VOGONS


First post, by PhoeniX98

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Hello, i'm new on this site, but i already knew him. Well, i have a problem with a Roland Sound Canvas SC-55 mkII that i purchased a week ago, and the problem is that it does not turn on, i tested it with any power adapter. Two power adapters that i tested, they showed a blinking light when i connected them to the unit.

I opened the unit, to see if the internal battery was installed, and has it, but besides, it seems to be no damage, except for a few small red stains, but i don't think it affects the unit. A friend says me that use the official power adapter manufactured by Roland, but i'm not convinced that the problem be the manufacturer. I have a Yamaha MU1000 and works fine with any adapter that's not Yamaha, as long as it complies with the required voltage, amperage and polarity. I don't know what the problem and i don't know it has solution.

I leave a image of the opened unit, if you can see what is something wrong. Perhaps you know more about this...

Spoiler

1647974294194-2.jpg

Reply 1 of 13, by SuperDeadite

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Only thing I can say is that Yamaha is typically Center Positive while Roland is typically Center Negative.

Modules: CM-64, CM-500, SC-55MkII, SC-88 Pro, SY22, TG100, MU2000EX, PLG100-SG, PLG150-DR, PLG150-AN, SG01k, NS5R, GZ-50M, SN-U110-07, SN-U110-10, Pocket Studio 5, DreamBlaster S2, X2, McFly, E-Wave, QWave, CrystalBlaster C2

Reply 2 of 13, by PhoeniX98

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SuperDeadite wrote on 2022-03-22, 23:34:

Only thing I can say is that Yamaha is typically Center Positive while Roland is typically Center Negative.

I already know that. In fact, one of the adapters that i tested, is center negative... didn't work either.

Reply 3 of 13, by Shreddoc

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Can you provide a close-up / macro shot of the top left area? Here at Vogons we have seen some units have issues in that region. i.e. corrosion around the base of the large capacitor. You may want to investigate that in order to confirm or rule it out.

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PhoeniX98 wrote on 2022-03-23, 00:24:
SuperDeadite wrote on 2022-03-22, 23:34:

Only thing I can say is that Yamaha is typically Center Positive while Roland is typically Center Negative.

I already know that. In fact, one of the adapters that i tested, is center negative... didn't work either.

Err.. are you implying that you've also tested adapters that are center positive, with this unit!?? I sincerely hope not. Using incorrect polarity power supplies is a very quick and sure way to repairsville, for many things.

Reply 4 of 13, by PhoeniX98

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Shreddoc wrote on 2022-03-23, 00:27:
Can you provide a close-up / macro shot of the top left area? Here at Vogons we have seen some units have issues in that region […]
Show full quote

Can you provide a close-up / macro shot of the top left area? Here at Vogons we have seen some units have issues in that region. i.e. corrosion around the base of the large capacitor. You may want to investigate that in order to confirm or rule it out.

1647974294194-2.jpg

PhoeniX98 wrote on 2022-03-23, 00:24:
SuperDeadite wrote on 2022-03-22, 23:34:

Only thing I can say is that Yamaha is typically Center Positive while Roland is typically Center Negative.

I already know that. In fact, one of the adapters that i tested, is center negative... didn't work either.

Err.. are you implying that you've also tested adapters that are center positive, with this unit!?? I sincerely hope not. Using incorrect polarity power supplies is a very quick and sure way to repairsville, for many things.

Spoiler

1648008183923.jpg

Err.. are you implying that you've also tested adapters that are center positive, with this unit!?? I sincerely hope not. Using incorrect polarity power supplies is a very quick and sure way to repairsville, for many things.

Honestly, yes. I only cared about the voltage and amperage, but i never care about the polarity, I don't even know what it is neither how it influences the operation of the equipment. I realized that, when i saw the PSB-120 adapter specs, this one show a symbol with a circle pointing to a (-), i used three adapters with the same symbol but with the circle ponting to a (+). I found an adapter in home, with negative polarity but with less voltage (6v), that was the last one i used.

What does that mean? That answer sounds worrisome to me. Is the first time that i use this devices, especially the SC-55.

