other would not)none have been tested and a 1702 Monitor which is tested is coming next week so your video is very helpful from a troubleshooting standpoint. I would say the best thing I took away from this is to really make sure all connections are solid. In Adrian's Digital Basement he has a video where he got a C64 to work that had been protected by ants it was rusted and dirty and been in a field for decades and he got it to work.

great vid because seeing you try and error - this helps a lot of us

Fwiw, Ray Carlsen has excellent repair guides for these machines.

Great video ! I've sen that you helped Adrian Black with his power suply adapter for his 5150. Thanks for another great video. Keep them comming please :)

Dude the video was great! Just because you didn't fix it doesn't mean it was bad. The information was good and it shows the troubleshooting process. Keep up the great videos! Wish I still had some of the old PCs I used to play with years ago - sadly they got recycled :-/

Hahaha, what a gem of a video. 40 minutes of repair to repair nothing, must have been AMAZING to edit it

The second CIA chip is what controls the serial ports. you should focus on the second one to troubleshoot. Also, look at the C64 wiki, you can find a ton of info on everything on the computer there. Good luck!

I'm actually completely ok with videos that detail debugging and failures. It not only helps you but us as the viewers to give us experience in what not to do or what steps that go nowhere. Some of this can probably be applied to other projects somehow as well. Sometimes things don't go according to plan and I'm completely ok with that. As long as you say it's a part 1 of it. That way it signals people that the finished product won't be in this video.

I enjoyed it in that I could well relate to your mounting frustration and inability to confirm anything is working because of lack of parts.

Around 1985, I accidentaly became a small town part-time tech for fixing Commodore 64s and the notorious 1541 disk drives. The guy who sold them locally gave me a service manual folder for the 1541 (I think it's still downstairs somewhere in the electronics dungeon) and it has all the schematics, the step by step fault guide including a couple of programs you typed in to help (if the drive was cactus) and more importantly there were alignment disks with sinewaves recorded on various tracks so you could step it out from the end stop and look with a CRO at the incoming waves from the head. The biggest fault for the 1541 at the time was copy protected games chattering the head up against the end stop. Those games would just bash the stepper up against the stop for a while as a part of the protection. Unfortunately, the stepper shaft was just press fitted on to the cog attached to the metal band and it would move. The permanent cure was to remove the stepper and drill a pin through the shaft and cog to lock it into position then rotate the motor till the waves looked right again. Did that to around 100 of them.

Have a pair of 1541's under my C64. One works okay. The other one is a recent purchase from an 'antiques and collectable' store. Managed to purchase it for $15. Owner of the store mentioned it was "NOS". (actually....no) But it did have the transport card in place and is in amazing condition. It works 100%.

Keep in mind you have two of the 20-30+ million Commodore 64's made. Granted, that's 100% of all C64's from your perspective, but to say they are poor is misleading to someone who isn't familiar with them watching your channel. I could also say that the 5 Commodore 64's I have (that all work) means they are all stellar from my perspective. We would both be wrong. Don't give up hope on the C64. There's a reason they made 30 million of them. Despite their issues. And, if you really want to see a troublesome Commodore line, try repairing any of the TED based units.

I enjoyed the video! :)

your William Shatner impression is spot on

I really enjoyed this video, and it's funny bc these things happen to me all the times where I can't know for sure what is wrong and I'm doing nothing in reality but I actually enjoyed and learned seeing you. I actually love Commodore but I don't have any Commodore hardware (yet), I'd love to have anything, a c64 or something (and I'm like you, not wanting to pay ship costs for these things bc they weigh a lot) but where I live, microcomputers weren't a deal at all, so, it's very difficult to spot one, and when one shows up like on ebay near me, its like a fully restored one and they ask some hundreds of euros, so, still hoping to find one on my local 2nd hand store tbh. Looking forward for part 2.

