Please Help: (M-Audio Axiom25 Midi Controller) Power Problem

[o0Roman]

Any help will be greatly appreciated. At my disposal I have beginners-mid level knowledge of electronics. Equipment: Multi-meter and other electronic related equipment

Unit: M-Audio Axiom 25 Midi Controller


Problem: The unit powers itself through either 2 sources, USB or 12V DC Adaptor

When powered on the unit usually will be stable and fully functional for a variable time.

In random times the unit seems to lose power and restart repeating this process several random times, until what appears to get back to fully functional. The LCD panel at this time flashes in a irradic manner like its losing power and trying to restabilize.

This is my starting point I have tried to open the unit and test several of the capacitors.

A better direction will help me a lot. I can provide digital pictures of the circuitboard and underlying components.

[vtech]

Not familiar with the unit but based on your description, it may be anything from a bad connection or power supply/regulator problem. Rather than jumping for capacitors or any component for that matter, you should try to determine and come up with some diagnosis as to what is going on;
Is it a connection issue? Is it a thermal issue or even a control issue?
Does it happen with both USB and adapter as a source? Can you replicate the problem by heating/cooling on the pcb.
You can try doing some random Dc level checks at various spots or better yet while it is acting up.
Have you tried contacting the manufacturer for any possible info or software upgrades? ---too many variables involved here.

[o0Roman]

Thank you vtech for your help

This is my diagnosis so far:

Power Diagnosis
It is not a connection problem as I've tried USB by itself and DC power by itself. Both exhibit the same reaction.

It power the unit up and at random intervals looks like it loses power and then gains it back repeats several time and then stabalized for periods of 10-50 mins. Strangely this happens around first 4 minutes of power up then doesnt do it for 10-50 minutes even when using the unit.


Thermal Issue

I have not tested if heating or cooling the pcb can replicate this reaction.
I will use a hair dryer to heat the pcb and monitor the temperature with a thermometer and watch the reaction. Is there any specified critical temepratures that I should be aware of?

Connections Issue

I will check the DC levels at various spots before and after its acting up. What points on the PCB should I inspect? connections between capacitors? connections between resistors? connections between solder points?

Driver/Software Issue

This unit is plug and play, I have updated all the drivers and software and it does not have any firmware. The manufacturer does not give information although I have a hinch that this has happened to people before rather they insist on mailing it to them having them fix it and paying for labor, parts and shipping.

Final Diagnostic thoughts: It is either a power connection issue, thermal issue, or faulty connections issue.

I can post a picture of the PCB as this might help

Thanks vtech and anyone that wants to input[/b]

[vtech]

As far as the heating, there is no set rules. The main idea is to use heat as tool to possibly induce the problem--may or may not work. Also, for measuring DC levels, you would want to try main supply line(s) such as 5volt plus/minus 12 v etc. Again there is no set rules per se.
Now as a general rule, if you can time the problem on a pretty much constant basis, it may in fact be a software or compatibility issue they prefer to keep hush unless there is enough complaints.
I've always hated outfits who decide to keep it to their own for whatever reason. all you can do is to try the basics and hope for the best.