amlin423

Hi guys,
For the past month, my Alpine head unit is turning on and off itself when I first start the engine. It'll continue to turn on and off from anywhere to bewteen 1 minute to 10 minutes and then it'll finally just stay on and everything is fine. This only happens when the engine is on..if the engine is off (key position on ACC)....this will never happen...I also notice that it NEVER happens in the morning when i first start my car ....This setup was fine for the first nine months and all of a sudden this is happening...

I've measured the voltage from the battery as this is happening and notice no difference than when it's working properly. voltage is constant...no significant inc or dec...

This is my setup....Alpine CVA1006(HU), AlpineDVA5205(DVD), Macintosh amp, Mac EQ, Arc audio AMP, and a Bypass device for the DVD... the remote turn on for all the devices are connected to a relay and the power and gnd for everything is connected to their distribution block...Ignition is wired to one of the wires that was connected to the factory radio. I also have the factory battery....umm..i think that's probably enuf info

I am thinking this is probably the head unit's problem but i'd like to have a second or third or fourth opinion before concluding...Also, if it is...since I installed it myself..i don't have warranty right? Just wondering what my options are if in fact it's the HU's problem..

Thanks in advance
Andrew

BananaGS

Andrew,
Even if you install the unit yourself, just call the manufacture and tell them that it does not work correctly after 9months or something, leave the installation detail out. I dont think they will ask, even if they do, just tell them bestbuy did it, got no receipt, just the amp receipt hee hee

I would cut the headunit wiring out and re-install it from the begining, use a different power wire running from a good source, just to test it out.

I can't really tell you for sure, you had check the power/ground wires going into the head unit and make sure they are secure, then the problem is in the headunit. I would double check the wires first (could be a loose wire touching the unit when the car is running (ACC) or just a loose power wire to the unit, only happen when there is vibration of the engine. also if the headunit has a fuse, check it also, make sure it's secured

if it still happen, then you need somebody to look at the headunit.

good luck
Anh

Mean Gene

Andrew - Where have U located the brain for the 1006? I put my CVA-1005 brain on the right ( passenger's ) side of the transmission tunnel & occasionally ( if I have a passenger ), they'll put their foot right on it & the unit shuts down then powers right back up. If the unit worked fine for 9 months & then something's happening, I'm with Ahn - I'd look for some short or loose connection. With the engine running there's more vibration ( although not much in a Lexus! ) & this might explain why things R OK with the engine off. Just a thought.

amlin423

Thanks Anh,
I don't think anything is loose because once the "on and off" problem goes away, it stays fine ..it it were a loose problem...i would think it would happen rather sporadically....

i'll call up the manufacturer to see if they can figure anything out..

amlin423

Hi MG,
You must've posted while i was writing...anyhows..yeah..like what i said previously...If it's something loose....the problem would probably occur very radomly ....meaning ...if I hit a bump, it'll probably turn off the system...but once the unit stops the "on and off" act, it's fine...it has never abruptly just shut off itself....only when I turn of the engine and turn it back on will the problem occur again....

the very strange thing is that it never happens during the first thing in the morning when I drive to work but I will almost always (90%) see the problem occur when i go home from work....the only logic i can see from this is that my car is baking in the sun and somehow the heat is affecting something....

My "brain" is sandwiched behind the back seat and "X-shaped" metal braces you see when you take off the seats....I understand there is little or no ventilation there but since i'm not powering my speakers with the brain i figured it won't get all that hot....perhaps I'm wrong?

engin_ear

iTrader: (1)

Some thoughts:
You'd be surprised how hot some things can get when you remove nearly all of the ventilation. (I just mounted a satellite tuner in the same spot, but behind an MDF wall that I built. )

I'll bet that you've hit on the problem: temp. The unit may be thermally cycling, or worse, the junction temps of some of the ICs are getting so hot that something is functionally failing (this is quite possible if overheating). One thing you may want to do to test it (a bit radical though) is drive around with your rear seats removed (and the black rubbery plastic thing out of the way) to see if the problem goes away. (If you don't want to remove seats, maybe you can expose it from the trunk side.) That will also allow you to monitor how hot it gets when not enclosed. If it is getting pretty warm when not enclosed, you can safely bet that you are baking it when you seal it in that space.

I solved the ventilation problem by installing a really small, reasonably quiet 12V DC brushless mini fan from the "Shack". If you have no wall back there, you could still mount something on the partition to draw air out into the trunk area. Many electronic products are expected to be cooled by convection (as the air heats, it rises away, creating airflow), but if there is no pathway out, the accumulated heat makes things much worse.

Percy

It could be a combination of both heat and possibly, some bad solder connections within the unit itself. I've seen it happen with some heavy duty servers (computer servers) where the surface mounted component and the solder connection wasn't good. Looks like very small micro fractures on the solder. When you power it up first thing, it's fine. Then after about a couple of hours, it'll start to randomly fail. The same situation can be applied to the auto enviroment. Has anyone tried sticking a thermometer in the trunk of the car during a summer day? I'd be willing to bet that it gets upwards of 140 degrees F in there! (more than likely hotter)

Definitely try engin_ear's recommendation of a small "pancake" fan, or some other means of pushing some airflow through there.

