Thanks for posting this

Seems like a lot of work when you could just use a tool made for this like a desoldering gun.

I've removed chips on a ton of these boards (and even older PCBs from the 70s) and almost never do any damage with just a soldering iron and spring pump. Seems like the amount of time you need to heat the board to push the pins out (not to mention having a dremel that close!) are a much bigger risk than just doing it the normal way.

Back before I got desoldering tools, I'd just clip the chip body off the legs with some small wire cutters and then pull them out with forceps while heating, so I really don't see what the need for the dremel and all that set up is.

I second that, I used the desoldering pump a lot. Finally purchased a desoldering gun holy crap life is sooooo much easier.
usually the IC's come out undamaged almost 100% of the time.

Replacing headers on the other hand, almost 40% of the eyelets come out with them. Mainly have issues with that generation of board, which leaves you to either run some wire braid or replace the eyelet.

I just use a desoldering gun. The trick is to heat the leg, then touch the pad and circle around the leg while sucking, then pull away. So, you won't be in contact with a pad for more than a second or two, and won't ruin anything

Really appreciate sharing the technique. I think each person will find what works for them, but the trick is that this all takes practice, no matter what you choose.

There are tons of people that swear by a $10 solder sucker. There are people that love solder wick. Personally I invested in a Hakko desoldering gun and love it. I actually tried the dremel technique once and I do have a bit of a shake in my hands, so one quiver and you're ripping through a trace.

Love and appreciate the detailed pictures and walkthrough though...awesome writeup!

no, I've damaged pads and lifted traces by using the iron/pump technique. Part of the reason why I opted for the gun.

think when you heat it with an iron w/ a soldering pump you might have to do it multiple times and at longer durations. (which increases the chances of damage).

a desolding gun takes like 2 seconds and usually only one time is needed. it's a lot more expensive then a 10 dollar pump. Taking less risk and the time savings make it probably one of the best tools in kit.
I know they have tweezers as well for IC chips and SMD's.

I can do about the same with a $15 pump and $30 temp controlled soldering station. 2 seconds per attempt, maybe 1/20 needs a second sweep (usually ones on ground planes that suck up the heat), and I leave the pad while I work the rest of the pins so it has some time to cool down. I've got a gun too and I have about the same success rate, but I keep getting the gun clogged somehow so I tend to avoid it, but I'm sure that's something with my gun cleaning regimen.

I think your tricks work better for acid damaged boards.

Don’t let this place deter you. This is good information and people can pick the method that words the best for them. But I know that I’m grateful to hear another technique that can be a successful.

Should use a real desoldering tool. By that I mean the heater and the vacuum are the same device (not those cheap ass plastic "solder suckers)

You want to keep the tool on long enough to melt all the solder in the pad. Since the pins bias mechanically outward (from center of IC) I like to pull the pin in as I heat it up, and then suck the solder still holding it in. This prevents the pin from staying attached to the plated inside of the pad. Ideally you want a pin with a black hole around it. Grab it with your tweezers and move it back and forth to completely break it free. If it moves you're good to go!

Also one trick to desoldering is to actually add MORE solder first. Increases the mass and ensures all the nooks and crannies reflow. The older the device the more this helps.

What ruins traces is the glue bonding the copper to the FR4 failing. The issue I could foresee with your Williams boards is that the traces are thin to begin with, hence not much surface area for the glue to hold.

Also, heat transfer also works better if the surface is clean as possible BEFORE attempting to desolder. A fiberglass pen works pretty well for me.
Something like this --
https://www.amazon.com/Fiberglass-Sanding-Corrosion-Electrical-Autobody/dp/B07B7YSS76/ref=sr_1_2

Agreed. Oxidation, dirt, flux etc can prevent heat from transferring properly from the iron.

It can also prevent multimeters or logic probes from getting a good signal, so clean it / apply new shiny solder to avoid false negatives.

What is your preferred flux removal method?

I got my hakko back in February as a birthday present from my parents of all things. I don't know how I ever lived without it. I just finished a pretty heavy Taxi project with alot of board work and I can't even fathom the hours and mistakes it saved me from the old plastic solder sucker. If you do board work with any sort of regularity it really is the right tool for the job.

For sure. I was hesitant to spend the $$ for something I don't use everyday, but what a timesaver!!
Works best if you follow the directions & have the board setup @ a 90-degree angle when desoldering so you don't have to fight gravity & of course, use a brass wool tip cleaner on it to make sure the tip transfers the heat as it should.

I have to agree with what others have said. I was reluctant to buy a Hakko because I didn't think I would use it often and it was pricey.

The first time I used it I immediately wished I'd bought it years before and in the years since it has been a total time saver. A proper desoldering tool is the way to go.

I have used your method and it does work consistently. It is a very inexpensive way to desolder chips. It would be nice to be able to afford high dollar soldering equipment. If I have to do that, I will just send the board out for repair.

Nah, there are plenty of us cheap skates out here were just not so willing to admit it!

I repair boards semi-regularly and have used both methods. Personally, I prefer using a desoldering gun. It is just easier and simpler for me. I cut the IC legs with wire cutters first, then usually only have to hold the gun tip on the pad for two seconds before sucking everything out. Sometimes the legs get sucked up too - even easier. The solder sucker works just as well but takes longer in my experience.

