[Android Head-Units] kaween:
No. What you're describing is thermal damage. A fan alone won't help.

Allow me to explain :

The fan is really just a stop-gap and sits at the wrong position to make a real impact. To get your ARM to cool, you must modify the unit with the cooling block as I described. Reason : the ARM sits at the underside of the motherboard, facing the bottom of the unit's housing. The fan actually sits on the topside of the board, and there's very little spacing between the MCU board and the rest of the housing, so there's really very little airflow. The fan is an exhaust fan by the way, so it pulls air out of the unit at the back and tries to suck it in from all the other small holes in the housing. The fact its airflow is obscured by the DVD-playback unit doesn't do it any favours either by the way.

Hence the best idea I was able to come up with was connect a cooling block to the ARM, and let the cooling block make physical contact with the bottom of the unit. That way, heat transfer from ARM to Cooling block, and from cooling block to rest of the body (it actually uses the complete metal part as cooling that way, and so benefits from the fan in the end.

As said, I used a Scythe 4x4cm fan which I has lying around, sp0410fdb12L. The cooling block was something I nicked of a defective VGA board. There's no way to physically secure the cooling block to the ARM board, so I chose a cooling block that was just the correct height to press-fit between the spacing between the ARM chip and the bottom plate of the unit. It is 13mm high, and cut to a rectangle of approx 2x4 cm. Put some cooling paste on the arm, stick the cooling block on it, MAKE SURE the cooling block is flush with the ARM as there are a couple of capacitors that are a tad higher than the ARM is : Make sure the cooling block avoids them to make full surface contact with the ARM. Remember, this is meant to be functional, not pretty. :)

Look where the cooling block resides when your mount the pcb back in place and secure it with heat-resistive aluminum tape so you don't risk it coming loose at some point. Do NOT put any tape or whatever OVER the cooling block, as it must have metal-to-metal contact with the bottom plate .

Anyhow, if your board is behaving like it does now, you could reside yourself to try and do a reflow of the ARM. Just making the cooling better now is, I fear, too little too late. The cooling mod is there to avoid a repetition of the issue.

You said you were no stranger to tinkering with repairs and hardware. In that case I would try this :

Make sure you can do some testing outside of the car. Get a stable 12V power supply and make sure you can connect ACC, BAT and GND. It beats trying to do this stuff while sitting in your car. :)

1) first get your unit out and see what the fan does. It should run, even when the board is crashed. If it doesn't, you either have it shut off in the settings menu OR put i to a "low" higher setting which prevents the fan from starting as the treshhold temperature isn't achieved. Of course, if thermal damage has occured, that treshhold isn't of any value anymore.

2) if the fan runs (try to cool the unit down before you start, when started, go to the settings menu and check out the settings Mike filmed for you) you know that at least. If not ... new fan.

3) go on the lookout for a cooling body with the provided height. Get some coolpaste. Try mounting the cooling block and coolpaste, mount the unit back together. See if it remains stable. I give you less than 10% chance, but everybody's allowed to have a lucky break at some point so you have nothing to loose anyway.

4) not running or still unstable ? Try a reflow of the ARM chip (you CAN NOT MISS it, it's the only silverish chip on the board, and it clearly states "MS789" on it, and it's about biggest chip on the board.)

If you do not have a relfow station or don't know somebody who has, I wouldn't really think you've got much chance of getting this to work. There are some people who've had succes with a paintstripper gun blasting the chip for a minute in a circular motion .... but I won't condone nor promote that kind of "Macguiver" solutions.

If it comes that far and you lack the correct tools, better search for some electronics shop who can do a simple reflow for you. Any shop that repairs PS3's and Xbox machines will be equiped to do this.

5) still nothing ? New board. Will still be a lot cheaper than a new unit and unless you're not content with the AN21, I do think it's worth it.

Cripes. I blabber too much. :silly:

Good luck, and keep us posted.