VOGONS


First post, by jolurove

User metadata
Rank Newbie
Rank
Newbie

Hello. I recently got a Sound Canvas SC-88, and when I connect it to speakers I get a loud static sound. I tried different speakers, as well as the rear output RCA and the front Headphone jack. I opened it, to check if there were any blown up capacitors, but everything seems to be fine. Also I wasn't able to get it running with a computer. I tried with a midi cable connected to the game port of a Sound Blaster AWE32 and with a MPU-401 MIDI interface card.

Is it dead? Is there any hidden setting I'm not aware of?

Reply 1 of 7, by yawetaG

User metadata
Rank Oldbie
Rank
Oldbie

Did you try replacing the internal battery with a fresh one? A low battery can cause strange behaviour (including corrupted sounds) in these units.
Other things to check for are interference (may be something as simple as being connected to the same power outlet as your PC), but in some cases the only solution may be moving to a different room or even house (if it's interference from a cell phone tower, for example).

Also check whether it's not just the volume pot that's turned wide open - because if it's that, and by accident you are able to make it work, the very loud sound might damage something. You did try playing a MIDI file, right? Speakers left/right connected properly? MIDI switch on the back of the unit set properly? (just checking the obvious)

Reply 2 of 7, by jolurove

User metadata
Rank Newbie
Rank
Newbie
yawetaG wrote:

Did you try replacing the internal battery with a fresh one? A low battery can cause strange behaviour (including corrupted sounds) in these units.
Other things to check for are interference (may be something as simple as being connected to the same power outlet as your PC), but in some cases the only solution may be moving to a different room or even house (if it's interference from a cell phone tower, for example).

Also check whether it's not just the volume pot that's turned wide open - because if it's that, and by accident you are able to make it work, the very loud sound might damage something. You did try playing a MIDI file, right? Speakers left/right connected properly? MIDI switch on the back of the unit set properly? (just checking the obvious)

I removed the battery alltogether, I've read some posts that said it didn't affect games, and can even be beneficial, as the unit resets itself after each power on. I did meassure the voltage of the battery, and I got 3V. But I'll try a new battery.
I didn't even think that the plug could be an issue, I'll try that as well. One thing to note is, the unit is from Japan, where the voltage is 100V. I live in Spain and we have 240V here, I'm using a transformer that outputs 110V (actually 116V when meassured with a voltimeter), could that be an issue? The PSU was one of the first things I thought of, but I think that may be difficult to find a replacement. It has two 12V rails and two 5V rails.

I can turn the voume up and down with the knob.

I tried connecting it to 2 different PCs, one directly to a AWE32 through the joystick port and with a MIDI interface card. The unit doesn't react. I don't get anything on the screen. It only says "Piano" on the top.

I tried connecting speakers from the RCA output as well as the headphone jack in the front.

The MIDI switch is in the MIDI position, I tried the others as well just in case, with the same results.

The thing is, even when there's no MIDI input connection, I still get the same static sound.

Reply 3 of 7, by yawetaG

User metadata
Rank Oldbie
Rank
Oldbie
jolurove wrote:
yawetaG wrote:

Did you try replacing the internal battery with a fresh one? A low battery can cause strange behaviour (including corrupted sounds) in these units.
Other things to check for are interference (may be something as simple as being connected to the same power outlet as your PC), but in some cases the only solution may be moving to a different room or even house (if it's interference from a cell phone tower, for example).

Also check whether it's not just the volume pot that's turned wide open - because if it's that, and by accident you are able to make it work, the very loud sound might damage something. You did try playing a MIDI file, right? Speakers left/right connected properly? MIDI switch on the back of the unit set properly? (just checking the obvious)

I removed the battery alltogether, I've read some posts that said it didn't affect games, and can even be beneficial, as the unit resets itself after each power on. I did meassure the voltage of the battery, and I got 3V. But I'll try a new battery.

I'm not sure you can actually use the module without a battery. It won't remember any settings that way. Try have a look at the manual.

