Page 1 of 2 1 2 LastLast
Results 1 to 10 of 13

Thread: trying to bring this back to life

  1. #1
    Join Date
    Jan 2020
    Posts
    6
    Thanks
    4
    Thanked 2 Times in 2 Posts
    Rep Power
    0

    trying to bring this back to life

    Sign in to disable this ad
    Hi all, bought this Fostex XR-3 of ebay and like a muppet inserted a wrong power adapter and it started to smoke...as you do...
    I think I found what burned so just wondering if I replace this resistor looking thing if it would power up, I couldn't see any further damage but could there be more than meets the eye? and can anyone identify the (d603) part?
    I had a quick look on the internet but couldn't find it.
    Thanks
    Attached Thumbnails Attached Thumbnails 2-jpg  

  2. #2
    Join Date
    Jun 2006
    Location
    Austin, Texas
    Posts
    14,456
    Thanks
    63
    Thanked 613 Times in 560 Posts
    Rep Power
    21474864
    that would be a diode. It's the right size and the "D" in D603 means Diode.

    Cannot tell the value. I'm guessing if it smoked, it might have protected the rest of the circuitry. Not that that it's job, but just because it was the first to die.

  3. The Following User Says Thank You to Chili For This Useful Post:


  4. #3
    Join Date
    Aug 2005
    Location
    U.K.
    Age
    34
    Posts
    19,559
    Thanks
    1,221
    Thanked 1,042 Times in 920 Posts
    Rep Power
    1000000
    There's two ways to look at a blown component.
    One is it's blown : If I replaced it it's fixed.
    The other is it's blown : Something cause it to blow. If I replace it then new one will blow too!

    Depending on your comfort and skill you might want to get a hold of a schematic and find out where that diode is in the circuit and what it's doing before replacing.
    ---------- Steenaudio Website ----------

  5. The Following User Says Thank You to Steenamaroo For This Useful Post:


  6. #4
    Join Date
    Nov 2012
    Posts
    2,826
    Thanks
    12
    Thanked 322 Times in 289 Posts
    Rep Power
    5771717
    Quote Originally Posted by Chili View Post
    Not that that it's job, but just because it was the first to die.
    On the contrary, that really IS it's job. It is ostensibly a "reverse polarity protection" diode. Generally, these are not actually meant to protect the circuit, though. What they actually protect is the company from having to fulfill warranty claims when you use anything other than their approved power supply. It sort of protects the circuit by acting as a short circuit to stop the reversed power affecting other components, but only until it heats up and explodes. Once that happens, unless you get lucky and it destroys the traces that would get power to past it, everything else will just fry also.

    Honestly, if it was only that diode that was damaged, you should be able to just remove it, use the correct power supply, and it should work. Like, it's not really necessary for normal operation. BUT I've never known that to be true. Every time I've ever seen this type of diode explode (usually in guitar pedals) the thing never worked again. You might not necessarily see anything that looks damaged, but it's pretty likely to have popped some of the other semiconductors in there somewhere.

  7. The Following User Says Thank You to ashcat_lt For This Useful Post:


  8. #5
    Join Date
    Jan 2020
    Posts
    6
    Thanks
    4
    Thanked 2 Times in 2 Posts
    Rep Power
    0
    I contacted a supplier earlier and the d603 is apparently the position on the circuit diagram and not the diode ID number as I originally thought. They require the voltage and the current rating in order to find a suitable alternative.

    Btw I've also found the adapter I was "supposed" to use but I'll think I'll wait a bit see if I can get hold of the diode first before I use it as it's correct dc and voltage but not original.

  9. #6
    Join Date
    Nov 2012
    Posts
    2,826
    Thanks
    12
    Thanked 322 Times in 289 Posts
    Rep Power
    5771717
    Naw they don’t know what they’re talking about. It’s a power rectifier diode probably 1N4001 or similar. The voltage doesn’t much matter because it’s meant to be reverse biased anyway and any of that class of diodes will be fine with any sane DC wallwart . It’s not supposed to flow any current in normal use, and if it is conducting, the current will quickly approach infinity. Bigger would give you a better chance to avoid the explosion and actually protect your gear in future, but either way the V and A would be at most whatever the PSU is rated for.

    The fun part about all of this is that there is an easy way to use that part to actually protect the circuit from both reverse polarity DC and AC (which is wrong polarity half the time) without exploding, but nobody ever builds their gear that way because again it’s about catching you using the wrong polarity supply and voiding your warranty claim.

  10. The Following User Says Thank You to ashcat_lt For This Useful Post:


  11. #7
    Join Date
    Jan 2020
    Posts
    6
    Thanks
    4
    Thanked 2 Times in 2 Posts
    Rep Power
    0
    Wow, they've caught me alright just about a couple dozen years too late. Thanks for the diode info man, needed that.

  12. #8
    Join Date
    Sep 2008
    Location
    NW USA
    Posts
    1,573
    Thanks
    10
    Thanked 6 Times in 6 Posts
    Rep Power
    1686109
    Do you have a schematic? And what PSU did you use vs what you were supposed to use? It seems more likely something else failed causing that diode to fail.

  13. #9
    Join Date
    Jan 2020
    Posts
    6
    Thanks
    4
    Thanked 2 Times in 2 Posts
    Rep Power
    0
    I had the correct psu in terms of power just used the wrong one, anyway I soldered the 1N4001 diode I got off ebay and it's working fine now (with the correct psu this time). Result, thanks guys.

  14. The Following User Says Thank You to dbas For This Useful Post:


  15. #10
    Join Date
    Jun 2006
    Location
    Austin, Texas
    Posts
    14,456
    Thanks
    63
    Thanked 613 Times in 560 Posts
    Rep Power
    21474864
    Awesome. And thanks to ashcat for the great advice!!!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. How to bring to life my sampled Piano Solo?
    By sergeidave in forum Mixing Techniques
    Replies: 15
    Last Post: 03-14-2017, 06:24
  2. How do I bring these guitars to life?
    By Ex3vious in forum MP3 Mixing Clinic
    Replies: 15
    Last Post: 07-06-2015, 12:06
  3. Replies: 22
    Last Post: 01-26-2005, 22:04
  4. Help me bring my VS840 back to life
    By OneRoomStudios in forum Roland, Boss, VS Series Forum
    Replies: 5
    Last Post: 08-24-2004, 17:13

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •