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americanmonk
Copper Member
USA
13 Posts |
 Posted - 08/21/2008 : 20:43:41
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Long time lurker, first time poster. So I was playing with my DM-2 hooked up via TU-2 daisy chain (Guitar > TU-2 > DS-1 > DM-2 > Amp) when I started to smell that dreaded "something is frying smell." I immediately turned everything off and inspected each pedal. I tried each one of them by themselves thru the amp and they all worked normally until I got to the DM-2. Now excuse my lack of knowledge concerning electronics terminology, but what I see is 1 fried component that I can describe as a "small red cylinder lying down" right below the point attached to number 10.
So I called up Roland, sent them the pedal, they inspected it and then told me they couldn't fix it. They told me the part they need to fix it doesn't exist anymore. I couldn't get it out of them if it was the ENTIRE board that needs replacement... or just that one component. So my question to you knowledgeable Forumites is simply, what should I do? Thanks in advance!
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bossarea
Forum Admin
United Kingdom
3652 Posts |
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americanmonk
Copper Member
USA
13 Posts |
Posted - 08/21/2008 : 21:02:37
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Thanks for such a quick response! Yes the fried component is the "small circular red piece" directly under the #10 on the board. Thanks for your help!
Edit: It looks like from the schematic you provided the part is named "D4 : RD11EB3" |
Edited by - americanmonk on 08/21/2008 21:05:48 |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/21/2008 : 21:32:02
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This shouldn't be a problem... please post some closeup pics of both sides of the board.
PS: welcome and congrats on "de-lurking"  |
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americanmonk
Copper Member
USA
13 Posts |
Posted - 08/21/2008 : 21:33:49
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Hey Laurie,
They just sent out the pedal to me yesterday, I expect it back at the end of the week/start of next week. Once I get it back, I'll post pics. Thanks! |
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americanmonk
Copper Member
USA
13 Posts |
Posted - 08/21/2008 : 21:52:17
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| Over at The Gear Page we've confirmed it is indeed the RD11EB3 Diode made by NEC. They aren't made anymore, but I am wondering if anyone knows if any components of the same values are currently being made? Thanks. |
Edited by - americanmonk on 08/21/2008 22:03:27 |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 08/21/2008 : 22:29:54
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| The component is a generic 11V zener diode. You don't need the same manufacture, the component doesn't have anything to do with the pedals sound. It's just there to protect against wrong polarity or too high voltage from the power supply. You should be able to find a replacement part anywhere they sell electronic components. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/21/2008 : 23:28:44
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quote:
Originally posted by bossarea
The component is a generic 11V zener diode. You don't need the same manufacture, the component doesn't have anything to do with the pedals sound. It's just there to protect against wrong polarity or too high voltage from the power supply. You should be able to find a replacement part anywhere they sell electronic components.
All true, and a 12V one works too (I acutally us 13V 5W ones in my own pedal designs).
Even better - just remove it and make sure you use a PSA supply and that will tell you if the pedal is still working. But make sure you replace it before putting the pedal back into general use.
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americanmonk
Copper Member
USA
13 Posts |
Posted - 08/21/2008 : 23:58:29
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| Ok so I found and ordered a replacement part for it, but for now... you're saying I could just remove the existing fried zener diode and then see if the pedal functions normally using the normal PSA adaptor? Using it without a working diode in it wouldn't hurt it at all? Thanks so much for all your input. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/22/2008 : 02:24:23
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quote:
Originally posted by americanmonk
Ok so I found and ordered a replacement part for it, but for now... you're saying I could just remove the existing fried zener diode and then see if the pedal functions normally using the normal PSA adaptor? Using it without a working diode in it wouldn't hurt it at all? Thanks so much for all your input.
If you use a Boss PSA adapter, no harm will come to your pedal. Note though that whatever fried the diode may have also damaged other components - so it it doesn't work there will be more stuff for us to chase. The good news is that all the parts for a DM-2 are available - for a price |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 08/22/2008 : 10:45:13
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quote:
Originally posted by Laurie
If you use a Boss PSA adapter, no harm will come to your pedal.
Or you could connect it to a battery.
If it was the adapter that caused the fryup in the first place you will want the protection diode in place before you connect it to the same adapter again. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/22/2008 : 15:13:31
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| True - let me rewrite mt statement... "if you connect it to a known good Boss PSA adapter no harm will come to it" |
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americanmonk
Copper Member
USA
13 Posts |
Posted - 08/24/2008 : 07:10:00
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| I de-soldered the burnt diode off and plugged it into a Boss PSA adaptor and everything worked fine. I'll still wait to do anything with it until the replacement part shows up. Anyway, I'll keep you guys posted. Thanks for your help! |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 08/24/2008 : 07:19:42
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Hi americanmonk & Guys
It would be interesting to hear what you think fried the Protection Zener?
I have re-read your first post, & still can't figure out what actually happened.
Was one of the connections on the daisy chain reversed?
Or was the Power adapter something other than a PSA, & was way over voltage?
It's great to hear that you have it working again, & nothing else was fried on the PCB.
especially being a DM-2 pedal.
Regards Dr. Bob
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 08/24/2008 : 07:29:02
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| Great stuff! Congrats on rescuing a classic pedal! |
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americanmonk
Copper Member
USA
13 Posts |
Posted - 08/24/2008 : 09:10:08
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Dr. Bob,
I had my TU-2 powered by one of the 9v outputs on a DC Brick, then daisy chained to a MIJ DS-1 then the DM-2. Thats when I started smelling the burn smell. I have run plenty of Boss pedals thru the DC Brick, so it's interested to me that it happened like this. |
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Topic |
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Fried Boss DM-2
