Let's Get Naked - De-Casing the PII

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Let me put up some disclaimers up front: What I am describing here is how I took the case off a PII 300. I am very experienced with power tools and precision measurements and as such employing this methodology presumes such capabilities. Even so, Overclockers.com and its contributors assume no liability for the consequences of any person’s actions using any techniques described herein. Note also that this does not apply to the newer case design of some PIIs (the SECC2 Case) like the PII 400 SL3EE.

With that out of the way, the first time I removed the case from a PII, it was a struggle! If you read any of the articles about this, they all tell you how difficult it is to take off the last pin. There’s a good reason; if you look inside the PII case, you will see 4 sockets into which the 4 pins of the PII thermal plate fit. The socket in the lower left hand corner is round, while the other three sockets are oval shaped. It would appear that the round socket is something like an index socket, one which orients the other three pins. So there is no play in the index pin, and a lot of play in the other three – that is why it is relatively easy to take off three of the four pins.

Now I don’t care what you read, it is damn hard to get this last pin off. I mean I have seen cases that look like someone took a sledgehammer to it! Thinking there has to be a better way, I looked at the back of the plastic case and decided to use it as a template to drill holes in the PII case’s plastic back I was removing. The case is about 1/16 inch thick, so any drilling to be done would not exceed 1/16 inch depth; if I missed, no harm done except a hole in the case. I used a 1/16 inch drill, figuring the hole did not have to be huge, just enough to find the top of the metal pin attached to the thermal plate.

To make a long story short, I placed the old, empty PII case over the one I was wanted to remove and drilled very carefully. As I contacted each pin, the plastic case popped up. The last pin, the round one, did not, so I used a product called “Liquid Wrench.” This is a penetrating oil that is used to loosen up frozen nuts – all you need is maybe ½ drop into the hole drilled in the lower left hand corner, wait 15 minutes or so, and with very little coaxing with a thin-bladed screwdriver, it popped off. I literally could get the other three corners off by hand.

The second step is taking off the retaining clips which hold the thermal plate to the CPU’s PCB. I read a lot about using a small screwdriver, carefully bending back the tab on the clip, etc. It’s all BS. I found the easiest and simplest way to remove this is to use a needle nosed pliers, grasp one end of the clip and twist it up and off. If for some reason you want to reinstall the clip, straighten it out and you can reassemble everything – the only thing you will see are the four holes in the back of the plastic case. However, that was not my objective – I wanted to open it up for better cooling and to see what speed the cache chips are (5 ns)…I always wanted to know that.

The diagram below gives the measurements I used. This is not a scale drawing so don’t think of using this as a template. The most critical measurement is the lower left hand hole – if you start with that one, then you measure off the upper hole from it. The measurements for the lower holes are taken from the raised plastic edge on the back of the plastic case. I am just showing one side, but the other side is exactly the same. Once you contact the metal pin through the first hole, everything else falls into place.

PII Case Diagram

Now I will say it again – it works for me without serious trauma to the case or me. I can get a PII totally naked in 10 minutes. Whether or not it can work for you is for you alone to determine.


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