Diamond D7104 problems. - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 20th August 2012, 05:44 AM   #1
diyAudio Member
 
Join Date: Aug 2012
Default Diamond D7104 problems.

So Im looking into buying a broken Diamond D7104. I am no electronics engineer.. but I know a guy whose got a ton of experience in the field and is OK with taking a look at it.

I have found 2 of these.

1- Is missing an inductor (what my buddy called it) inside the unit, and is missing 2 of the 6 caps inside of it. It powers on just fine, but only 1 of the 4 channels is working.

2- Hasnt been touched as far as I can tell, but from what little info I have on it when powered on the red power light flickers on and off.. and obviously no sound.


Any ideas as to what could be wrong with either? Especially the first one.
  Reply With Quote
Old 20th August 2012, 06:48 PM   #2
diyAudio Member
 
Join Date: Dec 2005
Location: Northern California
1: These amps had problems with the inductor shorting out. It may have been pulled by someone prior to your ownership. Its a very common issue with Diamond/Esoteric amps of this series. A suitable replacement will have to be hand made most likely for the amp to be original and as intended....
  Reply With Quote
Old 20th August 2012, 08:41 PM   #3
diyAudio Member
 
Join Date: Dec 2005
Location: Northern California
2: the second amp could have lots of possible reasons for not powering on. The red led flickering on and off sounds like the internal protection circuitry shutting the amp down after it detects issues inside the amp. but this is just a guess without any internal pics of the amp to view, and or hands on diagnosis of its symptoms...
  Reply With Quote
Old 20th August 2012, 09:37 PM   #4
diyAudio Member
 
Join Date: Aug 2012
Quote:
Originally Posted by 1moreamp View Post
1: These amps had problems with the inductor shorting out. It may have been pulled by someone prior to your ownership. Its a very common issue with Diamond/Esoteric amps of this series. A suitable replacement will have to be hand made most likely for the amp to be original and as intended....
Hand made? That doesnt sound like fun. Can they not be bought close to the original quality?

That would make sense though. I told my buddy it was missing an inductor and heres what he said.

"The only way that thing, could have come loose is if one of the outputs shorted and pulled a ton of current, heating up the solder joints and then it just fell out, I've seen that before. The missing Caps are odd, either they were never installed, because some amps are the same for several models so they just don't put all of the parts in, or someone has had it open, impossible to tell without looking at the solder joints first hand."


The guy who has the amp now has never opened it, but he bought it from someone else. More than likely, the caps have been missing from a long time ago, but the inductor coming off may be new. It is still bouncing around inside the amp.
  Reply With Quote
Old 20th August 2012, 09:40 PM   #5
diyAudio Member
 
Join Date: Aug 2012
Quote:
Originally Posted by 1moreamp View Post
2: the second amp could have lots of possible reasons for not powering on. The red led flickering on and off sounds like the internal protection circuitry shutting the amp down after it detects issues inside the amp. but this is just a guess without any internal pics of the amp to view, and or hands on diagnosis of its symptoms...
That would make sense. The guy told me that he is going off memory that is whats wrong with it.. he didnt check first hand, and he said he wont because hes selling it as is or for parts.

My EE buddy said neither would be easier to fix than the other, especially without being able to diagnose them on hand.. so its a matter of which I get cheapest. I am leaning towards the one with the screwed up power supply/short.

How do you keep the inductor from shorting out? I dont want to have this amp fixed and it blow up on me later with a common issue.
  Reply With Quote
Old 20th August 2012, 10:08 PM   #6
diyAudio Member
 
Join Date: Aug 2012
Yup, I just heard from the guy. The inductor bouncing around inside the amp is a new problem.. so it mustve shorted and gotten hot enough to melt the solder and fall off. Wow.


