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ChristoMephisto
Platinum Member
Canada
1288 Posts |
 Posted - 07/28/2008 : 14:53:56
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My DD3 stopped working about a month ago, and had some time to fix that beloved pedal.
Knew it gonna be the zener diode. After doing a google for RD11FB-3 diode, and gave me a hit to this forum where Dr.Bob was explaining examples of zeners, like the 1N4741 being a perfect match at 1W 11 volts. He also listed the 1N4747, which was a 1W 18 volt diode.
A friend brought over the latter one, and my DD3 lives again!!
Thanks to the Doc again for taking the guess work of a replacement.
When I pulled out the old one, I could see a crack in it under a 10x eye piece.
Also think there was a problem with that diode before, theres a burnmark on the plastic insulator and the leads were longer than the rest on the circuit board.
Funny thing is, I could measure voltage with both adapter and battery, but could only get the effect to work with a battery.
1/2 to 2 hours with magnesium, and 5-10 with alkaline, that would burn them up fast
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/28/2008 : 15:24:58
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quote:
Originally posted by ChristoMephisto
My DD3 stopped working about a month ago, and had some time to fix that beloved pedal.
Knew it gonna be the zener diode. After doing a google for RD11FB-3 diode, and gave me a hit to this forum where Dr.Bob was explaining examples of zeners, like the 1N4741 being a perfect match at 1W 11 volts. He also listed the 1N4747, which was a 1W 18 volt diode.
A friend brought over the latter one, and my DD3 lives again!!
Thanks to the Doc again for taking the guess work of a replacement.
When I pulled out the old one, I could see a crack in it under a 10x eye piece.
Also think there was a problem with that diode before, theres a burnmark on the plastic insulator and the leads were longer than the rest on the circuit board.
Funny thing is, I could measure voltage with both adapter and battery, but could only get the effect to work with a battery.
1/2 to 2 hours with magnesium, and 5-10 with alkaline, that would burn them up fast
Hi Christo.
You are welcome...
They use a Zener because they tend to blow short circuit, therefore generally protecting the rest of the circuit.
What search string did you use, when you search for it on Google?
You can also use a 12V 1W Zener, it's better than using nothing at all.
it's good practice to place the proction diode, above the PCB, to minimize damage to the PCB.
Also don't forget, a quick rule of thumb, if you leave an extra 10mm of lead length on the Zener, it adds approximately another (1) watt to the dissipation spec.
You will see this in a lot of older consumer Japanese electronics gear.
Regards Dr. Bob.
3232 |
Edited by - Dr. Bob on 07/28/2008 15:26:27 |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 07/28/2008 : 15:51:04
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I used RD11FB-3 diode
Bossarea Forum - Non working DD-3
Can I measure the resistance over the diode and by that way find that it is ..... A RD11FB3 is a 11 volt 1 watt zener here are some links to help prove it. ...
www.bossarea.com/forum/topic.asp?TOPIC_ID=2790&whichpage=2 - 77k - Cached - Similar pages
about half way down, to Goran's thread of non-working DD-3
10mm past the solder joint on the solder side?
Its wired vertical, with the stripe down |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/28/2008 : 16:06:47
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quote:
Originally posted by ChristoMephisto
I used RD11FB-3 diode
Bossarea Forum - Non working DD-3
Can I measure the resistance over the diode and by that way find that it is ..... A RD11FB3 is a 11 volt 1 watt zener here are some links to help prove it. ...
www.bossarea.com/forum/topic.asp?TOPIC_ID=2790&whichpage=2 - 77k - Cached - Similar pages
about half way down, to Goran's thread of non-working DD-3
10mm past the solder joint on the solder side?
Its wired vertical, with the stripe down
Hi Christo
10mm above the PCB -- (component side).
Better if it's 10mm on both ends, it basically acts like a simple heatsink, either side of the diode.
Regards Dr. Bob
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 07/28/2008 : 16:11:06
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Its about that one one side, thx learned something new |
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My DD3 stopped working, but...