I didn't even think that the plug could be an issue, I'll try that as well. One thing to note is, the unit is from Japan, where the voltage is 100V. I live in Spain and we have 240V here, I'm using a transformer that outputs 110V (actually 116V when meassured with a voltimeter), could that be an issue? The PSU was one of the first things I thought of, but I think that may be difficult to find a replacement. It has two 12V rails and two 5V rails.

The default voltage for Japan is 100V and there are specific voltage convertors for that voltage, but it should be able to take 110V with not too many issues (except faster wear of the power supply).

I can turn the voume up and down with the knob.

I tried connecting it to 2 different PCs, one directly to a AWE32 through the joystick port and with a MIDI interface card. The unit doesn't react. I don't get anything on the screen. It only says "Piano" on the top.

Just connecting the module to a sound card won't make it produce sound, it needs to receive MIDI data to do so.
"Piano" means the first MIDI patch is selected, and if you were to connect a MIDI keyboard the piano sound would play if you press the keys. However, if a MIDI file is played on a computer the module should react to that. You have the MIDI cable's MIDI OUT connector connected to a MIDI IN port on the SC-88 (either MIDI IN A or MIDI IN B)? Be aware that on factory settings the front MIDI IN B port won't work...

I tried connecting speakers from the RCA output as well as the headphone jack in the front.

The thing is, even when there's no MIDI input connection, I still get the same static sound.

Okay, that's weird. Is that both with headphones and speakers? Was it listed as "working" in the auction?

Reply 4 of 7, by jolurove

User metadata
Rank Newbie
Rank
Newbie

I tried some games that have General Midi support. Doom, Descent and Warcraft 2.

It was listed as working, but it was from a japanese auction site, with google translator, and you know you can only get so far with that. The funny thin is, I bought two MT-32 whiche were listed as "junk" and they both work perfectly. Now I have 2 MT-32 and no MIDI module 🙁

Reply 5 of 7, by yawetaG

User metadata
Rank Oldbie
Rank
Oldbie

Have a look at the manual and find the section on resetting it to factory defaults ("Initialize"). It's fairly rare to buy something from Y! Auctions Japan and have it not work - much rarer than on Ebay (in my experience, I think I got burned exactly once on Y! Auctions and I've been buying stuff - not all audio-related - from there since about a decade).

Another thing...are the audio output connectors clean? You can carefully clean them with isopropyl alcohol and some synthetic swabs. Do this with the unit switched OFF and disconnected from AC power!!!

Finally, take off the cover and have a look at the capacitors. If those look fine, then I guess the only remaining option would be to take it to a repairman who is used to work with electronic music instruments.

Maybe still post some pictures of your setup and the internals of the module?

Reply 6 of 7, by jolurove

User metadata
Rank Newbie
Rank
Newbie
yawetaG wrote:

Finally, take off the cover and have a look at the capacitors.

This module actually has to PCBs. And in one of them there are 6 SMD caps. Two of them seem to have some leakage. I cleaned it with isopropyl alcohol and tried again, and the module now detects the signal coming from the computer. The static sound disapeared and was replaced by crackling noises, for a couple of minutes, then it came back. Still no music though.

I guess I have to replace those. But I cannot figure out their values.

Here are some photos of said capacitors.

https://goo.gl/photos/8EWphGwbbJEvx9BM8
https://goo.gl/photos/wMcQMWsEjv8j6mnEA
https://goo.gl/photos/sNAxmzXLDsNkCrqA8

And here's a video of the unit "functioning".

https://goo.gl/photos/XPXAqCsDLcN4e8sE9

Reply 7 of 7, by yawetaG

User metadata
Rank Oldbie
Rank
Oldbie
jolurove wrote:

It also looks like the PCB has some corrosion damage near the chip in the middle...(from being stored in a damp area?)

Unfortunately I can't help you with the values of the capacitors, I don't own a SC-88, only the smaller SC-88VL, which has the same functions but a different PCB.