Okay, so if thats what happened.. why does it typically happen? Is it fixable?
  Reply With Quote
Old 21st August 2012, 01:00 AM   #7
diyAudio Member
 
Join Date: Dec 2005
Location: Northern California
I have seen inductors break there connections to the board before but usually its just one of the connections not all of them, and usually its due to excessive shock and vibration.
In this case yours would have four connections if its the toroid filter for both rails, they have two ins and two outs. They short due to lose windings and the insulation scuffs off the wires and they short against each other or the core itself. Either way its a rewind or replace to repair in most cases. If your lucky you might find the short and be able to clear it with some simple insulating materials. But this is only sometimes.
A Ebay seller had dozens of these old boards he was selling and Patrick of robotunderground on Ebay bought them all. So maybe he can sell you spare parts since these are custom designed for each amp and are a manufacturer only part. Its either that or try to save the toroid to rewind to spec.

The toroid issue might end up be the hardest to deal with due to lack of available parts and design info from the manufacturer. The amp might run without the filter but its was there most likely for design reasons to improve power supply noise issues and overall SQ of the amp.

Without pictures of the amp we are all dealing with arbitrary ideas here, and basically just guessing as to what is really going on with your parts only amp buys. You might want to hold off on buying into unknowns like this especially since your relying on others to be able to repair these unknown issues.

Oh for the toroid to have melted off the board the board would likely be so damaged as to not be able to repair the board let alone the toroid. You really need pictures of what you getting into before this becomes a money sink of no returns. Caveat Emptor < buyer beware >
  Reply With Quote
Old 21st August 2012, 05:20 AM   #8
diyAudio Member
 
Join Date: Aug 2012
Click the image to open in full size.

Here is a picture of the amp thats missing the inductor and the 2 caps. I know that doesnt do much good.. but I dont have it on hand.

I have found a total of 4 Diamond D7 amps that need repair. 2 D7104s, a D7152, and a D7402.
  Reply With Quote
Old 21st August 2012, 07:15 AM   #9
diyAudio Member
 
Join Date: Apr 2011
Location: Anchorage AK
saw those amps, but not impressed on the price. i wrote the one missing the inductor and caps off as being unsuccessfully messed with, not that anything has fallen out. might believe the cap would break off from extreme vibration, but not the inductor. wondering if he still even has the inductor. kind of hard to re-wrap thin air
  Reply With Quote
Old 21st August 2012, 06:31 PM   #10
diyAudio Member
 
Join Date: Dec 2005
Location: Northern California
Ok I see that one of the mylar input caps for one of the channels is missing. See the large metal rack in the middle there are supposed to be four of those large rectangular mylar caps there, one is missing. no biggy there but it does need to be replaced.

As for the two missing rail caps, I am not sure as my memory is faded now about these but it would not hurt to replace all of those and include two extras to fill the empty spaces.

The large toroid I was talking about is in plain site between those caps. So what ever is broken off and bouncing around inside is probably not a toroid as this amp only had two of them and I see both of them in the picture where they belong. The larger one in between the caps is the big failure item I saw on all of those boards that were sold on ebay a couple years ago now.

So thanks for the picture it helps bunches. But what I see does not match your description in a few places. This amp is fairly old now so cap replacement is not too unexpected with age and use. The missing Mylar in the middle is likely the part bouncing around inside the amp and they are fairly common to come by since PPI used the same cap in their amps. in fact I was once told that these amps were designed by X PPI engineers after PPI went under so similarities will exist between the two different amps.

I can't attest to its repair-ability as I am not the tech working on it but your EE buddy might find it feasible to bring her back to life for reasonable efforts and moneys. ...hope some of this is useful and helpful...
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Diamond Amp TimS Solid State 10 4th October 2012 06:15 AM
Diamond buffer pdul Solid State 23 5th February 2012 03:06 PM
DIAMOND D7402 ALPINE AJ Car Audio 2 8th September 2011 12:20 AM
MiniWatt N3 problems, oscillation thumping and RF/motor problems. Destroyer OS. Tubes / Valves 18 6th July 2010 12:14 AM
Diamond buffers Nordic Parts 7 13th March 2007 02:13 PM


New To Site? Need Help?

All times are GMT. The time now is 07:21 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2