Roland SR-JV80 expansion cards - risk of capacitor explosion

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kvitekp
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Roland SR-JV80 expansion cards - risk of capacitor explosion

Post by kvitekp » Wed Feb 07, 2018 3:47 am

Just posted this on gearslutz, but due to the nature of the problem and popularity of Roland SR-JV80 expansion cards, it's worth re-posting it here. Original thread (with scary photos of results of an actual explosion) can be found here: https://www.gearslutz.com/board/electro ... st13125507

I've opened my beloved JD-990 today and checked 100uF 6V capacitor found on SR-JV80-04 Vintage Synth Expansion Card using LCR meter. I'm glad I did! Capacitor's ESR was 4.2 Ohm which is way to much for a 100uF cap, so I replaced it with a 100uF 25V SMD cap I happened to have on hand. The replacement cap is Nichicon UCW1E101MCL1GS (Digikey part # 493-9418-1-ND) with 7000 Hrs lifetime @ 105°C. Measured ESR is now 0.8 Ohm, which is about right.

High ESR means that electrolytic capacitor dried up and is losing its properties. Since JD-990 digital electronics is powered by +5V, that 100uF cap rated for 6V has very little margin and when degraded, has high chance of exploding. So it's a ticking bomb :( If you are using SR-JV80 cards, you must replace that electrolytic capacitor as soon as possible. Roland's recommendation to stop using these cards on their Japanese site is no joke. I wonder why they did not post it on English site.

Roland's note can be found here: https://www.roland.com/jp/support/support_news/170119/

Automatic translation:
----
To Expansion Board SR-JV80 Series Customers

Published January 27, 2017

Thank you very much for your patronage of our products on a daily basis.

Expansion board SR-JV80 series has been in production for more than 20 years since its initial production, electrolyte in use may rarely leak due to aged deterioration of electrolytic capacitor used.
If electrolyte leaks out, in the worst case there is a risk of smoking.
Customers who are currently using SR-JV80 series with sound module or synthesizer should stop using it immediately.

If you plan to continue using this SR-JV80 series in the future, please consult the Roland customer consultation center.

Roland Customer Consultation Center 050-3101-2555
* Follow the voice guidance, please press the repair reception desk "1 #".

Reception hours: Monday to Friday 10: 00 ~ 17: 00 (excluding holidays and our defined holidays)

We sincerely apologize for any inconvenience this may cause to customers who use our products. From now on, we will strive to further improve the quality. Thank you for your consideration.
---

Image

Image

/Peter
www.midisizer.com -- home of MidiALF MIDI/CV step sequencer, MidiREX MIDI looper, MidiGAL MidiClk/MidiArp/MidiSeq and other Synth DIY stuff

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sutekina bipu-on
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Post by sutekina bipu-on » Wed Feb 07, 2018 4:48 am

I almost bought a jv80 card recently. Glad I didn't! Though it makes me wonder if i should give my M-SE1 a more thorough inspection, even though their notice doesn't mention the sound expansion series.

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Don Solaris
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Post by Don Solaris » Fri Feb 09, 2018 8:38 am

Video with instructions on how to fix the problem:


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daveholiday
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Post by daveholiday » Fri Feb 09, 2018 3:39 pm

Thanks for posting this!! I have a Roland JV-1080 in my rack that is my goto synth for rompler type sounds. The three expansion boards in mine are the old style single 6v caps. While they have no visual signs of leaking (and I don't have an LCR meter) I still may source some replacement caps! There have got to be a ton of these cards floating around...surprised there haven't been more reports of failure.

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sutekina bipu-on
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Post by sutekina bipu-on » Fri Feb 09, 2018 7:11 pm

daveholiday wrote:Thanks for posting this!! I have a Roland JV-1080 in my rack that is my goto synth for rompler type sounds. The three expansion boards in mine are the old style single 6v caps. While they have no visual signs of leaking (and I don't have an LCR meter) I still may source some replacement caps! There have got to be a ton of these cards floating around...surprised there haven't been more reports of failure.
Its like the original Xbox's clock capacitor story, it's a problem that would affect all units, but not until they've all got old enough for the change which causes the problem to occur. So it happens to one person and they get online to mention it and then it just happens more frequently to more people as time goes on and the devices aren't repaired. It's not a "wait until it happens" thing.

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1986Bowler
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Post by 1986Bowler » Mon May 20, 2019 10:07 pm

I just got my JV-1080 about a month ago, with the intention to get some expansion cards.

I found an SR-JV80-02 Orchestral locally. Brought it home, but I didn't rush to plug it in. I don't know why exactly.

In my search for information about how to install the card, I found the YouTube videos warning about the cap issue.

Got a cap- just need to install it.

Guess Roland didn't expect us to be playing stuff from so long ago with such eagerness!

