VOGONS


Reply 301 of 335, by Oetker

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jbeougher7924 wrote on 2022-01-22, 14:35:

I just purchased my first SC 55/first midi device. The seller said it might need a new battery. When I opened the case there was no battery. Easy fix and now I have a fresh coin battery in my SC 55. Still no midi sound yet except for the demo ROM songs. Not sure what is causing that.

If you're using a db15 midi cable, it might be a bad one.

Reply 302 of 335, by jbeougher7924

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I am using a Roland UM 1. I have plugged the UM1 OUT -> SC55 MIDI IN1 and MIDI IN2. No go for either. The UM1 OUT led is flashing and when I start dosbox it list the UM 1. I have changed the midiconfig=1 which is what mixer /listmidi showed as the UM 1 device number. I am running win10 with Dosbox v74. I know the line out is working since I can hear the demo songs through my speakers. However when the UM 1 device is showing active out the SC55 show no activity on the display. I have also done a factory reset on the device.

UPDATE:
The SC55 is fine. I used the built in factory test and confirmed that all midi ports work. The problem was the UM1. I am now using a mio XC and it works. I was amzed how well master's of magic sounds. DB build in MT32 emulation sounds okay after listening to it through the SC55. Just wow.

Last edited by jbeougher7924 on 2022-01-22, 22:33. Edited 1 time in total.

Reply 305 of 335, by Shcookius

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Hello, I have a SC88VL with some residue near a capacitor next to the VRM heatsink. While the red stuff is expected the white powder isnt. Somewhat worrying. Pictures here:

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Reply 306 of 335, by Pierre32

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Shcookius wrote on 2022-02-11, 23:38:
Hello, I have a SC88VL with some residue near a capacitor next to the VRM heatsink. While the red stuff is expected the white po […]
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Hello, I have a SC88VL with some residue near a capacitor next to the VRM heatsink. While the red stuff is expected the white powder isnt. Somewhat worrying. Pictures here:
0211221531a.jpg
0211221530_HDR.jpg
0211221529.jpg

Might be similar to this: PCB destroying adhesive found in my Roland Sound Canvas SC-55mkII (inspect your synthesizer!)

Reply 307 of 335, by Kahenraz

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That's exactly what I found in my SC-55mkII. A dark brown adhesive that has decayed into a dry, hard substance that has chemically reacted to corrode the copper ground plane of the PCB and any nearby traces.

The capacitor will need to be removed and the surrounding area purged of the damaging corrosion, neutralized, and missing traces repaired. It looks very mild on the surface but there is serious damage hidden beneath the green solder mask.

In my unit they used the same brown adhesive to also tack down bodge wires. You should check to see if there is corrosion elsewhere as well.

Reply 308 of 335, by Shcookius

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Kahenraz wrote on 2022-02-12, 00:12:

That's exactly what I found in my SC-55mkII. A dark brown adhesive that can be identified as a dry, hard substance that has chemically reacted to corrode the copper ground plane of the PCB and any nearby traces.

The capacitor will need to be removed and the surrounding area purged of the damaging corrosion, neutralized, and missing traces repaired. It looks very mild on the surface but there is serious damage hidden beneath the green solder mask.

In my unit they used the same brown adhesive to also tack down bodge wires. You should check to see if there is corrosion elsewhere as well.

Oh no.

Just a few minutes ago I took some rubbing alcohol and removed some of that white stuff, noticing that the tip of the Qtip was green from the solder mask.

And the close proximity of that capacitor to that damn heatsink as well makes sense.

Panic time.

Hopefully, being such a late model (88VL) that stuff hasnt had time to do much damage, but it sure looks bad on the surface sooooo...

Thanks for the warning. I will look at it more here shortly. 😦

Reply 309 of 335, by Kahenraz

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There will probably be corrosion beneath the capacitor as well, as to was on mine. You'll need to remove all of the contaminated material with a fine but bluntly tipped instrument. The corroded surface should crumble under pressure like a brittle crust. You'll know that you've reached the edge of it once the solder mask adheres strongly and scraping at it becomes difficult and reveals only copper.

Try not to dig too deeply looking for copper. If it's just brown under the solder mask then the copper has already dissolved. If it's just a brown surface this is probably Bakelite or whatever PCB material was used; on my SC-55mkII is was decidedly brown.

