SP-303 Error Message 8 - DSP Error (Help)

[NecrumSelect]

Hey SP heads,

I recently purchased a broken SP-303 for dirt cheap to fix up as a DIY project and hopefully use it alongside my 404. I've fixed up a few pieces of hardware and speakers in the past successfully, but still have alot to learn. I'm pretty stumped on this one as far as doing it myself goes. There isn't much out there on Reddit, Spforums, and Gearspace that's much help.

First things first, I've used the original AC adaptor it came with (ACB-240), my SP-404 AC Adapter (PSB-1U), and my mate's SP-303 AC adaptor (ACB-240) that he uses for his working 303.

When I power it on, it shows "8." on the display screen and the peak light stays on.

The SP-303 DR.SAMPLE Service Notes issued by RJA say:

E.8 - DSP error

(Solder and pattern defection around the DSP IC and EFFECT RAM IC. Solder and pattern defection between the DSPIC and CPU IC. Device defection of DSP IC or EFFECT RAM IC.)

Opened it up and all the IC components seem to be in good shape, though it looks like someone has taken this unit to be repaired in the past and made some workarounds for other components.

So far I've:

Tried multiple AC adaptors.

Taken off the metal guards for closer inspection.

Given it a good clean with some isopropyl alcohol.

Checked continuity with a multimeter.

Inspected the board for any corrosion and bad soldering.

Tried to initialize internal memory to no avail (no response from buttons)

Thanks for reading! Hopefully someone out there can drop some knowledge on this! any resources or known fixes would be much appreciated.

I'm located in New Zealand at the minute.

If I manage to get it sorted, I'll post up a guide for others in the future.

Peace.

Motherboard Images:
https://imgur.com/a/h2R3oRf

[Girru]

What about reloading the OS, if possible to do in its current state?

Get a magnifying glass on the joints and to look for bad traces? Might be a chip gone bad but try reflowing the solder around the apparently affected chips, if you're handy with an iron?

Might be useful...
http://www.nquabayre.com/wp-content/upl ... Manual.pdf

[Girru]

Looks like something leaked in there or it was kept somewhere damp (New Zealand!) for a long time and got a lot of moisture in it or summat? Probs some corrosion somewhere causing a short. Maybe try an ultrasonic bath clean, if you can find somewhere that does it?

[Girru]

spliffsoldier on here is selling a fixer-upper 303 - you could make a frankenstein one out of the two? See the Marketplace.