When Projects Go REALLY Wrong

yeah, we all love success stories and clean soldering but personally i admire most creators who share their failures for us all to learn. Great job and fantastic final product Noel!

Surprising how few people here recognise the root cause of the difficulty you had getting solder to bond with the IC legs, but it's very simple actually. You could see those off-colour, dull looking legs from across the room. Loads of corrosion and/or some sort of dirty build-up. Fresh tip: don't bother trying to solder onto corroded / dirty metal. Solder needs to actually contact the metal surface, and the metal surface of course needs to be at a similar temperature to the melting point of your solder at the point of contact. Careful mechanical abrasion is usually what you need! Like, a small square of medium / fine grit sandpaper held with tweezers. Or just the blade of an X-acto knife. Then scrub with a bit of IPA, dry it off, and get to work. Sometimes only the scrub is needed, with an organic solvent (IPA, acetone, MEK) if you just need to displace some tacky or oily dirt. There is the option of using an active flux. These are usually acidic (often phosphoric acid!), and typically not noticeably aggressive at room temperature. But, with the heat of the iron the acid gets angry and can eat through most corrosion. Some active fluxes are very active and will easily eat through Fe2O3 (red rust), and your soldering iron tip. Note, however, that you must clean active flux residue off VERY thoroughly. And I do mean VERY thoroughly. Any residue hiding, say, under an SMD component, will destroy whatever it's touching (starting with exposed contacts and copper traces) over the course of the next few months / years. It will catch you out. Not recommended for this kind of work.

The Avrdude correctly reported that it probably is an m8 chip (ATMega8). The Avrdude has a pretty comprehensive list of device IDs.

Atmega8 is a legacy chip, it was used in many projects years ago, then a next generation Atmega88 appeared (along with others from the family) adding more features and improving existing peripherals. Guess someone in China had a batch of then-cheap Atmega8 chips, and they did what they often do: renamed them as a "better" Atmega88. There was a point when new AVR microcontrollers were expensive and scarce, maybe this is the reason?

If pins are so oxidized that they refuse solder, clean them off the board. Many of those solder connections of the fake chips still looked not connected well even after your last attempt. As for wires, do yourself a favor and get a spool of wire wrap wire. That is great for all wire connections that must be thin. They only need to be tinned before using, because they are not meant to be soldered.

You forgot the basic number 1 rule of soldering.... heat the pin AND pad at the same time while touching the solder to the pin.... when the pin is hot enough the solder wil melt and flow properly to the pin and pad and the joint will be smootth and shiny.

Those first chips looked like they were made in 2010. They have had plenty of time to corrode, especially if they have not been stored properly. You can actually see the difference compared to the new ones. The old ones are grey and ugly, while the new ones are nice and shiny. The bad soldering was not your fault.

Welcome back, Noel. I was a bit worried about you after so much time. Thanks for another great video!

4:45 the first mistake is tinning more than one pad. That way the IC can never be flush with the rest of the pads. Only one pad must be tinned, allowing for the IC to be held in place. Solder only one pin while pushing the IC into position, then check the alignment. If the alignment is correct, solder the pin diagonally opposite to secure it in place. Then go for the others.

I'm an electronic technician who specialises in rebuilding and restoring older machines, like Neumann matrices engravers for vinyl mastering, as an example. I understand the frustration that comes with that kind of work. I spent a couple of days searching for intermittent trouble in a machine I just finished to rebuild. Since the client and I had already invested 10k in time and parts, I wasn't allowed to give up, I found the trouble, but man, do it get frustrating sometimes, lol 😅

If these are harvested and re-branded chips, the harvesting process may have subjected the leads to far more heat than is normal. This could cause damage to the silicon (hence the bad chip you found) and/or so heavily oxidize the solder on the leads that they become extremely difficult to solder. This is the reason I only buy from Digikey or other reputable sources.

Hey Noel! So, I'm about 7 minutes in. You first mistake with respect to soldering the chip is you DID NOT heat the pins themselves. Solder sticks to hot metal, it really doesn't like to stick to cool surfaces. A bigger tip DEFINITELY would help here, your general technique is great though. You probably could use hot air here. I'll update via comments my notes to you.

The important part of soldering is to heat up both pieces of metal to be joined at the same time. Applying the tip of the iron just to the pad isn't heating up the pin, therefore you won't get a good joint.

Lots of good info in the comments on the specifics here, but as a guide for other who may be hobbyist solderers(?) from someone who does a lot of nano and micro rework by hand as a job: I use tips way bigger and iron temperatures way hotter than you would assume for any given task. Plus, not all tools and materials (station, tips, solder, flux etc) are born equal. I have helped beginners who's starter soldering kits make things additionally hard for them and me! One tip when using a monocular scope/screen is that pins can look OK from the top down and a decent nudge test is the only way to check, and absolutely soak the pins in the first place.

Oh boy. I went through 6 pairs of Darlingtons and 4 rare Schottky diodes and finally blew a loudspeaker from replacing power transistors with Chinesium ones. Then I bought UK sourced ones from a reputable supplier, a replacement voice coil from the USA and finally got an old Fender guitar amplifier singing. Like you, I wondered why would they bother to rebadge scrap at such low prices? Then I remembered how Sir Clive Sinclair started in business...repackaging scrap transistors and reselling them as 'special' ...

Some chips are harder to solder than others. What stands out to me is that you only heat the pad and not the pin. For the best results, you need to heat both the pad and the IC pin with the soldering iron. If you don't touch the IC pin, it will be at a lower temperature and won't pull solder onto it. Additionally, if it's an older IC that wasn't stored properly, there may be some oxidation on the pins, so it's essential to burn that off with flux. Therefore, heating the IC pin is crucial for successful soldering.

Ugh, what a frustrating mess! Excellent persistence, and thanks for the shout out!

Great to have you back. I felt your pain. My tip to check SMD solder joints: hold the board at a shallow angle and look through a magnifier. If the joint is good you’ll see a shiny ramp of solder from the pad to the pin. If you see anything else (ie a step) the joint is bad. Since discovering that I’ve not had a duff joint.

This is a great lesson in problem-solving. It also warns us to be careful about the chips we buy. Most counterfeits that I have seen have blurry lettering and incorrect logos. Try to find images of genuine chips online and compare. Another great takeaway from this video is that there is now a new source of SID chips for the Commodore community. Hats off to whoever created it.

One of the most braindead things in Windows USB drivers is that they are port specific. It is to me completely absurd that the device gets treated differently in a different port. I mean, it is good to have that as a possibility, but not as a default! This has been the way since at least Windows XP (probably even in older versions), and you can e.g. see Windows installing new drivers whenever you plug a device to a port where it wasn't before. This is particularly problematic when the default drivers don't work out of the box... I think Microsoft doesn't really know what the "U" in USB stands for.