Reply 5 of 13, by Shreddoc

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PhoeniX98 wrote on 2022-03-23, 04:30:
Shreddoc wrote on 2022-03-23, 00:27:

Can you provide a close-up / macro shot of the top left area? Here at Vogons we have seen some units have issues in that region. i.e. corrosion around the base of the large capacitor. You may want to investigate that in order to confirm or rule it out.

1647974294194-2.jpg

Thanks! I can't immediately diagnose from the image, but others may find it useful and may have opinions. But let's focus first upon the power adapter:

PhoeniX98 wrote on 2022-03-23, 00:24:

Err.. are you implying that you've also tested adapters that are center positive, with this unit!?? I sincerely hope not. Using incorrect polarity power supplies is a very quick and sure way to repairsville, for many things.

Honestly, yes. I only cared about the voltage and amperage, but i never care about the polarity, I don't even know what it is neither how it influences the operation of the equipment. I realized that, when i saw the PSB-120 adapter specs, this one show a symbol with a circle pointing to a (-), i used three adapters with the same symbol but with the circle ponting to a (+). I found an adapter in home, with negative polarity but with less voltage (6v), that was the last one i used.

What does that mean? That answer sounds worrisome to me. Is the first time that i use this devices, especially the SC-55.

First things first. Stop trying out different power supplies. Immediately, my friend. You can easily damage equipment by using the wrong power supply with it, even once. Never use that "try out a bunch of supplies, and see which one works" method again, with any equipment.

Second: You MUST use ONLY an adapter meeting ALL of the following specifications:
Voltage = 9 volts
Polarity = center-negative
Current = 1.0A (or 1000mA) is ideal, higher (or slightly lower) is ok.

My advice. Get ^one. Test the unit with it.

If it doesn't work with that correct adapter, then you've possibly done some damage by your earlier usage of incorrect adapters. The good news: that damage probably wouldn't be major - just one diode if you're lucky, a relatively quick repair for a skilled soldering iron.

Reply 6 of 13, by PhoeniX98

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Shreddoc wrote:

First things first. Stop trying out different power supplies. Immediately, my friend. You can easily damage equipment by using the wrong power supply with it, even once. Never use that "try out a bunch of supplies, and see which one works" method again, with any equipment.

Well, this same thing i made in my MU1000 the last year, but as i say, back then, i didn't notice about polarity, neither amperage, only the voltage. Good thing they were all center positive, in fact, the first that i used is of my Yamaha keyboard, until i get a Yamaha power adapter, but a days ago, i noticed that the adapter is 700mA, less than requires the unit (2A), and i worried that, because due to the lower amperage the equipment can be damaged. I stopped using it, but luckily, i found in home an adapter, that is not Yamaha, but complies accurately what is required (12v - 2A - center positive) (all this time was at home that adapter and never i noticed... i feel stupid).

I leave a pic of him to confirm.

Pic

1648061683109.jpg

Shreddoc wrote:
Second: You MUST use ONLY an adapter meeting ALL of the following specifications: Voltage = 9 volts Polarity = center-negative C […]
Show full quote

Second: You MUST use ONLY an adapter meeting ALL of the following specifications:
Voltage = 9 volts
Polarity = center-negative
Current = 1.0A (or 1000mA) is ideal, higher (or slightly lower) is ok.

My advice. Get ^one. Test the unit with it.

I will get the PSB-120, has a design that i don't like much, but is the only one that is center negative, while all the ones that i find are center positive, but besides this is 2A (more than you recommended), is suitable?

Shreddoc wrote:

If it doesn't work with that correct adapter, then you've possibly done some damage by your earlier usage of incorrect adapters. The good news: that damage probably wouldn't be major - just one diode if you're lucky, a relatively quick repair for a skilled soldering iron.

Is good to know that. Well, i will test with the PSB-120. I will save that post. Thanks for the advices, i'll keep it in mind, so i don't make the same mistake when i get another retro synth. Thanks!

Reply 7 of 13, by Shreddoc

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You're very welcome! I hope it works out for the best.

PhoeniX98 wrote on 2022-03-23, 19:52:

I will get the PSB-120, has a design that i don't like much, but is the only one that is center negative, while all the ones that i find are center positive, but besides this is 2A (more than you recommended), is suitable?