Once you've removed as much of the infected debris as possible, treat the area with vinegar and then wash it with alcohol. Only then will you be able to assess the true extent of the damage. In my case, for example, I could see what used to be traces as outlined by the solder mask but digging with my probe revealed only a hollow trench where the copper had completely dissolved.

I can at the very least offer you words of encouragement that this can definitely be repaired. The damage is very localized and there are only a few traces nearby, all of which can be easily bodged.

Reply 310 of 335, by eightbit

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Well, I have an SC-50 (which I love!) that I purchased for a song not too long ago and knowing already about this battery situation I immediately opened it and removed the battery when I had received it. Thankfully no leakage however the battery did look a bit cruddy. I suspect that it would not be long before it did leak as the battery had all of the green signs around the edges.

I removed it and didn't bother replacing it because I like the fact that I can bring the settings back to stock by simply removing power. I use this primarily for general midi in DOS games and it does not disappoint!

Reply 311 of 335, by Kahenraz

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I haven't heard of anyone else with this problem, but my SC-55mkII needs to have a battery installed or the pitch will be off. This is also the same unit that I had repaired in this thread so it's possible that something has become damaged for it to be in this state.

The Roland Sound Canvas SC-55mkII may be out of tune when powered on without a battery

Reply 312 of 335, by Dimitris1980

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This is definitely a very important topic. Thanx to this i have replaced the battery on my SC55, SC88 and Yamaha MU50.

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- Roland MT32, CM64, CM500, SC55, SC88, Yamaha MU50

Reply 313 of 335, by eightbit

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Bottom line, get the battery out. First thing I did when I acquired my SC-50. And it was starting to leak as well. Thankfully the damage was localized to just the battery and not the surroundings. I never put another battery in as I am not concerned about saving settings. As a matter of fact, I find it better to be able to unplug and re-plug the unit to get back to stock settings when I want to. And, I don't ever like the uneasy feeling of a battery being inside that I may forget about someday down the road.

Best solution for me is no battery at all!

Reply 314 of 335, by eightbit

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Kahenraz wrote on 2022-03-13, 06:33:

I haven't heard of anyone else with this problem, but my SC-55mkII needs to have a battery installed or the pitch will be off. This is also the same unit that I had repaired in this thread so it's possible that something has become damaged for it to be in this state.

The Roland Sound Canvas SC-55mkII may be out of tune when powered on without a battery

Definitely something is wrong if you need a battery installed for it to function normally. That in itself is NOT normal. I listened to your examples and that is just plain weird. Maybe yours without battery is an SC-54MKII 😀

And, those bodge wires aren't factory. Someone has been inside there playing around. Poor Roland...

Reply 315 of 335, by Kahenraz

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My SC-55mkII has firmware revision 1.00 so the bodge wires and other quirks may be a result of bugs from the first release. Unfortunately, I have no other units for comparison.

Due to the damage to the traces in the back, I have no way to know if this is a result of that or something common to these early boards. I'm certain that I repaired all of the damage, but it was extensive and it's possible that I missed something.

Reply 316 of 335, by eightbit

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I have a Yamaha TG300 coming. I saw a video and it appears that internal battery is soldered to the mainboard.

On my SC-50 which thankfully had a battery holder, I simply took the battery out and kept it out since I have no use of retaining settings. Will it work the same way on the TG300 if I desolder the battery and leave it out? Will the unit function fine other than a low battery message?

If anyone has one of these units and can let me know I would greatly appreciate it!

Reply 317 of 335, by Boohyaka

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Both my MU80 had a soldered battery. I removed it and the unit wouldn't turn on at all, so the battery is part of the circuit and the answer to your question is unfortunately most probably no for the TG300 I suppose.

I had a few spare battery holders from another project so soldered that instead and it works fine, but guess you could just bridge it for continuity?

Reply 318 of 335, by eightbit

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Boohyaka wrote on 2022-04-25, 15:58:

Both my MU80 had a soldered battery. I removed it and the unit wouldn't turn on at all, so the battery is part of the circuit and the answer to your question is unfortunately most probably no for the TG300 I suppose.

I had a few spare battery holders from another project so soldered that instead and it works fine, but guess you could just bridge it for continuity?

I'll just add a battery holder at some point. Thanks for confirming!