IME, I find that surface mounted components are a bit more vulnerable to vibration and heat related problems. The "through hole" method seems to be a bit more rugged due to the overall solder area per pin and the size of the IC package for heat disapation. Not always possible to use through hole due to the large scale or very large scale integration with the IC's in automotive/nav products since they're geared with space saving surface mount in mind.

Percy

engin_ear

iTrader: (1)

Agreed on the surface-mount thing. Often, on large flatpack pinout chips, some of the solder is not properly reflowed, and a few of the joints are actually held in place because they are encased in flux (a slight push with a pointed tool will always reveal these), and that's the only thing holding them. Excess heat melts the flux, and/or vibration moves the joint, and voila! - intermittent.

Through-hole stuff is positively more reliable, everything's just bigger, but we don't want to remain in that stone age, do we... ;-)

amlin423

Thanks guys, i really appreciate the thoughts...I'll try the seat removal suggestion first and see if it's really caused by the heat accumulated. If it is...i really have to try to find a place to install a fan...
Thanks
Again

amlin423

Update guys......
I tried taking out the seats but I still see the problem...

I'm thinking the relay has something to do with this...
The relay I'm using is for turning on the various devices in my car...This is a 30AMP 12Volt Auto relay I bought at radio shack... It's a SPST relay and my connections are as follows

(85) to gnd
(30) to 12V power
(86) remote turn on from the head unit
(87) remote turn on all the other units in my system.

*****I drew out the relay diagram but it turned out illegible so I erased it....basically....I followed the instruction from rec.car.audio's FAQ so it can't be wrong....


I pulled out the (86) connection while it was turning on and off itself and immediately the head unit stays on (returns to normal and of course with no sound since the amps aren't turned on) ...
and once i plug it back in...the head unit turns off and on again...I immediately thought the relay was faulty and rushed out to replace it...To my surprise...the new relay also acted faulty...I can't figure it out...if it's really the problem with the kind of relay I'm using...why was it working for the past 9 months?

Does anyone have a suggestion?
Thanks

Percy

My best guess....

There's a small surface mount transistor inside the head unit that does all of the remote switching. Possibly, over the period of a few months, this little bugger started to go bad and can't supply enough current to turn on the relay.

How much current does the remote line carry from the head unit? Some carry only 0.1 amps while others can pump out 2 amps. It should say on the wire.

Percy

engin_ear

iTrader: (1)

Howdy, amlin423.
You may at this point want to pursue the following option, which in my opinion, is more expensive, but an extremely improved solution, and it may possibly save you from having to replace your head unit if the turn-on circuit is in fact the problem:
I used a solid-state relay, instead of the usual electro-mechanical one, because the Lexus factory head unit (Nakamichi) could not source enough current to energize the relay coil. Works like a charm, very smooth. The part I used is a Crydom DC60-S5. It can handle 5A for all of the remotes (total remote turn-on current). There is also a 7A version if you need more current, or a 3A version if you want to save a few bucks. (Most remote turn ons draw hundreds of milliamps, not amps, so you should have plenty to spare.) The part can be obtained via DigiKey, a very common electonics supplier, www.digikey.com. The "DigiKey" part number is CC1127-ND ($18.80). I also recommend the clear plastic cover, DigiKey part number CC1070-ND ($2.35). (You can even have them send it via overnight mail if you like.) The solid-state relay is a MOSFET device that requires MUCH less turn-on current than a conventional relay, since the turn-on lead from your head unit only needs to drive the gate of a FET instead of a relay coil. The conventional relay coil can also suffer from "back-EMF", which, if not properly protected against, can fry your turn-on circuit in your head unit when you shut down (hopefully this is not what is already happening). The solid-state relay turns on at about 3 VDC, so even if your remote output circuit is no longer getting up to 12V, it should still work. (You should check its output voltage with a voltmeter, with no load connected.)
Note that the Crydom relay is a bit larger than an automotive relay, at 1.8 x 2.3 inches, and maybe 3/4 inch high.

Percy

Great suggestion! I'll be sure to incorporate this information (with credit of course) in the revised version of "the book". I had originally drawn out the standard relay with a 1N4001 diode for PIV protection. The solid state version sounds MUCH nicer!

Percy

amlin423

Percy, I'll check it out when I take apart my back seat this afternoon...

engin-ear,
haven't heard those engineering terms in a while...luckily I was a very VERY studious EE student

I'd try out anything at this point (besides replacing the head unit)...got one question tho...

-Why is it that this problem only occurs when the engine is on? If the relay is really the problem, shouldn't it also occur when the engine is off (key is on ACC position)? The only thing the headunit and relay "sees" is the battery voltage and the ignition wire and the only thing I can see that a car with the engine running is affecting is that the voltage is slightly higher when the car is running.....(brief drop when engine is started)....Basically...my question is how the remote output circuit is affected by the fact the engine is on ...how does it "know"?

Also...you said you mounted a satellite tuner....is that for XM-radio...if so....how do you like it? I like to listen to talk radio a lot but it's always on AM and the Alpine tuner is quite crappy...

engin_ear

iTrader: (1)

Percy:

Thanks.
I have more info for you regarding placement of diodes for both standard relays and solid-state. Not enough time right now to spew this forth, but I'll reply later...

Jerry.