+ Post New Thread
Results 1 to 6 of 6
AV and Multimedia Related Thread, Guitar amp. Circuit board wizard needed! in Technical; Hi All, Need some help! TL;DR goto end.... My elderly next door neighbour collared me the other day and asked ...
  1. #1
    Koldov's Avatar
    Join Date
    May 2011
    Location
    Bedfordshire
    Posts
    524
    Thank Post
    102
    Thanked 55 Times in 48 Posts
    Rep Power
    40

    Guitar amp. Circuit board wizard needed!

    Hi All,

    Need some help! TL;DR goto end....

    My elderly next door neighbour collared me the other day and asked me if I still played guitar. I told her that I did, but not much due to family and work stuff. Anyway, she proceeded to tell me about how her son had met a woman last year and gone to Estonia or something, he was playing in a band over there but had left a lot of amps in her garage (he's a bit of a musician, rocker, uni student type).

    She said she couldn't put her car in her garage and would like to with the weather and all. She said her son didn't want to/couldn't deal with the amps, didn't know if/when he would be back and to get rid of them/sell them if she wanted. She had taken a couple to the dump(!), but couldn't lift them and she only has a small car, also she didn't want to deal with ebay, newspaper ads etc.

    Anyway, she asked me if I wanted them... Well as a musician/hoarder/geek I couldn't say no and I knew I'd be helping her out. So, I pulled up my car and opened the boot, expecting a couple of old practice amps or similar. She looked at me shaking her head and said 'maybe you'd better see them first' and when she opened the garage door I was lost for words...

    All down one whole side of the garage was amps, speaker cabinets and head units, but there's the problem... It was wet, cold and damp in there (with some beastly spiders!) they had been in there a long time and that is no good for delicate electronics!

    One in particular caught my eye, it's a Carlsboro GLX-85 Special Edition (actually not that special by all accounts and not worth a great deal) so I thought I'd take that in to the house clean it up, dry it out and give it a blast! I thought I could even donate it to the school if it was any good. Unfortunately I was disappointed, it sounded horrible the controls were scratchy, I couldn't turn off the distorted sound and had loads of drop-outs, it sounded like the sound was struggling to come out then blasted at full volume...

    TL;DR

    However, I have taken it apart like a good geek and found nothing really amiss, apart from two components marked W22 R33 5% on the rear circuit board and they looked corroded. I have attached pictures, but I don't know what they are, where to get them from and how easy they are to replace. I looked a little on the net, but didn't find anything that looked the same. I don't have any circuit board/component level soldering experience, but I don't think the amp is worth the money to have it professionally repaired... Also, if I do change these it might not solve the problem, but if I try I might make it worse or destroy it completely! HELP!

    W22_R33_1.bmp

    Kol.

  2. #2

    plexer's Avatar
    Join Date
    Dec 2005
    Location
    Norfolk
    Posts
    13,232
    Thank Post
    667
    Thanked 1,638 Times in 1,463 Posts
    Rep Power
    423

  3. Thanks to plexer from:

    Koldov (25th February 2014)

  4. #3

    Join Date
    Dec 2013
    Posts
    100
    Thank Post
    0
    Thanked 15 Times in 12 Posts
    Rep Power
    37
    Quote Originally Posted by Koldov View Post
    Hi All,




    One in particular caught my eye, it's a Carlsboro GLX-85 Special Edition (actually not that special by all accounts and not worth a great deal) so I thought I'd take that in to the house clean it up, dry it out and give it a blast! I thought I could even donate it to the school if it was any good. Unfortunately I was disappointed, it sounded horrible the controls were scratchy,
    Get yourself a can of Fospro switch cleaner and give the control pots a good soak in it whilst wiggling the controls around. Dont use wd40 or similar as it tends to dissolve the carbon surfaces!

  5. Thanks to Nibiru from:

    Koldov (25th February 2014)

  6. #4

    Join Date
    Jun 2008
    Location
    leicester
    Posts
    713
    Thank Post
    73
    Thanked 171 Times in 148 Posts
    Rep Power
    53
    Check for bulging/leaking caps also.

  7. Thanks to difinity from:

    Koldov (25th February 2014)

  8. #5
    Koldov's Avatar
    Join Date
    May 2011
    Location
    Bedfordshire
    Posts
    524
    Thank Post
    102
    Thanked 55 Times in 48 Posts
    Rep Power
    40
    Yeah, I saw those ones based on the W22 & R33 markings. My concerns (knowing nothing about them) was about what they meant and if the other markings were pertinent, like the 5% bit or the online ones being 7W or JI...

    Quote Originally Posted by Nibiru View Post
    Get yourself a can of Fospro switch cleaner and give the control pots a good soak in it whilst wiggling the controls around. Dont use wd40 or similar as it tends to dissolve the carbon surfaces!
    Thanks I have a bottle of Servisol Super 10 that I normally use, same type of stuff I think. It's about the only maintenance I can do!

    Quote Originally Posted by difinity View Post
    Check for bulging/leaking caps also.
    Yup, good call on any circuit board (couldn't see any). In fact it looks pretty mint inside except for these two resistors...

    Kol.

  9. #6

    Join Date
    Nov 2010
    Posts
    452
    Thank Post
    59
    Thanked 69 Times in 59 Posts
    Rep Power
    34
    That component is a 0.33 ohm resistor and is unlikely to be the cause of your audio problems. Try to clean / replace the potentiometers and as others have said, check for bulging capacitors.

SHARE:
+ Post New Thread

Similar Threads

  1. [Website] Printing circuit boards
    By plexer in forum Jokes/Interweb Things
    Replies: 3
    Last Post: 19th November 2013, 10:57 AM
  2. RM Class Board driver needed
    By kirchie in forum Hardware
    Replies: 2
    Last Post: 15th November 2012, 11:46 AM
  3. Changing small LEDs on circuit boards
    By link470 in forum Hardware
    Replies: 15
    Last Post: 7th April 2012, 06:25 PM
  4. Quotes needed: Smart Board
    By BatchFile in forum Our Advertisers
    Replies: 4
    Last Post: 1st October 2009, 02:05 PM
  5. Smartboard Circuit boards
    By timbo343 in forum Hardware
    Replies: 12
    Last Post: 15th January 2009, 09:06 AM

Thread Information

Users Browsing this Thread

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

Posting Permissions

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