Remove and socket SE/30 CPU?

[vtgearhead]

I have acquired a Dove Marathon 030X/SE accelerator board. Apparently it's compatible with the SE/30, but expects to plug into the CPU socket. The SE/30 CPU is unfortunately soldered in place. What do folks think about my chances of removing the original CPU without damage to the board? I do have many years of bench experience and own a pre-heater rig along with a Hakko FR-301 vacuum desoldering tool. My thought was to place the motherboard upside down on the preheater and apply the Hakko to the bottom after it was up to temperature. That said, I would like to hear from those more experienced before diving in an potentially ruining the board.

The biggest question in my mind is what target temperature to use for the thermal soak before going at the CPU pins.

 

[This Does Not Compute]

I've removed a soldered-on CPU from an SE/30 with just the FR-301, it's totally doable. You can buy new sockets here:

128 pin 13x13 PGA Socket: Phoenix Enterprises -PE- Connectors IC Sockets Tools Cable Wire

PGA SOCKET 128 (13x13)128 pin PGA Socket MachinedGold Plated ContactsTin Plated TailsThrough Hole PCB MountScrew Machine .1"x.1" pitchPin Grid Array IC Sockets

www.peconnectors.com

 

[vtgearhead]

I've removed a soldered-on CPU from an SE/30 with just the FR-301, it's totally doable. You can buy new sockets here:

128 pin 13x13 PGA Socket: Phoenix Enterprises -PE- Connectors IC Sockets Tools Cable Wire

PGA SOCKET 128 (13x13)128 pin PGA Socket MachinedGold Plated ContactsTin Plated TailsThrough Hole PCB MountScrew Machine .1"x.1" pitchPin Grid Array IC Sockets

www.peconnectors.com

That's very good to hear! Do you recall the diameter of the nozzle you used? Heat setting? What concerns me the most is that sometimes you get a real stubborn pin that refuses to clear. With a chip or a socket I generally grab on with a pair of long nose pliers and wiggle the pin to break it loose. Pins on a 68030 don't wiggle, they tend to break off if stressed.

 

[Elemenoh]

Do you have a hot air station? I'd do a pass with the desolder gun then soak with hot air to get the stubborn joints to let go. You can then clear those joints more thoroughly with another pass of the gun, wick and/or solder needles. The preheater might help too, but shouldn't be necessary.

 

[vtgearhead]

I have a hot air station (Global Specialties Blackjack) so I can certainly try that.

 

[JDW]

Prior to getting a Hakko FR-301 desoldering gun, I paid @Kay K.M.Mods (a true professional!) to desolder my SE/30 CPU and install a socket. He did a fine job, but it's best if you refrain from using the desoldered CPU (black plastic top) in your socket in the future because there is a tiny bit of residual solder on each leg and that can wreak havoc on the female pins in your socket. The gold topped CPUs with gold pins (no solder on them) are what work best in CPU sockets. Meaning, you can install and remove them many times without damaging the socket. This is an important consideration because I have removed my CPU-socketed Daystar PowerCache several times and put back a gold-topped CPU in order to test things over the years.

BTW, I'd love to see a photo of your Dove Marathon 030X/SE accelerator!

 

[vtgearhead]

I had already thought about the pins, and definitely would not plug that chip into a socket afterwards. Here's a couple of photos of the Dove board:

 

[vtgearhead]

I've removed a soldered-on CPU from an SE/30 with just the FR-301, it's totally doable. You can buy new sockets here:

128 pin 13x13 PGA Socket: Phoenix Enterprises -PE- Connectors IC Sockets Tools Cable Wire

PGA SOCKET 128 (13x13)128 pin PGA Socket MachinedGold Plated ContactsTin Plated TailsThrough Hole PCB MountScrew Machine .1"x.1" pitchPin Grid Array IC Sockets

www.peconnectors.com

Thanks for the tip! Maybe it's just me, but I've found Phoenix Connectors a huge PITA to deal with. High shipping charges and very slow to get things out the door. I was able to find a couple of NOS sockets on eBay and hopefully they are as advertised.

 

[This Does Not Compute]

That's very good to hear! Do you recall the diameter of the nozzle you used? Heat setting? What concerns me the most is that sometimes you get a real stubborn pin that refuses to clear. With a chip or a socket I generally grab on with a pair of long nose pliers and wiggle the pin to break it loose. Pins on a 68030 don't wiggle, they tend to break off if stressed.

Pretty sure it was the stock 1mm nozzle, with the heat set around 4 (out of 5). I don't remember ending up with any particularly stubborn pins, so maybe I just got lucky!

 

[JDW]

...with the heat set around 4 (out of 5).

On the FR-301, Colin?

The reason I ask is because my FR-301 has only 4 dial settings...

So far, I've only dared to go as high as setting #2 because that is marked as being 400°C. However, I've never tried to desolder the CPU before, so it very well could require more heat, especially on pins that touch ground or power planes. I defer to you experts on that. And the fact you mentioned earlier about having done the job with only the FR-301 (no hot air station at all to warm the board) speaks well of the FR-301 too. In my experience, I've found it to be a fantastic tool. I waited too long to buy one only because of the high cost. It's really worth it if you use it at least once a month.

 

[vtgearhead]

Hakko recommends 3-4 as proper settings for a multi-layer board with power planes. I'm going to use the preheater and bring it to 100C before applying the FR-301. Belt + suspenders! Keeping my fingers crossed

 

[This Does Not Compute]

On the FR-301, Colin?

The reason I ask is because my FR-301 has only 4 dial settings...

I couldn't remember what it topped out at. Either way I had it set to something like 75-80% of maximum.