There definitely isn't anything wrong with using this method especially if your only doing it maybe once a year. I sure is shit wouldn't get a de-soldering gun either. I stayed with the pump for a long time before I finally went with the gun for the same reasons. Its a lot of money, especially for a brand like PACE or something. I have to tell you though after using it the first time to take out an IC chip, I was like OMG where have you been all my life.

Think the other reason I finally said goodbye to the pump is because after X amount of de-solders the tip gets melted down enough to where you have to buy new ones or they break apart. finally went through a dozen or so of those plastic ones and then bit the bullet.

some boards are easier to work with then others, most are like this. The ones that aren't are the ones you risk damaging. I had an ASTRO (used for gambling games) board that pissed me off to no avail. I tried putting a coin cell battery in place of the super cap since it started leaking. Think that board is toast now . Gonna wait for a while before I look at it again. I still have one hole where the solder refused to come out, no matter what I did.

If you can't afford a desolder gun, at least get the proper tip for your iron.

weller-t0054174799-1 (resized).png

Vid can you tell me what that is called and its use thanks

And give yourself about a 3 hour warm up time

There is more easy way as other tells.
I never damaged boards when replaces ICs or whatever it is.
First use cutters like this to cut each leg from upside ofcourse.You did this with the dremel.
https://ae01.alicdn.com/kf/HTB1L4UoKXXXXXb4XpXXq6xXFXXXV/Budweiser-lion-5-inch-125MM-diagonal-pliers-electronic-wire-cutter-pliers-shear-pin-IC-pin-clamp.jpg

After that just put some solder on each leg and after that one buy one with the soldering gun and pincet remove them.
For clean the solder and to make nice holes use soldering pump and you are ready.
In most of the time I use 30W/40W soldering gun and never had problems.
For multilayer PCBs use my control temperature soldering station.

I have a desoldering gun, but my 0,8mm needle also works good without any damage:

I think it can depend honestly. My experience with the hand pump/suckers and other tools is that they are time consuming and (at least in my personal experience) are a lot more mistake and error prone. Honestly, knowing what I know now after having it, even if I only did board work a few times a year, it would be the best way to do it quick and most importantly right. I'm a believer now lol

Too bad finding a iron that can support these and buying the tip is usually more expensive than just buying a hakko desoldering gun.

IC Removal Tip

It heats up all the legs of an IC at the same time so it can be quickly extracted intact.

I've still got one from Radioshack that came with the iron and tip for $9.99

Ion makes a "double iron" . It's funny looking.

Weller sells the tips if you have a Weller station. There is a Weller guy at all the swap meets that has a bunch of different sizes for $11.99 each - more than I paid for the iron and tip back in the day, lol.

Similar to another comment, I generally clip the IC free with a good pair of pointy nose cutters. Bit less noisy (and messy) than the Dremel, and less likely to cause other damage if your hand slips!

The one thing that I do not think I have seen mentioned yet, (preparing for the incoming flames) and this is strictly a personal leaning... I never reinstall an IC in a board that I have had to remove one from without first installing a good quality, double-wipe IC socket. Just don't think it is worth the possibility of board damage if I have to go back and work on the board again.

Sure, you can say that once you have replaced a particular IC the odds are fairly low that you will have to change the same one again... (paging Mr. Murphy!) But especially these days with a lot of these chips becoming harder to come by, and the often questionable quality of the parts sourced through places like eBay, various overseas outfits, etc. I would just as rather not tempt fate.

YMMV

That's a good practice. If a chip fails once, it will fail again.

A great example is the amazingly cheap ZX Spectrum computer. Cost reduced and priced down to the BONE, but the ULA video chip was still socketed because it was the most likely to fail.

https://en.wikipedia.org/wiki/ZX_Spectrum

This seemed like a good place to post what I like to call a board repair skill level test.

WARNING: This level of board works requires a professional level of skill to accomplish and is not recommended for anyone without proper tools, training and experience working on these boards.

The task: Remove the WPC89 RAM IC chip intact and undamaged, install a chip socket in the original RAM position, install removed RAM in chip socket. MPU must be undamaged and operational with original chip in socket, AND board must look like it has never been worked on.

Original Board: pasted_image (resized).png

Board was Cleaned up to remove strange white "correction fluid?" material and old Bally labels; ST:TNG ROM was installed for testing.

Memory Removed: pasted_image (resized).png

Closeup: pasted_image (resized).png

Fully operational with original RAM in socket:pasted_image (resized).png

Nice Job!

NOPE!!! Not removing the ram on a WPC without snipping each chip leg. My first two attempts resulted with one or two pulled traces. Now I just snip away and no more problem. Guess my skill is a little under par but gets the job done.

We use Fluxoff or an equivalent at work. But for consumer goods, I'd be worried about damaging plastics. At home, good ol' IPA and a toothbrush. Doesn't work nearly as good ('good' as in 'how quickly') as Fluxoff, but it does eventually get the job done. Some fluxes are harder to remove than others.