34:43 what's up with the video quality ? do you have a radioactivity problem ? some weird purples stuff is showing up on the video

For that metal case I would suggest metal polish- works WAY better than the stuff you had- for such light stuff you might even get away with "brasso" or "silvo"

I like the sped up parts of the process, most content creators just talk about their process with incremental shots but this way it has way more continuity

I have the same drive and i wzs measuring the voltages and suddenly a rectifier blew up, the room full of smoke, 1 of yhe 2 pin round ones with thepassive cooler blew up. On the left rectifier i am measuring 3,3 volts dc and the right one 19 volts dc?

thanks you helped me repair my 1541. Greetings from Germany

I appreciated this video... last weekend i attempted to replace the Bounres filters in my mac SE because it wouldn't read or format floppy disks but was perfect in every other way. The only thing i succeeded in doing is making it completely unstable and prone to crashing ARGH. Sometimes this is just how it is.

All the other usual suspects treat these old C64's like they're holy relics, this bloke pokes it with a stick and speaks his mind. A different take is sometimes refreshing.

Lol, I've enjoyed it, you've put a lot of time into this, no doubts, and hopes you got the raspberry thing to work so you have a "100% known good device" to "debug" with!

I have a C64C somewhere, disassembled, that allegedly had some bad something on it. Never fixed it. I'd ship it your way if I can find it, I'll keep my eye out next time I'm in storage.

Doesn't have a spare DIN connector....just finished showing us the donor C64C.... :-D

Why use solder to try to reset the electrical connectivity of the chassis after painting, when you could just use a file or/and sandpaper?

I really enjoyed the part about the disk retention rod.

What I have done in the past with repairing plastic parts on C64/1541 cases is to use Cyanoacrylate (SuperGlue) and layer very small strips of tissue paper across the break into the drying glue. This forms a reinforced bond, like fiberglass. It can be quite tricky to do, but the resultant bond ends up being VERY strong.

hahah actually i enjoyed the video i love the way to explain and work then there was the incredible jumping IC lol

14:50 my guess? its the rust under the zinc coated steel. and since you abraded the zinc coating away it exposes the rusted steel underneath it. hence why you cant remove it no matter how much u scrub it

Back in the mid 1980's I was doing component level repair of C64 and 1541 drives. If I got a C64, first thing I would do was socket the ROM. Then I had a special ROM with some really low level diagnostics. For 95% of all repairs, I found there to be one of three problems. The 6510 processor, a PLD chip or one of the 64x1 DRAM s. The diagnostics had one test that would blink an output on the user port at about 1 Hz. I had an LED I would plug into the user port. If it blinked, that established that I had a clock and a working processor. Then I checked the memory. There were 8 64x1 DRAM chips. The memory test would indicate which one failed. If the processor and memory were OK, it was better than even odds that the PLD chip had gone bad. For the remaining 5%, I just the replaced the board. I was thinking of getting a digital logic analyzer but I finally just gave it up. For the 1541's I got an exerciser. The 1541 didn't have a home position sensor so to move the head to the zero position, it would run the stepping motor the full number of steps in reverse. So for a certain number of steps it would "bump" against the zero position stop. After time, I think the stator would become magnetized enough so that it would be a step off even after trying to bump the head to the zero position. The solution was pretty simple. Unbolt the step motor and turn it 90 degrees. Then it would zero. That seem to fix the problem on most 1541's. Then I would charge customers 40$ to "repair" their 1541. $40 was usually what I charged to repair a C64. Once all they wanted was a new C64 case. I asked, "what happened to the old case". They said it was destroyed as the result of a karate chop. I had a few extra cases lying around so I sold them one. After about a year of repairing Commodore equipment, this is basically everything I learned.

How do you get off the rf shield? I tried solder whick and a solder sucker but it didn’t work

Barkeeper's friend contains oxalic acid, any acid will cause etching of oxidized metal. Many rust treatments are based on phosphoric acid, which converts iron oxide into iron phosphate, a dark gray/black substance. White vinegar will also convert rust into a dark gray schmutz, I assume it's iron acetate, since that's acetic acid.

onwards and upwards dude! you only get better if you try new things and persist! keep at it!

