Monday, 2 May 2022

How to Repair Bent AMD CPU Pins With a Mechanical Pencil

For decades, bent pins have been one of the realities of buying, installing, and swapping CPUs, especially if you’ve stuck with AMD chips after Intel moved to LGA processors back in 2004. While there are undoubtedly a few lucky individuals blessed with steady hands, fast reflexes, and a merciful lack of pets known to walk across a table with less than perfect regard for its contents, the majority of longtime AMD enthusiasts have dealt with bent pins at one point or another.

“Hurrah! I love doing this,” said no one, ever.

One of the most common ways to fix bent pins is to use a narrow straight-edge like a credit card or a needle to manipulate the pins back into alignment. A loop of thread or dental floss can also sometimes be wrapped around a smashed-flat pin and used to lift it back off the package. But there’s another method for fixing AMD CPU pins. It’s a little less common than the two methods above, but it beats them both hands-down for speed and efficacy, especially if you have a large number of pins to fix. The only tool you’ll need is a mechanical pencil — albeit one with a particular kind of tip, detailed below:

Perturbed Pins

Editor’s Note: The method described here is not brand-new, and we aren’t claiming to have invented it, but it was new to me when Jess suggested it earlier this year. I then ran this idea past some enthusiast friends and fellow reviewers, and while a few people knew about this method of repairing AMD CPU pins, most did not. Out of all the methods I’ve used to fix bent pins over the past 20 years, this is one of my favorites. — Joel

Recently, we brought two AMD CPUs back from the dead using the method we’ll describe below. No pins were broken off, but the chips had a couple different kinds of “injuries.” A swathe of pins had been flattened in various directions, and some pins had their heads bent together. While a fine embroidery needle can lift pins up again, it just wasn’t enough control to straighten them out. Ideally, if we could get the pins straightened out enough, the socket would allow them to insert properly, with the last helpful micro-adjustments provided by the AM4 socket itself. Without intervention, these chips were dead Jim, dead, and we had nothing to lose.

While a needle also proved helpful, the instrument we used for these repairs was a 0.5mm Pentel GraphGear 1000. The outer diameter of its metal nib fits between adjacent CPU pins without pushing on them, while the inner diameter fits just about perfectly around an individual pin. This close fit lets you adjust the angle of the pins relative to the chip, without having to depend on having perfectly steady hands so that you don’t crimp the pin halfway along its length.

To attempt this repair, you will want a workspace that is flat, solid and stable. You’re also going to need lots of light, and a magnifying lens of some kind is also recommended. Be sure there’s no lead in the pencil before you begin. Handle the chip by the edges of its solid base, lay it flat to do the actual repairs, and err on the side of being gentle.

For CPU Pins Bent Flat

Carefully thread the end of the pencil over the bent pin, like an arm through a sleeve, so that the pin slides into the pencil’s empty nib. Gently shift the angle of the whole pencil, and the pin inside will come with it. Slowly, angle the pencil so that the tip rests flat on the pin’s solder joint, and the barrel of the pencil is perpendicular — perfectly upright — against the plane of the green PCB. It shouldn’t take much more force than handling tissue paper.

With the nib firmly against the PCB, rock the eraser end of the pencil a few times in a very small circular “joystick” motion about the perpendicular axis, to equalize bending in any other direction. Although the wire is very fine, the metal pins have a certain resistance to bending, which you should be able to feel through the pencil. Remove the pencil and check results; adjust your angle accordingly.

For pins with their heads bent together

When two pins are bent together, it’s tougher to straighten them out using the pencil trick. So, we prepared them beforehand by separating their heads with a needle; this got the heads far enough apart to straighten both pins using the mechanical pencil.

Lay the needle flat and slide it between the rows of pins, like so, where the “o” is the point of the needle viewed end-on, and the lines are the upward-facing pins: | | | | /o\ | | | | (If the needle doesn’t fit between the rows of pins, it’s too big, and you’ll need something smaller.)

Our test CPU, partially repaired. You can see there’s still some damage along the right-hand edge of pins.

Find the place where the pins catch the needle. Then, with a gentle upward sweeping motion, use the needle as a lever arm and your fingertip as a fulcrum to mechanically separate the pins whose heads are bent together. The motion may feel like an upward flick at the end, because of the bent pins’ resistance. It’s important to sweep straight upward, because if you angle to the side, you may bend other pins. It may take several repetitions of the same thread-and-lift motion to get the metal to “remember” the bend.

Lifting a pin back towards vertical.

Once the heads of the pins stay separated from one another, you can use the pencil to straighten the pin the rest of the way.

Will This Repair Work For Other CPUs? What Kind of Pencil Do You Need?

A repair like this should work on any AMD CPU that has pins, although with older models, you may need to use a pencil with a larger inner diameter to accommodate the larger pins from previous generations. We haven’t tried it, so we can’t recommend it, but the same mechanical pencil we used for these chips is also available in a standard 0.7mm. (Our first instinct was to use the standard Bic “clicky pencil,” but the outer diameter of its nib is too large.)

The chips we repaired were a Ryzen 9 5900X and an AMD A8-5600. This last CPU stood in as our model for the photos above. After the repairs, they were both confirmed to mount properly and booted and ran without incident. This was obviously more important for the 5900X, but we confirmed the 5600 still worked as well following some enthusiastic pin-bending for photographic purposes.

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