[sdiy] help with uQ repair

[Julian Schmidt]

I checked the 3.3V supply and it delivers stable 3.3V
Xtal is running at 14.3MHz and the Clock IC is forwarding the clock to 
the DSP

I only worked with SHARC DSPs so far, but I guess the motorola DSP has 
no internal program memory and is bootet by the uC from flash and has 
its OS stored in the attached SRAM?

The rest of the PCB, especially around the DSPs looks pretty good. All 
sketchy looking parts where located to the left of the uC and the DSP is 
on its right side. Caps look good, too.

Here is a pic of the board.
http://chipmusik.de/dump/uQ.jpg

I'm a bit concerned that the firmware update does not seem to work, as I 
guess the DSP should not be involved with that.
Maybe an indication that it could be the flash indeed?

Any idea how to check the flash?

Julian

Am 23.02.2017 um 15:56 schrieb Christian Tecl:
> Hello list - hello Julian....
> I guess you already checked everything round that flip flop, 
> resistors, diodes etc... To me there are also reasons to suggest a 
> problem with power supply, maybe you check that also before soldering 
> that dsp... And think about the possibility that it could be the 
> flash, also. Like to hear what you are discovering. Greets Christian
> -- 
> Diese Nachricht wurde von meinem Android Mobiltelefon mit GMX Mail 
> gesendet.
> Am 23.02.2017, 15:24, Julian Schmidt <elfenjunge at gmx.net> schrieb:
>
>     I have a broken microQ in the workshop right now.
>     It arrived with a scrambled LCD that only showed garbage.
>
>     after opening it up I saw someone butcher the D-Flipflop (bend and
>     shorted pins)
>     after replacing it the unit boots again, waldorf welcome screen,
>     os2.2,
>     then preset name.
>
>     yay!
>
>     bad news is the unit immediately freezes. No buttons and encoders do
>     something. :(
>
>     I tried the firmware update but on reveiving the sysex data the power
>     button makes a quick flash, 4 or 5 vertical bars appear in the LCD and
>     then nothing happens. Pingpong chaselight on the Inst. 1-4 LEDs
>     and the
>     message "please play back dump" or something like that in the screen.
>
>     In factory test mode all buttons, LEDs and encoders work.
>     Audio out test does not work (silence on all outs)
>     and the DSP test fails.
>     it only shows:
>
>     1:----- 2:----- 3:sig!
>
>     and repeatedly flashes "DSP REBOOT" every second.
>
>     So my guess is that I have a broken DSP.
>
>     Is it worth it to try and replace the DSP? they are still in stock at
>     digikey.
>     But I am open for other ideas since I'm not keen on desoldering
>     the LQFP144.
>
>     Best,
>     Julian
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