Yes the PSB-120 is perfectly suitable.

The 2A max Current rating of that adapter is fine. The PSB-120 is voltage regulated, meaning it will consistently deliver the rated 9V, whether loaded by a 100mA device, or the full 2000mA load, or anywhere in-between. Therefore, it will do no harm to your Sound Canvas. The Canvas will pull only the Current it needs.

The remainder of the PSB-120's Current capacity will simply sit unused, and the power supply unit will run cool & comfortable (and have a longer life span) as a result of that modest utilisation.

Reply 8 of 13, by igna78

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Hi, regarding your problem, I think it is due to the large capacitor on the power line: it is evident that it has leaked from below (i.e. the capacitor needs to be replaced .. and see to respect not only the polarity during installation, but also voltage, capacity and operating temperature of the original capacitor) and that you will have to replace it as well as clean up the traces around it to avoid corrosion.

Also pay attention to respect amperage, voltage and polarity even in the power supply

😉

Reply 9 of 13, by Shreddoc

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igna78 wrote on 2022-03-24, 01:00:

it is evident that it has leaked from below (i.e. the capacitor needs to be replaced)

It's understandable to come to that conclusion. You see a substance beside a capacitor. You assume capacitor leak. It's natural.

However, based upon previous discussions here at Vogons regarding that particular capacitor in Sound Canvas units, the community consensus is that the brown substance here is a type of adhesive. The substance has certainly been found to cause problems in the units of selected users, no doubt. (conversely, others with the substance have no corrosion)

But the first and obvious necessary thing in this situation, before anything else can be confirmed or denied, is to have the correct power supply.

Reply 10 of 13, by PhoeniX98

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Hello, it's me again. Finally the PSB-120 has arrived this morning (10 am GMT-3), i tested it and... WORKS! I was afraid it wouldn't work and possibly a diode would have been damaged (due to the testing with wrong adapters) but works, and now i enjoy it! Thanks again.

Shreddoc wrote on 2022-03-24, 02:21:
It's understandable to come to that conclusion. You see a substance beside a capacitor. You assume capacitor leak. It's natural. […]
Show full quote
igna78 wrote on 2022-03-24, 01:00:

it is evident that it has leaked from below (i.e. the capacitor needs to be replaced)

It's understandable to come to that conclusion. You see a substance beside a capacitor. You assume capacitor leak. It's natural.

However, based upon previous discussions here at Vogons regarding that particular capacitor in Sound Canvas units, the community consensus is that the brown substance here is a type of adhesive. The substance has certainly been found to cause problems in the units of selected users, no doubt. (conversely, others with the substance have no corrosion)

But the first and obvious necessary thing in this situation, before anything else can be confirmed or denied, is to have the correct power supply.

The red stains within the unit, is adhesive? I thought that are only stains... well i hope that don't cause problems in my unit. I used it, and i haven't had problems because of that until now.

Reply 11 of 13, by PhoeniX98

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Sorry for double posting, i don't want to divert the topic, but i have a doubt. Is normal that the LCD screen of my unit, turn it on automatically when i plug it? It should be in stand by mode, but my unit turn it on the screen without me pressing the power button. How i fix that?

Reply 12 of 13, by Shreddoc

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PhoeniX98 wrote on 2022-04-02, 20:37:

Sorry for double posting, i don't want to divert the topic, but i have a doubt. Is normal that the LCD screen of my unit, turn it on automatically when i plug it? It should be in stand by mode, but my unit turn it on the screen without me pressing the power button. How i fix that?

Yes that is normal behaviour, nothing to worry about.

Reply 13 of 13, by PhoeniX98

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Shreddoc wrote on 2022-04-02, 22:09:
PhoeniX98 wrote on 2022-04-02, 20:37:

Sorry for double posting, i don't want to divert the topic, but i have a doubt. Is normal that the LCD screen of my unit, turn it on automatically when i plug it? It should be in stand by mode, but my unit turn it on the screen without me pressing the power button. How i fix that?

Yes that is normal behaviour, nothing to worry about.

Thanks for the answer! I thought that was some bug.