Im making a tutorial for the Roadrunner guts kit install today.

[wait4me]

Just as the title says. Im making a detailed roadrunner guts kit install for you guys. It will have pictures and maybe even video if i get bored enough..

[hquick]

Good idea Jesse.
I don't understand why Craig doesn't have any info whatsoever for the 'guts kit' installation.

[N0DIH]

I was a little surprised too. But not for someone who is not familiar with soldering these parts. Once off not too bad, but taking off the TSOP44's without damaging the PCB can be another story. A good install guide would be excellent to have. I have done 4 installs so far.

PLEASE guys, this is important. Bake the PCM first, around 180F for 24 hours prior to trying to desolder parts. If the PCM sits for more than 30 days, you will need to bake again. I work in the industry, this is VERY important. VERY, I cannot stress it enough!

You can tell me up and down how it hasn't caused a problem. Trust me, it does. I worked in automotive telematics at a PCM manufacturer for a 5 years and still work in the industry.

[hquick]

Wow! Never knew that Tom. Why?

[N0DIH]

Quality is a big concern. And it prevents delamination of the IC's and PCB. Basically the moisture will boil violently when you heat up the PCB with the heat gun.

Sometimes when you try to yank a part off you can literally pull the part apart in pieces. And the other parts on the board that got warm (all of them, these pcb's are 2oz copper and heat goes EVERYWHERE) but not messed with now have the moisture not completely evaporated and it will cause internal IC corrosion problems. So now the PCM is likely going to fail soon, it is only a matter of time.

Being the parts are NOT hermetically sealed packages, they all can get moisture in them, you have to "cook" it out, the PCM's that have the plastic gook on them covering the parts are much more tolerant than the ones that don't. At least it isn't like Dodge did where they pot the whole thing with that rubber stuff....

So it is by far best to do so. Will it work without? Sure, but you are setting up for a problem down the road. Granted, PCM's are relatively cheap, so you just yank your header back off and put on another. All up to the user.

You know, come to think of it, some PCM's that reside underhood might really get baked on a daily basis. In retrospect, might not be a big deal at all. Hmm..... My LT1 PCM never really gets warm, but the Gen III truck PCM's sure do as well as my black box PCM in my Vortec 454. So it might be application specific whether or not you need to....

I have seen some put the PCM in the airbox so it will stay cool, some underhood, some behind headlights, some next to exhaust manifolds, etc. The are all over the place as most know. So if you know that your PCM regularly gets 180+, then I don't think I would worry about it. It isn't so much reusing the old part (you can, just bake it first or keep in dry pack somehow with humidity detecting stuff, I can probably get lots of from work that we toss often once opened if anyone wants some) but the parts around it could get damaged.

It is an automotive requirement to bake parts, doesn't matter if on or off PCB's, if they are going to be removed, or placed, and they haven't been baked for 24 hours based on the MSL level of the part (how long they can go without baking) then the need to be. It won't hurt the part. IC's are almost ALWAYS MSL3, Moisture Sensitivity Level 3, which is 168 hours out of dry pack before baking is required.

More reading on it:
http://en.wikipedia.org/wiki/Moisture_Sensitivity_Level
http://www.siliconfareast.com/msl.htm


Wow! Never knew that Tom. Why?

[hquick]

Thanks for the explanation Tom. Always nice to learn something new.
I'm an electrician by trade but have limited electronics experience.
The old 98 PCM had the rubber coating you speak of.

[wait4me]

With the right stuff you can pull off a chip in 5 seconds literally. No need to heat the computer in the oven.....

[N0DIH]

Only if you are putting the heat on the pins only. If you have that equipment to do, by all means, do. Very few do, engineering rarely has, factories do, as they need that sort of equipment. By now you probably can get them reasonable.