That s shaped print on the board is a built in fuse that protects the 5 volt internal power supply chip. Yours looks like it to a hit but just not enough to blow it.
Take some nail polish and paint over it. it will help in the transfer of heat to the board if it decides to get warm again. I don't know what the current draw is though that "smoke and char" protector but if it did go totally bad you couldn't put a fuse in it's place anyway. There's no room in between the back of the board and the case. There are probably inline fuse links, but I've never checked it out.
I had my PCM re assembled just using ty wraps for 2 years. Just this passed summer when I went to power wash the bay, did I actually take it out and complete the repair. I caulked it with GE 50 yr warranty silicone caulking. The tabs on the case will break off if bent too many times. These tabs are the only mechanical means in which the board is being held into the case. (outside of the silicone caulking)
The board can be temporally installed back into the case and just ty wrapped together without the fear of it shorting out. You should have left enough of the potting compound surrounding the computer that it won't be able to short to the case even though it might seem unprotected.
If you put too much silicone on the back of the board you might not be able to close the PCM up. Just cover up all the components and pins, let it cure, then put a bead around the edges when you install the board into the case. Someone else re-installed the ty wraps back on the connectors just firmly enough to prevent the weight and movement of the wire harness from causing the problem again. You chose.
I would check for frayed wires leading from the sensors TPS, cam, crank, 02s and trans. It doesn't look like that in line fuse can take much more.
Personally find this an amazing and provocative and BRAVE thing to do and then take the trouble to post. Thank you so so much. The best and what I consider the cheapest (in the long run) PCM I can find which I believe in the warranty offered is close to five hundred dollars. So, one thing is that your writeup is causing me to keep my old PCM rather than core it to them and then I will be under no pressure but to take my time and fix it, maybe switch it back in and have one still waiting. Don't know if that's possible with the programming entailed. At any rate: THANK YOU.
Reading all the posts with people replacing the PCM multiple times in order to finally get one that works, drove me to find a fix.
If the remans still had the same problem, it was something that they weren't doing to correct the problem.
They are having a similar problem with the hemi engine. Maybe Jeep engineers should be members of this forum. There's alot of knowledgeable guys working these problems that are coming up with solutions.
Muy buena Informacion, busque una solucion asi por bastante tiempo !
me ayudo mucho y me ahorro bastante dinero, hice le procedimiento para reparar la pcm ó computadora como le decimos por aca y ya no tuve ningun problema con mi Laredo98
Saludos desde Monterrey, Mexico!
I am doing this repair at this very moment. Hoping for good results. Getting the board out of the case was spooky enough but getting that gel off the board was a royal pain that I dont think has been stressed enough. I had been an ET for 20 years and in all that time never had to remove this stuff. Potted parts were throwaways. QA would generally destroy anything they did expose. This goop is nasty. So far I really can't get the lands clean enough to where I feel comfortable that I will get a good solder bond. I'll keep at it tomorrow.
Anyway - Thank you JS97ZJ for posting this. I gave this Jeep to my son and then this happened. Kinda sucked in the timing but its been a good education for him in vehicle ownership and a mans need to figure things out and not give up because its hard.
Use small amounts of acetone and brush in one direction. Some one posted this previously and I didn't put this method in the write up. Good luck. Getting the board out and prepping is the hardest part of the fix.
I believe im going to try this also. One question...instead of using acetone and a brass brush...would it be possible to use a small butane torch to heat the gel and remove it from the are to make the repairs?