pitchshifter wrote on 2024-02-19, 13:25:

Yes looks the same, Sega is 10v, but i think is no issue. The rest seems the same, so i dont understand why it shorted.

Yeap I used a sega PSU on my MT-32 for well over a year before buying one of the more modern Roland replacements. No issues at all as the 7805 inside the MT-32 can handle that 1v extra easily.

I agree that 9V vs 10V shouldn't be an issue. Now that I think about it, I do seem to recall one of my Roland synthesizers producing messed up sound when I used the wrong power supply that was underpowered. I have several Roland branded DC power supplies and grabbed the wrong one at the time.

It's very possible that there is a fault in the power supply that's preventing it from supplying enough power. This isn't always observable with a multimeter, as the voltage might only drop under load.

Maybe the blown fuse from the Sega power supply is an indicator. Or maybe the fault with the power is on the board.

Are you absolutely certain that you didn't insert one of the replacement capacitors in backwards?

Kahenraz wrote on 2024-02-19, 19:11:

I agree that 9V vs 10V shouldn't be an issue. Now that I think about it, I do seem to recall one of my Roland synthesizers produ […]
Show full quote

I agree that 9V vs 10V shouldn't be an issue. Now that I think about it, I do seem to recall one of my Roland synthesizers producing messed up sound when I used the wrong power supply that was underpowered. I have several Roland branded DC power supplies and grabbed the wrong one at the time.

It's very possible that there is a fault in the power supply that's preventing it from supplying enough power. This isn't always observable with a multimeter, as the voltage might only drop under load.

Maybe the blown fuse from the Sega power supply is an indicator. Or maybe the fault with the power is on the board.

Are you absolutely certain that you didn't insert one of the replacement capacitors in backwards?

Yes, the capacitors are well marked in the board, no margin for error.
Tomorrow i will have the replacement diode, and i will take some pics on the power part of the board.

I see some discoloration on the PCB beneath that large black filter capacitor. Are you certain that the brown glue did not damage any of the traces there? Even though the trace may appear to be visible, it could have corroded away beneath the solder mask.

Kahenraz wrote on 2022-01-19, 04:34:

While cleaning the area, I could feel my probe fall through the surface where a nearby trace should have been and glide along its path like an empty trench.

PCB destroying adhesive found in my Roland Sound Canvas SC-55mkII (inspect your synthesizer!)

Diode replaced, we have bad sound again!!
Do i try again with mega drive psu?
I also took off the big capacitor to check better, i dont see any cut traces, do you?

It looks like that whole area around the capacitor is mostly ground plane. The traces at probably on the other side of the board and should be fine.

Try measuring the voltage on the DC power jack with a multimeter to see if it's dropping too low. I would recommend another power supply regardless, since I do recall having a similar issue with bad sound due to an underpowered PSU. It's up to you if you trust the SEGA power supply. Try checking it on a multimeter as well, as well as verifying the polarity.

Hello all, solved.. After this, i was going to quit on the sc-155.

It was the 4x female rca Jack.. The solder was New, but i replace it anyway and voila!!
😅💪💪

Thank you all!!

Kahenraz wrote on 2024-01-30, 19:34:

If you already replaced the capacitors, you may add well try reflowing the connectors. I found cracks in the solder connections for the output jacks on several of my synthesizers when I last inspected them for refurbishment.

It's possible that there are cracks but they aren't visible to the naked eye in your case.

Roland SC-55 Refurbishment

This was my very first suggestion. 🤦

pitchshifter wrote on 2024-02-01, 15:05:

Well, just done it but was no good... it's with same issue.
Any more ideas of what should i seek?

🤷

Kahenraz wrote on 2024-03-01, 00:36:

This was my very first suggestion. 🤦 […]
Show full quote

Kahenraz wrote on 2024-01-30, 19:34:

If you already replaced the capacitors, you may add well try reflowing the connectors. I found cracks in the solder connections for the output jacks on several of my synthesizers when I last inspected them for refurbishment.

It's possible that there are cracks but they aren't visible to the naked eye in your case.

Roland SC-55 Refurbishment

This was my very first suggestion. 🤦

pitchshifter wrote on 2024-02-01, 15:05:

Well, just done it but was no good... it's with same issue.
Any more ideas of what should i seek?

🤷

Hello, but i did reflow the solder, many times.
I probably didn't explain me well 😀
I guess it was the rca connector that was somehow broke, i replace it for a new one.

Best regards

Oh, I see. You replaced the whole connector. I thought you meant new solder.

Hi All,

I have just removed a battery from my 55MKI and indeed was leaking a bit (nothing serious). Anyway, once I put the device ON again I am not getting battery low message? Is it normal? I thought it is shown on boot?

thanks, M.

mikesk8 wrote on 2024-03-08, 11:42:

Hi All,

I have just removed a battery from my 55MKI and indeed was leaking a bit (nothing serious). Anyway, once I put the device ON again I am not getting battery low message? Is it normal? I thought it is shown on boot?

thanks, M.

yes this is normal and you can ignore it completely

keropi wrote on 2024-03-08, 12:07:

mikesk8 wrote on 2024-03-08, 11:42:

Hi All,

I have just removed a battery from my 55MKI and indeed was leaking a bit (nothing serious). Anyway, once I put the device ON again I am not getting battery low message? Is it normal? I thought it is shown on boot?

thanks, M.

yes this is normal and you can ignore it completely

Thanks for the answer. So there is no "battery low" message at all if you remove the battery completely?

mikesk8 wrote on 2024-03-08, 12:14:

keropi wrote on 2024-03-08, 12:07:

mikesk8 wrote on 2024-03-08, 11:42:

Hi All,

I have just removed a battery from my 55MKI and indeed was leaking a bit (nothing serious). Anyway, once I put the device ON again I am not getting battery low message? Is it normal? I thought it is shown on boot?

thanks, M.

yes this is normal and you can ignore it completely

Thanks for the answer. So there is no "battery low" message at all if you remove the battery completely? UPDATE: it shows the batter low message only on 1st boot 😉

mikesk8 wrote on 2024-03-08, 12:14:

Thanks for the answer. So there is no "battery low" message at all if you remove the battery completely?

I have not seen this message on the MK1 , to my knowledge only MK2 displays it

keropi wrote on 2024-03-08, 13:51:

mikesk8 wrote on 2024-03-08, 12:14:

Thanks for the answer. So there is no "battery low" message at all if you remove the battery completely?

I have not seen this message on the MK1 , to my knowledge only MK2 displays it

It displays on my MKI on the first boot only.

Yes, it only showed once in my sc-155 also.

This thread has lived rent free in my head for the longest time. And today I used this knowledge.

Luckily, no leakage onto other components.

Bought a mk1, 1.20, seller claimed he was the first owner. He had no recollection of changing the battery.

My SC-55mkII was still sealed and had the original battery in it. After so many years, still 2,5V, of course I replaced it.

It seems prudent for all midi modules to fetch out and replace or remove the original battery.

Grabbed a Yamaha MU80 recently off ebay. It also had a coin cell battery. Seller attempted to replace soldering in battery with another, trying to solder a wire to the top of it. As can be expected, it didn't go well, as you can't solder wire onto a battery and they used a bit of tape to try and keep their new battery on it.

So even though the battery tested good, it complained about low battery on bootup, prompting me to open it and discover the stodgy workmanship. Thankfully, my soldering iron seems to be better, and I removed the replacement battery, the remains of the original battery terminals, and installed a new CR2032 battery holder. While the CR2032 is significantly smaller in capacity to the original CR2450, it is way easier to get CR2032s and more frequent replacement isn't a problem now it is in a holder.