31:52 It turns on and seems normal, but if you look closer, cursor does not blink. C64 KERNAL(or maybe BASIC) uses timer in one of the CIA chips to blink cursor.

Haha, wow, that's crazy about the power supplies. I never pictured having to plug 2 power plugs in to run the same computer!

I got up early today. Then I've found this video (came here from the super glue and baking soda trick video). Now I know what to do for the pre-work relax. :) PS.Subscribed. Because your channel deserves at least this. :)

37:41 I could not stop replaying that lmao

You said "cavity search" and my mind went somewhere other than teeth...

Another C64 + 1541 is back to life!!!:D

where you tried to lay down solder for grounding, consider removing ALL coatings from the metal for the solder - use something like a dremel and wire brush or grinder to get to raw metal. then use some flux too. cheers.

Close your eyes and you can actually hear Kermit repairing the floppy drive. Jokes aside, great video.

Next time give Evaporust a shot. Submerge it for 24 hours, and maybe hit it with a 3 or 4/0 steel wool on the really bad bits. That stuff works wonders for me.

Finally another commodore video

I remember fixing that latch pin on a couple drives I had back in the 90's. It can work itself out even when the drive isn't dropped.

I enjoyed this video

I have a unitrex 1200 would it have the chip you were talking about?

Good luck in part 2!

Curious if there was ever a part 2 of this?

Cyanoacrylate superglue does not work with ABS plastics! It just melts it a bit and deforms the piece, smoothing the stumps away so it's even harder to fix it with epoxy later. Always check glue compatibility before glueing, but the gist of it is that superglue is not good for most things related to computers, and 2-part epoxy is where it's at. Wood glue is also useful sometimes for non-load bearing parts because of its mildness and space-filling properties. Also, there was really no need to apply the solder to the case, even if no ground connection is made (and the screws will make it) there won't be any problem. All parts that need to be grounded together will have ground leads in the connecting cable anyway, it's bad practice in design to use chassis ground for signals. And I did very much enjoy the video!

Dang dude, that's tough. Hope you get stuff sorted out.

Interesting that "cmd3" would work as well. I remember using "cmd4" but I saw another guy print something with 3. I also thought the "open" was something like 4, 4, or 4, 4, 4, but this other guy used 3, 4 also. I think it's weird that we should have to open the channels for printing or for advanced disk commands anyway, rather than just having them open by default, because even with them open already, the stuff doesn't go to the printer until you "cmd3" or "cmd4" anyway. And with the disk drive I never needed to use the close command to help anything, even though they have it, so I don't see the point of that.

MOS and Mostek are two different companies. Also if you have a VIC20 you can test the drive with that.

You can't always have success with every project. Even this video was a fun journey to watch, at least for me.

If you have a device not present error on the printer try device 5 (both are usually used for printers). Your disk drive is in fact communicating with the C64. When you do the LOAD"$",8 you are getting the SEARCHING FOR $ message and not a ?DEVICE NOT PRESENT ERROR in addition to it. Also, little known fact, a Commodore 64 can actually support 23 disk drives, but it gets tricky after 4. While a Commodore disk drive can be set in hardware to device 8, 9, 10, or 11, you can actually set the device ID up to 30 in software. It would take a bit of work, but you can automate it somewhat (you can write a basic program).

I enjoyed it anyway because knowing what doesnt work (trial and error) is always needed during troubleshooting

oh man, the video glitches at the end scared the hell out of me! i had just upgraded the gpu in my laptop and i thought it was already failing lol

Instead of soldering over the metal shield for the grounding, you could just take a little bit of sand paper and sand away the clear coat in those particular places.