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ranix
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Post by ranix » Tue May 21, 2019 7:11 am

wow that's crazy, I would never have considered this capacitor a risk

I didn't even inspect the expansion cards I have installed in my synthesizer, or think to check how old they are...

thanks for posting this

Panason
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Post by Panason » Tue May 21, 2019 1:29 pm

Customers who are currently using the SR-JV80 series with sound module or synthesizer should stop using them immediately.
Japan.

I must say, even though it sucks for the owners, the concept of exploding digital synths is quite good.

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Post by strumm » Thu Sep 12, 2019 11:00 am

Hi,

My first muffwiggler post.

I just received a JD-990 with the vintage synth expansion board. I want to remove the expansion board to check the capacitor with an LCR.

The manual says use the 'Locking Tool' to turn those white posts to unlock the board. I've seen photos of the plastic tool. Is there any source to buy this tool?

2nd question. If I get the board out, and the ESR reading is normal. Is it still essential to swap out the capacitor?

thanks!
strumm

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BenA718
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Post by BenA718 » Thu Sep 12, 2019 5:46 pm

Thanks for posting this! I have a fully loaded JV-880 and JV-1080 and will be checking the expansion cards in both!

strumm
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Post by strumm » Sat Sep 14, 2019 1:28 pm

Thanks to kvitekp!

He sent me this video which shows you can simply use pliers to turn the white posts. You don't need the Roland tool.

Removing JV-80 Board


He also told me that the capacitor pole to the left on his pictures above ( closest to edge of expansion card ) is the negative.

My capacitor tests at ESR 2.6

I'm going to order a capacitor and get it swapped.

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Post by Paranormal Patroler » Mon Sep 16, 2019 9:58 am

Does anyone know if this is also an issue for the SRX type of cards? :sadbanana:
All rights reserved; all wrongs reversed.

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peanut
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Re: Roland SR-JV80 expansion cards - risk of capacitor explosion

Post by peanut » Thu Jul 09, 2020 11:23 pm

I could post this in the DIY space but thought someone who replaced a cap on the SR-JV80 might be able to help.

I need some guidance on choosing a capacitor. I don't know enough about electronics to understand the difference between some of the mouser parts I'm looking at. And just to pre-empt any concerns about safety, I'm fully aware that I need to solder the leads to the correct poles or risk explosion when turning on the unit. I'm looking at radial, aluminum electrolytic caps 100uF at least 6.3 VDC rating. Specifically the "life" for some of these caps seems super low ~1 or 2 thousand hours. A couple caps with higher voltage ratings are estimated at 10k hours. I'm hoping to not have to replace the cap again for the next couple of decades. A second concern is whether I should only be looking at "audio-grade" caps. What's my best bet?

Thanks in advance

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Re: Roland SR-JV80 expansion cards - risk of capacitor explosion

Post by Flounderguts » Thu Jul 09, 2020 11:43 pm

peanut wrote:
Thu Jul 09, 2020 11:23 pm
I could post this in the DIY space but thought someone who replaced a cap on the SR-JV80 might be able to help.

I need some guidance on choosing a capacitor. I don't know enough about electronics to understand the difference between some of the mouser parts I'm looking at. And just to pre-empt any concerns about safety, I'm fully aware that I need to solder the leads to the correct poles or risk explosion when turning on the unit. I'm looking at radial, aluminum electrolytic caps 100uF at least 6.3 VDC rating. Specifically the "life" for some of these caps seems super low ~1 or 2 thousand hours. A couple caps with higher voltage ratings are estimated at 10k hours. I'm hoping to not have to replace the cap again for the next couple of decades. A second concern is whether I should only be looking at "audio-grade" caps. What's my best bet?

Thanks in advance
Yeah, post this in the DIY subforum.

Generally, if the size of the cap and lead spacing are the same, or will fit, get a higher voltage spec. Caps are cheap, especially electrolytic caps, so it's not a burden to go for a higher voltage rating. I generally use at least a factor of 5 (25V for 5V application, 63V for 12 V application...) as long as the size is ok.
You haven't said what the cap is for, so I can't comment on audio-grade, but if it's not in the signal path, you can safely skip audio-grade.
As for getting it oriented correctly, you should mark the negative side on the board(there's a stripe there) and just make sure the new one goes in the same. Often there will be a flat side on the silkscreen, or a +/-, or even a round and square pad (or all three) to help you get it right.
Also, at Mouser buying 10 caps is often cheaper than buying 1, and shipping is steep for a small number of components. Probably a fellow Wiggler would have a cap like that lying around, and would be happy to mail you one.

Good luck!
----------------------

Flounderguts

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peanut
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Re: Roland SR-JV80 expansion cards - risk of capacitor explosion

Post by peanut » Fri Jul 10, 2020 6:59 pm

That's really helpful-- thanks!

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