Deathtrap

[shoebox]

Did you have adhesion issues with the double sided tape with first heat sink? Why did you change up the heat sink?

[R-P]

The first heatsink had double sided tape but I think I bought them at least a decade before using it in the Volvo... So adhesion was lousy.

The unit is always under power, at least part of it, and when malfunctioning, e.g. the central locking doesn't work: clearly something that is always ON waiting for a radio frequency signal from your key.

So my first solution was to add a heatsink to something that always produces some heat and that malfunctions when surrounding air gets too hot. But I still left the metal shielding-box around the processor in place. So the heat-CAPACITY of the processor slightly increased and through the heatsink touching the metal-shielding-box, there will also have been a *slight* increase in heatexchange with the environment, but it was still basically a electrical heater in a tiny room: think sauna...
So what I did now is open the door to the sauna and even cut out a part of the sauna wall And I even put a fan sucking air past the 'saunaheater'.
So the sauna is no longer a sauna.

And I think there was also some debate as to which IC (processor? memory? 2nd processor?) caused the heat. The first heatsink only covered the biggest processor, the new one is attached (with copper shims*) to two or three IC's.

I was a little worried when I just got into the car an hour ago (>>25ºC outside), but there were no issues. (Again, knock on wood...)




* copper has even better heatconduction than aluminium, but it is way too pricey and heavy to use in heatsinks (bar some rediculously priced amplifiers)

[shoebox]

Please how were you able to cut out part of the wall or housing?

Is this what you are talking about the slits at bottom of housing: https://i.imgur.com/naTIM9C.jpg

[R-P]

First try:





After this failed, I left off this lid.



The slits under the metal (below pick) make sure it can actually suck air past the heatsink. Any airflow is better than no airflow, and with the slits, it may actually have a pretty decent airflow from the sides sucking it straight out into the footwell. Far from perfect, but the best I could to before drilling and filing into metal just millimeters from a failing PCB...

[shoebox]

What kind of drill did you use? You did a clean job with slits. This might be beyond my ability, worried i might damage something

[R-P]

The slits are there from the factory but do very, VERY little for airflow when the lid is in place. No way I could have made them myself so close to the PCB

Originally Posted by R-P

[snip]... Far from perfect, but the best I could to before drilling and filing into metal just millimeters from a failing PCB...

Maybe I should have said "short of drilling and filing into..." instead of "before". You might read the "before" as if I had actually done drilling and filing, but I didn't. As I doubt that would have had a positive outcome. The PCB is laquered, probably as a quite effective way of protecting it against moisture (the somewhat orange glow over all components in above pic (and not "pick"..., how can I make mistakes like that?????)). But soldering is now impossible unless you can *somehow* get the laquer off. So e.g. soldering the metal shielding-box from the PCB to make slots to improve airflow and then solder it back is nigh on imposssible for my (reasonably advanced) sodering skills.

[bob865349]

Originally Posted by R-P

Right now I am so furious, I just want to drive it into a lake and forget about the darn thing.

There's something wrong, but it affects the locks in such a way that the doors cannot be opened with the levers. So if we were to be in it while I drive it into a lake (...), we would die a horrible death because the doors will simply not open. (Remote control doesn't work, central locking doesn't work when manually opening the driver-door, which is the only door we can open, thanks to the key).

How can this be that some malfunctioning piece of electronics can prevent a mechanical opening of the door with the doorlever? In a supposedly safe car???



AAARRRGGGGHHHHHH

Oh, and the dash does not function (apart from a few lights), the accelleration is worse than ever, the indicators don't work and the automatic rearview mirror is in night-mode. All (different) fuses that are related to these malfunctions seem OK.


Edit: this is scary... when googling it I get a post by myself from 2013... It's 30 degrees C again, like last time...

This also claims it is communication issues, but no solution. I wouldn't call disconnecting the battery a 'solution'.

If no one has suggested it yet I suggest you contact Lukasz at Volvo Diagnostics tel 07977660678. I have a 2011 XC70 D5 which had lots of issues when we first bought it Lukasz has fixed all of them as they have cropped up, he is a very fair and honest individual and his work is top notch. recently had a starting issue whilst in France, Volvo Chartre said it needed a starter motor at 735€ but after fitting it it still wouldn't start so they put it back together with the old starter motor and I managed to get the car back to the UK and then to Lukasz, all that was wrong was the main fuse on the positive lead from the main battery had blown plus one other . Volvo Chartre didn't appear to know about that. If you look on this website you will see lots of times Lukasz has sorted out problems that non of the dealers can fix. I would highly recommend him.

[shoebox]

Thanks. OK that makes things more doable. I basically have two option, and a possible tweak to second option:

1. Your way which seems to be working with for you

2. Essentially same method but point of difference is using self-stick heatsinks

2A. Wiggle the metal box surrounding chips off (metal shield will be off regardless of doing this). messaged somebody on another forum who did this. I'm not sure if they got lucky doing this without consequence. Wonder your opinion regarding this.

I feel with my present ability self stick heatsink might be low risk option for me without screwing things up. If not effective you think I would have issues removing heatsink? I hope Im able to get adhesive tape off.

[shoebox]

Please how did you attach the fan to the case?

[R-P]

Have a look here. It should have all pics.

You can see there's a slide-out part (think "drawer") which features the PCB that needs the heatsink. There's a metal cover over the heatsink that I left off.
And there's a black plastic cover that I also left off. They all impede airflow.

The fan is mounted on the part that holds the slide-out part (think 'cabinet' that holds the 'drawer'). The mountingholes from the fan align with the holes in the cover (= part of the 'cabinet') over the 'drawer'. So with some slight filing, I could position the fan directly over the heatsink (once the 'drawer' is in place.)
Connecting them was with these bolts. (Probably M4, possibly M3).



The maximum diameter of the head is just slightly bigger than the holes in the cover (part of the 'cabinet') so they sit almost flush. I don't think I tapped any threads into the fan-mounting-holes, but I might have, since it is increadably easy since I got a set of these:


Screwing the bolts in place has to be done BEFORE the 'drawer' is in place, as the screwdriver is inserted through holes on the bottom of the 'cabinet'. So that was a fiddly job.



EDIT: just found some older pics about filing down the fan to make it fit and the screwdriver entering through the bottom of the 'cabinet'. And I added them to the link above.