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Goran
Double Platinum Member
Sweden
2203 Posts |
 Posted - 04/10/2007 : 07:53:14
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I have just traded a TS-5 for a non-working DD-3 (an early one) and I have searched the forum as I remember this has been up sometimes, but couldn�t find anything.
The only thing I remember is that there should be a diode of some kind protecting the circuit.
The problem;
Neither with battery or PSA there is no sound at all (no direct/no delayed sound), no light from the LED.
Anyone has any theories?
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mattoqua
Silver Member
Canada
438 Posts |
Posted - 04/10/2007 : 08:37:31
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| I dont know too much about electonics, but it might just be a scratch on the pcb at the input of the circuit. It would stop everything from working. |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 04/10/2007 : 08:49:27
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| I have tested the battery connector, the DC-input and a �bit� inside for loosened connections but havn�t found anything abnormal. |
Edited by - Goran on 04/10/2007 08:50:30 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/10/2007 : 09:06:17
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Hi Goran
If I remember correctly, on the DD-2 it's D46
But don't quote me on that one.
As, I don't have the schematic with me at the moment.
Look around the DC in part of the PCB, there will be a slightly bigger maybe glass diode protection the circuit.
I think D46 was a bit further in on the schematic. I think it was Bossarea, that had a few of the DD-2's that he fixed.
I'll have a look at the schematic, when I get a chance.
Regards Dr. Bob |
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Goran
Double Platinum Member
Sweden
2203 Posts |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/10/2007 : 15:52:06
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Hi Goran
First of all "Sorry about leading you up the wrong path"
It was D6, that I was thinking about, & not D46
Ok the original posting about the dead D6 Zener was by:
stahlhart
I have done a search on the forum, for: shorted D6 Zener
Search - last year.
And it has come back with this info:
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=982&SearchTerms=shorted,D6,Zener
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=1791&whichpage=1&SearchTerms=shorted,D6,Zener
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=436&SearchTerms=shorted,D6,Zener
If you read all the above links, you should get a clearer picture of the possible fault.
I hope this helps you out.
Sorry about the delay in re-posting.
Please let us all know, how you get on.
On the schematic D6 is near the top Left Hand side, about 1/3 of the way down.
It feeds the 6V regulator IC10, check that the output of IC10 is about 5VDC, it may have also been damaged.
In my experience, the 78L series regulators as in the, 78L05 regulators are easily damaged, the are in a small TO92 package, like a small signal transistor or like the bypass FET's.
The 78L series, only supply about 100mA of current, And I have replaced a few 5 Volt, 78L05 regulators in my time.
Regards Dr. Bob 
PS thanks to "stahlhart" as well, for his older posts. |
Edited by - Dr. Bob on 04/10/2007 16:00:49 |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 04/11/2007 : 07:30:40
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Thanks a lot Dr Bob!.... and Stahlhart.
As I�m far from an electronic wizard I won�t do this at once, I have to build up courage enough to do this. But now there is a plan, a possibility to do it.
Of course I will report the outcome when I tried the suggested manoeuvres.
I would be glad if it works out as the DD-3 is from November 1986, one of the earliest.
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/11/2007 : 14:49:49
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quote:
Originally posted by Goran
Thanks a lot Dr Bob!.... and Stahlhart.
As I�m far from an electronic wizard I won�t do this at once, I have to build up courage enough to do this. But now there is a plan, a possibility to do it.
Of course I will report the outcome when I tried the suggested manoeuvres.
I would be glad if it works out as the DD-3 is from November 1986, one of the earliest.
Good Luck Goran, I know you can do it.
Just re-read all the postings, so you get a good idea about the repair.
Or maybe have a Technical friend help you out.
Print off the DD-2/3 Schematic, to help, both him & yourself out.
Regards Dr. Bob 
PS We are always here on line to help you out. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/11/2007 : 15:19:50
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Hi Everyone.
Does anyone here have a photo of the board of a DD-3 maybe the DD-2, that might show the location of the offending D6 zener diode.
I am sure this would help Goran immensely.
I'm also sure, that there was a link on one of the posts, on this board, that had a pic of the different chips used in the DD-2,
Maybe one of those pics shows the location of the zener.
Thanks in advance guys.
Regards Dr. Bob |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 04/12/2007 : 08:13:57
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Thanks again Dr Bob!!
Of course a picture of where the diode i placed would help, but I think I will find it anyway. The main problem is that a packed PCB is a delicate thing to put a soldering iron on� I have build myself some pedals over the years, like Fuzz face, but nothing near as complicated as a digital delay.
