WTF is up with my Radio

sixspence · Post by **sixspence** » 17 Jul 2019, 22:03

Pardon the French, but I've been having issues with the HU-650 in my '07 XC-70.
For a while it would be playing fine and then would randomly start cycling through the functions ... CD, FM, AM, AUX... etc. and then just stop on one. Kinda like roulette or something.
Now it just stopped making sounds altogether. It appears to be working in every way, but no noise comes out of the speakers. The reverse alert beeping sound stopped too.
I already purchased a used replacement radio, but don't want to dig in to that project and then find out that it wasn't the radio after all.
Any suggestions on what the problem could be or what to do would be appreciated.

Post by **MoVolvos** » 17 Jul 2019, 22:14

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No system before or after that should make head-unit go psycho.

DrDan · Post by **DrDan** » 18 Jul 2019, 00:34

The fault of two seemingly unrelated functions kind of points to failure of the PCB (bad soldering joints?). Hard to trace and fix unless you're an expert, so swapping the head unit seems a reasonable strategy. Beware that you need a unit from the same model year if you want more than basic functionality. Steering wheel controls, "reverse beep", dimming of the backlight and more are implemented using the CAN bus and apparently they changed the protocol between model years. There's more info on head unit compatibility somewhere in the depths of this forum.

DrDan · Post by **DrDan** » 18 Jul 2019, 01:27

Also an important bit: disconnect the battery before removing the radio. If you don't, an SRS code will be triggered. Set ignition to II before reconnecting.

sixspence · Post by **sixspence** » 30 Jul 2019, 15:21

Followup...
I replaced my HU-650 with another that I purchased off ebay.
The radio now works. HOWEVER... my Reverse Sensors are not. That may be an entirely separate issue, but it is VERY suspicious that the sensors stopped working at the same time my radio stopped working. It is throwing a message that the Reverse Sensors need attention.
Also... There is NO AUX on the new radio!
I used the AUX function all the time and now it doesn't exist. It may be possible that the HU-650 I installed is an older model than the original. Is there a way to enable/disable the AUX function?

Post by **MoVolvos** » 30 Jul 2019, 19:51

sixspence wrote: ↑30 Jul 2019, 15:21 Followup...
Also... There is NO AUX on the new radio!
I used the AUX function all the time and now it doesn't exist. It may be possible that the HU-650 I installed is an older model than the original. Is there a way to enable/disable the AUX function?

Where was the AUX originally? A quick look shows no AUX front or back on the HU-650.
https://duckduckgo.com/?q=hu-650+audio+ ... efault.jpg

Post by **MoVolvos** » 30 Jul 2019, 19:54

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"The AUX input is located inside of the center console..."
http://www.volvoxc.com/forums/showthrea ... -in-HU-650

sixspence · Post by **sixspence** » 30 Jul 2019, 20:10

Maybe I wasn't clear...
On my old HU-650, there was an AUX source input, along with FM1, FM2, FM3, CD, Serius XM, etc...
On my new (used) HU-650, AUX does not show up with all the other Sources.
I reinstalled all the harnesses and cables into the identical slots that they came from. I'm not sure which one was the AUX cable, but it shouldn't matter.
I'm wondering if there is a way to enable the AUX source on the newly installed head unit.

Post by **MoVolvos** » 30 Jul 2019, 21:23

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My understanding of an AUX input meant
1) It's a built in feature so it appears in the display along with FM1, FM2 etc.
2) In order to connect to an AUX source there is either a hole for the AUX source to plug into in the face plate of the HU or another wire/plug you can connect to with your AUX source coming from the dash.

As for getting the feature in a HU-650 there is a hack but I think many of us myself included probably can't hack it.
https://gizmosnack.blogspot.com/2015/11 ... radio.html

Post by **MoVolvos** » 30 Jul 2019, 21:27

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https://forums.swedespeed.com/showthrea ... r-champ-s)