M Audio 2626 Schematic

[Jazz P Bass]

Got an M Audio 2626 that the LED's all come on at once.
Or not.
It is a random thing at power up.
I was hoping someone could post the schematic for it.
The LED's are controlled by a HC595 Coded IC.
I could just replace that but I am not getting a signal to the Codec (unless it is 'killing' the signal).

[doctor]

Got an M Audio 2626 that the LED's all come on at once.
Or not.
It is a random thing at power up.
I was hoping someone could post the schematic for it.
The LED's are controlled by a HC595 Coded IC.
I could just replace that but I am not getting a signal to the Codec (unless it is 'killing' the signal).

Service of the current M-Audio’s products is the real problem, because manufacturer does not send technical information
(service manuals/schematics) even to official distributors.

If the device works properly besides LEDs (if so, which I strongly doubt) resolder Flash ROM/RAM/CPU.

If it does not work at all, I can recommend to you only two basic examination: check power supply voltages (I do not remember exactly, but 3.3V, 5V for digitals and ± 5 /± 8 /±15V for analog op amps is the common place) and clock existing.

Good luck

[Jazz P Bass]

Thanks for reply.
I sent it back to the customer.
DNR.

[Enzo]

What is the thing?

With a name like 2626, I makes me think "mixer."

ANy time I see a mixer with all the peak lites on or something similar, it almost always is a loss of one power supply rail, typically the -15v rail. And while my experience with that symptom has been it coming up in mixers, if I see "all lights on" on most anything, the first check I make is the power supply for missing voltages.

And if it is intermittant, I still look to the power supply.

You may have bailed already, but keep it in mind for the future.

[Jazz P Bass]

Yes, indeed, it is a mixer.
Computer interface to access 'most all' of the functions.
My first thoughts where also 'power supply'.
That is why I took on something I never even heard of, let alone how to operate it.
The opamp power rails ckecked good. + & -15Vdc.
Stable, no ripple.
The 3.3 V rail checked good.
The only oddity is the led's coming on (or not).
As they are controlled by the Codec ic, that is my first suspect.
The unit is still here, though.
I think I will order the Codec & throw it in.
If the led's still come on, I am done.
Again

[Enzo]

Did they check good DURING the symptom?

[Jazz P Bass]

Yup.
It is immediate.
The Codec is definitely 'commanding' the led's on.
As to clocking, there is 'clock synchro check' function that the power on led is used.
If it blinks, there is a problem.
It holds steady on.
I ordered the Ic.
I will keep all posted.
Aside: This company has taken Customer Support to a different level.
At registration of the product, a 3 digit code is asigned. (don't lose it!)
With that code you are allowed through the phone menu to a human.
If you do not have a code, one can be purchased in their web store for $14.95.
I have talked to a few 'official service' shops.
Most refuse to do warranty work.
They are not privy to equipment schematics.

[Jazz P Bass]

Something doesn't make sense.
There are (4) codec ic's. The part# is AK4620.
The HA595 is the 3 state buffer that receives the info from the codec & drives the Led's.
There is one AK4620 per 2 inputs.
And one HA595 per 4 banks of Led's.
I have to look closer at the datasheets.

[Jazz P Bass]

Alright, I would like to end this post
The common I was seeing from the Codec was the clock.
So I traced back the LED function & it goes to a small microcontroller/ DSP board.
The micro commands another 3 state logic ic to turn the led's on or off.
The one microcontroller is blistering hot!
This unit is toast.(pun intended)