Is there a way that I can see that the zener diode is bad??? Or the only way is to measure it?
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Edited by - Goran on 04/12/2007 08:14:57 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/12/2007 : 09:52:53
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quote:
Originally posted by Goran
Thanks again Dr Bob!!
Of course a picture of where the diode i placed would help, but I think I will find it anyway. The main problem is that a packed PCB is a delicate thing to put a soldering iron on� I have build myself some pedals over the years, like Fuzz face, but nothing near as complicated as a digital delay.
Is there a way that I can see that the zener diode is bad??? Or the only way is to measure it?
Hi Goran
It's probably best to measure it.
Just take your time, & as I said previously, see if you can find a Tech friend to help you.
I sometimes take a bunch of Digital Pic's of the pedal, as I'm working on it, just in case I forget where something goes, & for future reference,
Regards Dr. Bob |
Edited by - Dr. Bob on 04/12/2007 09:54:01 |
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guirat
Silver Member
United Kingdom
186 Posts |
Posted - 04/18/2007 : 04:01:06
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I got my DD-3 working again briefly, after resoldering the wires to the input & output jacks, but its gone again, pass-through signal only, it seems to be pot luck when I switch it on whether it works or not. I see a lot of posts about non-working DD-3's, was it an overly-complicated circuit? Delicate components?
My previously working TW-1 has also failed again. They're dropping like flies..
I fixed this before by cleaning out the switch with contact cleaner, I think there must be some dirt in there that's impeding the circuit, maybe time for a stripdown of the switch and full check of all the pedal connections.
Edit>> I appear to have fixed my DD-3, I was trying it out once again and decided to remove the backplate whilst it was switched on. To my surprise it started working - I'd never taken the plate off whilst the unit was switched on before, as I assumed the plate needed to be in contact with the 2 prongs on the PCB for the pedal to function. I do have the plastic shield in there, so I'm not sure what is being pressed against what and causing a short, but I managed to put the plate back on and maintain functionality. All that time it sat idle when it was really an easy fix! Though I've thought I had it fixed before, will see how long it lasts.. |
Edited by - guirat on 04/20/2007 22:04:48 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/21/2007 : 04:13:45
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quote:
Originally posted by guirat
I got my DD-3 working again briefly, after resoldering the wires to the input & output jacks, but its gone again, pass-through signal only, it seems to be pot luck when I switch it on whether it works or not. I see a lot of posts about non-working DD-3's, was it an overly-complicated circuit? Delicate components?
My previously working TW-1 has also failed again. They're dropping like flies..
I fixed this before by cleaning out the switch with contact cleaner, I think there must be some dirt in there that's impeding the circuit, maybe time for a stripdown of the switch and full check of all the pedal connections.
Edit>> I appear to have fixed my DD-3, I was trying it out once again and decided to remove the backplate whilst it was switched on. To my surprise it started working - I'd never taken the plate off whilst the unit was switched on before, as I assumed the plate needed to be in contact with the 2 prongs on the PCB for the pedal to function. I do have the plastic shield in there, so I'm not sure what is being pressed against what and causing a short, but I managed to put the plate back on and maintain functionality. All that time it sat idle when it was really an easy fix! Though I've thought I had it fixed before, will see how long it lasts..
Hi guirat
I had a intermittent with my newly acquired DD-2 - it turned out to be the metal foil shield.
it is plastic coated on both sides, but there are some places on the edges of the foil shield that were exposed & not insulated.
It turned out that the edge of the foil was shorting out the input connector,
So similar to you, I only had pass through mode.
I moved it around a bit till it no longer was shorting out on the input socket.
Hope this helps.
Regards Dr. Bob |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 04/23/2007 : 08:04:57
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Have followed the suggestions from Stahlhart regarding the zener diod D6, but it fine it looks like. The battery wasn�t heating up as supposed (with a shorted zener).
So I�m back where I started�.. suggestions?
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/23/2007 : 11:08:20
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Hi Goran
Here are some pictures of the inside of the different types of DD-3
Sorry it doesn't show the other side of the PCB.
Fro Stinkfoot's site.
http://www.stinkfoot.se/andreas/diy/articles/DD3.htm
Did you check that the foil shield wasn't shorting out on something.
I have also heard, that the soldering to the interconnection wires goes bad on some of the DD-2-3's
Regards Dr. Bob |
Edited by - Dr. Bob on 04/23/2007 11:08:43 |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 04/23/2007 : 12:33:18
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Thanks DR Bob!
I�ll have a look inside again, and really check the interconnections. |
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Topic |
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Non working DD-3