I suspect the black in the corners of the drive cage is where the metal plating is peeling away, but that’s exposed metal and could use that sealer. And the solder isn’t trying to stick to the paint, it’s not hot enough on the metal and those are ‘cold’ solder joints. It’ll probably be fine.

The top shield seems to be more of a rarity. Keep it if you sell the drive. You will find many, in great condition, that don't have one. So use it for one of them.

Did we ever get a part 2? I was bored re-watching older videos and I realized I don't remember there being a part 2 and I couldn't find it in the video listing. If we didn't I think it's a tad overdue isn't it? I want to see him fix the shell and superglue and baking soda the front and see it reading disks. I know this moment in time isn't the best time with all that's going on behind the scenes but I hope it's at least on the near horizon. Thanks for being awesome.

Thanks for another great video. Please please get an air compressor. Canned air is a joke. Even if you get a small one for air brushing will do the job you want. Toothbrush + air compressor = dust free components. As for the oxidization you came across i think a simple anode cathode bath would have done the trick for replating your mount. edit:If you arent into replating a small rotary buffing tool would do the job just as well

And this is why my retrocomputing ends at emulation. With old hardware you're just buying into a world of hurt, and I don't have the patience =) So respect to the AkBkuku, 8-bit Guy, and the others who tinker with hardware AND by some magic, get it all running.

my drives work with standard midi 5 pin din cables ??

seems like i stocked up on commodore 64 setups at the right time way back.

You have an older style C64 motherboard. All the older style motherboards are very unreliable and many chips in those are prone to failure. However, the later so called short boards, produced from about 1987 and onwards, which are much smaller motherboards and have way less chips and are way more reliable. These newer short boards are the most common to find on ebay. They are also cheap. At least here in Europe it's easy to find PAL versions. Not sure how common they would be in America and NTSC. But if you want a far more reliable C64 then just get one of these short boards. They are named 250469 and comes in 4 different revisions. Rev.3, 4, A and B. All four are almost identical and all are reliable. So you cannot go wrong with any of them.

Use scotch-brite pads to remove surface rust/corrosion. It will remove any plating on the metal, which would usually prevent corrosion, but it doesn't look like it has any cadmium plating or anything on it, since it's still silvery and not a golden color.

When I repaired the 1571 drive for my C128, I placed a dab of super glue on the small metal rod to keep it from shifting again. This was at the recommendation of Ray Carlsen. If you Google him, you’ll find his webpage provides a lot of great info for these old Commodores, but he also makes and sells replacement PSUs, cables, etc.

definately the left cia chip was working in all cases, as when it was removed the cursor didn't blink. but it did blink for all 3.

i wonder if lanotec would help protect it ?

Nice, the case alone goes for $25 bucks. I recently bought one off eBay and made an external USB DVD burner out of it.

In the late '90s my father had a similar issue with the serial port of his c64... turned out that the DIN socket had two line-breaks between it and the CIAs.

Ethernet cable comes to the rescue again! I swear I've used it for many more things than intended.

Actually, I have several old 1541 drives that had the belt go bad. They do stretch over time and lose their grip on the motor spindle. It was bad enough that while the hub spindle would turn, a floppy disk had enough internal friction to overcome it and it wouldn't spin at all. So, I bought a bunch of replacement belts and that completely fixed the problem. Even some drives I didn't know would work turned out to work fine because they were able to spin the disk properly. Here's a link to the belts: console5.com/store/commodore-1541-floppy-drive-spindle-belt.html The replacement belts don't have reinforcement threads in them like the originals had, but they are good quality and seem to work fine. Only time will tell how long lived they are compared to he originals, because I have several drives that work fine with original belts. By the way, when it comes to doing plastic repair on Commodore stuff, I recommend Loctite plastic bonding system. It works far better and holds far stronger than superglue for the ABS plastic Commodore used.

That station have another c64 inside :P Whole europe used a tape + cartrige ( turbo loader) like action or something + screwdrive to set up the heads because they go haywire once per loading ;P