VSEs been parked up in the workshop for a week or so. Got a lift there to inspect the revitalised radius arms only to find the car radio serenading me at full volume!
Wouldn't turn off at head unit. Ignition was in position 0.
Couldn't put charger on as battery was only showing 10v and the "smart" charger won't fire up when battery voltage is that low. Had no option but to pull the fuse then disconnect battery.
Both of these actions are a huge no-no with radio turned on as rumoured to fry head unit and DSP amp.
Now taking bets as to whether the audio system will be completely toast the next time I manage to get to the workshop. Any takers?
50p says you'll be ringing Marty for a new one.
I'll take that bet, but only because Marty's away at the moment and his DSP replacement unit project hasn't yet got to the stage where it works with Nav and the 17 speaker system :)
It'll go towards your boot badge. :-)
Sounds more like a head unit issue to me rather than the DSP amp end.
I'd be able to make a DSP replacement to drive the full speaker setup, if I had a look at the wiring in the vehicle to see where the extra speakers were fed from - RAVE doesn't show any addition wiring diagrams for the vehicles with additional speakers over the standard 'premium' spec.
Factory nav is an easier one to replicate - I'm pretty sure I have a solution for that, just haven't got around to wiring something up to try is - mainly as a) had no time, b) not yet had any demand, and c) I don't have a working nav drive to test it on (I could test it on a normal line level signal though for proof of concept).
I don't see why pulling the fuse and or battery would kill the head unit or the DSP.... The DSP amp is pretty much all solid state, and probably has an EEPROM on it somewhere - but it shouldn't be affected by power loss... likewise with the head unit... The only thing I've heard that you can kill by sudden power disconnection is the nav drive.
Now sitting at home, scratching my head wondering what went wrong.
Car has been dormant for a week or more. Unlocked, tailgate open, EAS delay relay out. Key out. Battery is an MF31 1000 and was in good charged condition.
Battery was down to 10.1v when I got to shop and radio was playing. Interior lights came on when I opened the door.
So- was it a fault in the head unit that turned on radio and DSP, thus draining the battery, or
Something else in the car drained the battery and as voltage dropped it reached a low point where radio/ DSP turned on
I want to go and tinker with the car- very frustrating to be grounded, as it'll be days before I can investigate further.
I found, by experience, that if the battery voltage is dropping while driving (due to not being charged) as well as the multitude of dash warnings that come up (gearbox fault, followed by ABS fault, followed by SRS fault, etc) the system starts to shut things down to conserve power. One of the first it shuts off is the radio.
I don't quite see the connection (!) with a radio that turns itself on and you can't turn off though
Do the Alpines have the functionality to let you turn them on with the ignition off? I haven't had one for such a long time I can't remember, if I even tried!
If not, then they should only come on when the accessory circuit is on, providing a switched 12v to the unit. At which point, you should be able to turn it on/off as much as you like. The fact you couldn't to me sounds like its just lost the plot a bit internally.
CTek chargers play nicely well below 12v I'm sure - I've revived some relatively buggered batteries with one. Not sure what charger you've got?
Yes, the Alpine units will let you turn them on and listen to the radio etc with the ignition off.
They'll only let you do it if the code has been put in and all that, and I think they have a timeout of 20mins to stop the battery from being flattened too far.
My main charger is a C Tec Sloth. Unfortunately it was over at the house- all I had was one of the LIDL cheapy smart chargers, which didn't like 10 volts. I've since got my mate to stick my C Tec on the battery and it's now happily charging.
The Alpines do have a 20 minute timeout Marty. All used to work quite happily, but I'll see what happens when I get back to working on the car.
Frustrating that I've got some customer work waiting and the VSE sitting there with boxes of shiny bits to go back on and all I can do at the moment is plan what to do.
Having finally managed to get back into the workshop, thought I'd close this one off.
The detent/ switch/ spring on the on-off-volume knob on the Alpine head unit has failed. As a result, the slightest movement of the car turns the radio on.
Still a mystery as to why it spontaneously failed (worked fine when I parked car in workshop), but an opportunity to tear into the guts of the head unit and replace whatever spring has popped out.
Interestingly, I've had a look at my spare (AKA broken) unit and that's very definitely crispy where that pot/ on-off switch is soldered into the PCB. Obviously a weak point in these Alpines. As this switch also powers up the DSP amp, I imagine there's quite a bit of current floating around in there.
Existing one isn't crispy there so I'm optimistic I can fix. Well, mildly optimistic anyway!
The on/off button is a soft momentary switch, and the output to the DSP amp to turn it on will just be a trigger. That crispyness just looks like flux residue more than temperature related marking.
Doesn't show well in the pic Sloth, but the solder's badly discoloured as well. I agree on the trigger bit, but something's caused that to get hot. Maybe someone's soldered in a new one in the past or attempted to resolder a dry joint?
New broken one doesn't show any of that discolouration in that area. Now in bits on the bench while I find a bulb for my magnifying light. Wonder why sometimes doing a job means you have to do a completely different one to facilitate it?!
Orangebean wrote:
Wonder why sometimes doing a job means you have to do a completely different one to facilitate it?!
I was JUST trying to post that :)
Spot on :)
The discolouration might be solder, but more than likely just crispy flux.
As someone who's had one apart and powered up on the bench before, I can tell you that there isn't next to no current running through there.
From memory, it's actually just a momentary connection to ground (it's either got a floating 5v or 12v on it which is then grounded when either the button is pressed or the knob is turned) which then wakes the unit up.
The DSP amp has a permanent power feed which is where it draws it's current from. The thin grey/black wire is just a 'wake up' line that the head unit puts 12V on when it powers up, to tell the rest of the system to power up too - but that wire isn't current carrying either.
However, if your volume knob/power button isn't working - then you'll probably have to swap that encoder out, as the spring action is internal to the encoder, rather than a separate switch/spring mechanism
Cheers Marty. I knew there had to be a technical name for the combined pot/ switch thing.
An encoder- now I know what I'm buggering around with
After a good blast with contact cleaner and clean air, the springing action is fine. It's hyper sensitive still though. The contacts are making/ breaking as soon as you touch it, rather than at the end of the push. Swapping out is next on the schedule.