f1anatic

Hey folks. i would like - if possible - to get a definite answer with regards to the fate of my unit: Carnetix CNX-P1900 Dual Output 140 watt Regulator with the optional 5 V 3rd output. Like most other folks I would imagine, I had it wired at the battery, set up to cut power after some time (I think 15 min), powering a USB hub (5 V), a monitor (Xenarc) and the Car PC (a laptop in my case).

Basically the normal operation - from about April of last year to about January of this year was: I put the key in the ignition - I would know juice is flowing to the system as my Xenarc green light would blink. I have a Master button for the PC, I turn that on and we are booting. If I stopped say at gas station and I took my key off the ignition, the monitor would turn off. The moment I would put the key back in (within a short amount of time), the PC would resume right where it was - windows had not gone into hibernation, GPS still tracking etc.

A couple of months ago I noticed that my screen would not turn on right away or it would not turn on again at all. I would have to turn off the car, and turn it back on sometimes several times before my screen would resume. Which made me think it was the PSU or the screen. Obviously I could not diagnose the PC all that well since I still had a battery in there.

Over the week-end the system would fail completely. No more current to the screen. I decided to take the things apart (not before attempting to reset the PSU by removing power to it completely, checking fuses etc. Well it seems there is no 19V, no 12 V output (as in 0 V) while the auxiliary 5V is putting out just 1.26 V or so. The screen turns on beautifully when connected to 12V elsewhere from the car, the PC works as well when checked with its native wall-plug PSU. So definitely it is my PSU.

Question: is there anything else (any tests, any diagnosis) that I can still perform on it before I ...buy another one ? Any thoughts as to why it experienced a premature "death" or is that its life cycle ?

I am a little concerned that a 100 dollar item survived about 1 year under a normal work load. After counting the wattage, I was doing about 100 W so I was under the 140 rating. The PSU was mounted in the trunk approximately under the 3rd brake light - so in a well ventilated area...

Timely answers would be much appreciated. Thank you.

f1anatic

Anyone ? 21 views and ... not even a comment about how a n00b should search?

DarquePervert

Wow? 4 hours and only one bump?

Two things:
1 - Twenty-one views is not all that many.
2 - You're expecting the user with the answer to your question to log into these forums, read your post and respond in the timeframe you dictate. That's just plain arrogant. Show a little patience.

As for your issue, have you verified the voltage on the ACC line with the key OFF and the key in RUN using a multimeter? It should read 0v and ~12v, respectively.
How about the voltage on the 12v line? It should read ~12v regardless of the state the key is in.

If your voltages are correct, there may be an issue with the P1900 unit. I know there are newer firmwares for some units. That may or may not be what you need.

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f1anatic

Well we operate on different standards: on the car forums, a technical question is answered quickly - definitely NOT 4 hrs. Wednesday I am leaving for Minneapolis and I needed Navi. Oh wait, sort of needed cause I will log on here and ask for people to tell me where the North Star is. Between that and knowing that the Sun sets in the west I should be straight.

Reminds me of how helpful you were in your first reply to my other question on this PSU a year ago

So you find it arrogant that I wanted some quick answer. Well, should you ever buy a turbo Subaru, and if I am still visiting those boards, then it will be my pleasure to help you as soon as I read the topic, provided that I know something about it. And if I don't, at least I will reply directing you to the people who know the answer.


I have checked voltages the way you describe. As a matter of fact there is a red LED supposed to be lit or blink inside the unit which isn't. Obviously I checked whether I have voltage coming into the unit and there is something like 14.6 V coming from the battery. Output is zero on the 2 main outputs and 1.26 on the 5 V one. Looks to me that no firmware update will do anything about it. I was just looking for someone to confirm this based on experience or from reading about it before I spend 100 dollars on another unit and another 30 in overnight freight.

Nola111

F1anatic, this isn't a company's technical support forum, it's a user discussion forum. I'm assuming you bought the unit from the MP3Car store... the place to make tech support demands on that note would be support@mp3car.com or alternatively, the Carnetix forums. I'm sure plenty of people here who have used Carnetix products (including me) can help you as well, but telling people in here that they need to respond on your timeframe is a little crazy, don't you think? It's a user community that's here for everyone to help everyone as they can. I can promise you that no one of the 21 views of your original post were people who read it and then said to themselves "Well, I know the answer and can help him, but I just don't feel like responding right now."

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DarquePervert

You're setting standards of how quickly someone is supposed to respond to you on any internet forum?
You expect anyone and everyone who might know anything about your problem to not only visit these forums in the time frame you dictate (in this case a four hour window on a Monday morning), but to read your post and respond with the most helpful response possible?

I'm glad that on your other car forums you get answers more quickly. However, placing that expectation on any other technical forum (vehicular, electronical, or otherwise) is just plain silly.

Not everyone is required to operate on your time schedule and it's your folly to expect them to.



Yeah, and that response holds true to this day. I stand beyhind it 100%.


And I responded to you when I saw your post with as much help as I could, considering my limited experience with the P1900.
Sure I pointed out some basic truths that you obviously don't want to hear, but I also provided as much information as my experience allows.

See? We're both as helpful as we possibly can be in as timely a manner as we possibly can be.
The difference is that I place no expectations on how quickly I'm going to get assistance on any internet forum. You do, according to your previous statement.


That's something significant, I'd think.



I don't know what you're using as a basis for determing that a firmware update won't fix your problem.
Granted, I'm not claiming expertise and I also don't know that it will fix your problem. I merely posed it as a possibility.

In the troubleshooting process I'm of the opinion that one should exhaust all possible solutions before they junk parts in favor of replacing them. If your troubleshooting methodology differs from mine, than junk away.

Either way, good luck to you.

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