1. Forum
  2. Usenet
  3. SCI.ELECTRONICS.REPAIR

  • Re: The "Repair" - (was Re: Scope keeps blowing fuses)

    From Cursitor Doom@21:1/5 to All on Tue Oct 25 19:33:00 2022
    Here we go, gentlemen, the finished "repair" on the PSU board:

    Before (the faulty RIFAs are arrowed since they're a bit hard to spot) https://disk.yandex.com/i/9VID9SDCNLoxQw

    After (the new replacements are not arrowed, since they're blindingly
    obvious)
    https://disk.yandex.com/i/uHJW9u33lWACVQ


    It's just awful, isn't it?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From JC@21:1/5 to Cursitor Doom on Tue Oct 25 15:43:14 2022
    Cursitor Doom wrote:

    Here we go, gentlemen, the finished "repair" on the PSU board:

    Before (the faulty RIFAs are arrowed since they're a bit hard to spot) https://disk.yandex.com/i/9VID9SDCNLoxQw

    After (the new replacements are not arrowed, since they're blindingly obvious)
    https://disk.yandex.com/i/uHJW9u33lWACVQ


    It's just awful, isn't it?

    Probably won't fit back in the scope cos of the IEC filter.
    Tons of info out there on this power supply and how to fix:

    https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/150/

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeff Liebermann@21:1/5 to All on Tue Oct 25 12:42:51 2022
    On Tue, 25 Oct 2022 19:33:00 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    Here we go, gentlemen, the finished "repair" on the PSU board:

    Before (the faulty RIFAs are arrowed since they're a bit hard to spot) >https://disk.yandex.com/i/9VID9SDCNLoxQw

    After (the new replacements are not arrowed, since they're blindingly >obvious)
    https://disk.yandex.com/i/uHJW9u33lWACVQ


    It's just awful, isn't it?

    I've done worse. I don't like the exposed hot wires, but since you're
    the only person likely to be working on the scope, it's probably an
    acceptable risk.

    I suggest you tack the capacitors to the PCB with a little REMOVABLE
    glue, such as hot melt glue or non-acetic-acid RTV.

    --
    Jeff Liebermann jeffl@cruzio.com
    PO Box 272 http://www.LearnByDestroying.com
    Ben Lomond CA 95005-0272
    Skype: JeffLiebermann AE6KS 831-336-2558

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to All on Tue Oct 25 21:39:47 2022
    On Tue, 25 Oct 2022 15:43:14 -0400, JC <Chipbee40_SpamNo@yahoo.com>
    wrote:

    Cursitor Doom wrote:

    Here we go, gentlemen, the finished "repair" on the PSU board:

    Before (the faulty RIFAs are arrowed since they're a bit hard to spot)
    https://disk.yandex.com/i/9VID9SDCNLoxQw

    After (the new replacements are not arrowed, since they're blindingly
    obvious)
    https://disk.yandex.com/i/uHJW9u33lWACVQ


    It's just awful, isn't it?

    Probably won't fit back in the scope cos of the IEC filter.

    It does actually fit back in again - *just* about.

    Tons of info out there on this power supply and how to fix:

    https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/150/

    Many thanks for that indeed.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to All on Tue Oct 25 21:38:50 2022
    On Tue, 25 Oct 2022 12:42:51 -0700, Jeff Liebermann <jeffl@cruzio.com>
    wrote:

    On Tue, 25 Oct 2022 19:33:00 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    Here we go, gentlemen, the finished "repair" on the PSU board:

    Before (the faulty RIFAs are arrowed since they're a bit hard to spot) >>https://disk.yandex.com/i/9VID9SDCNLoxQw

    After (the new replacements are not arrowed, since they're blindingly >>obvious)
    https://disk.yandex.com/i/uHJW9u33lWACVQ


    It's just awful, isn't it?

    I've done worse. I don't like the exposed hot wires, but since you're
    the only person likely to be working on the scope, it's probably an >acceptable risk.

    Thanks, Jeff, I thought you'd tear me a new arsehole!

    I suggest you tack the capacitors to the PCB with a little REMOVABLE
    glue, such as hot melt glue or non-acetic-acid RTV.

    In an ideal world and all that. Sadly, we both know that's not going
    to happen, Jeff. :-(

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to All on Wed Oct 26 08:34:06 2022
    On Tue, 25 Oct 2022 19:33:00 +0100, Cursitor Doom <cd@notformail.com>
    wrote:


    Here we go, gentlemen, the finished "repair" on the PSU board:

    Before (the faulty RIFAs are arrowed since they're a bit hard to spot) >https://disk.yandex.com/i/9VID9SDCNLoxQw

    After (the new replacements are not arrowed, since they're blindingly >obvious)
    https://disk.yandex.com/i/uHJW9u33lWACVQ


    It's just awful, isn't it?

    You could probably have leadformed the new parts to suit.

    My guess is you just prefered to solder from the comp
    side.

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to legg on Wed Oct 26 16:15:00 2022
    On Wed, 26 Oct 2022 08:34:06 -0400, legg <legg@nospam.magma.ca> wrote:

    On Tue, 25 Oct 2022 19:33:00 +0100, Cursitor Doom <cd@notformail.com>
    wrote:


    Here we go, gentlemen, the finished "repair" on the PSU board:

    Before (the faulty RIFAs are arrowed since they're a bit hard to spot) >>https://disk.yandex.com/i/9VID9SDCNLoxQw

    After (the new replacements are not arrowed, since they're blindingly >>obvious)
    https://disk.yandex.com/i/uHJW9u33lWACVQ


    It's just awful, isn't it?

    You could probably have leadformed the new parts to suit.

    My guess is you just prefered to solder from the comp
    side.

    RL

    It's really not my thing. When people say, "Just recap anything
    suspect" and there might be fewer than half a dozen to do, the
    prospect still fills me with horror. If they only knew how ironic the
    "Just" bit strikes me in suggestions like that.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Peter W.@21:1/5 to All on Wed Oct 26 08:57:56 2022
    That would be Viking....

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to peterwieck33@gmail.com on Wed Oct 26 22:18:44 2022
    On Wed, 26 Oct 2022 08:57:06 -0700 (PDT), "Peter W."
    <peterwieck33@gmail.com> wrote:

    It's really not my thing. When people say, "Just recap anything
    suspect" and there might be fewer than half a dozen to do, the
    prospect still fills me with horror. If they only knew how ironic the
    "Just" bit strikes me in suggestions like that.

    The problem with vintage equipment, however well designed and well built, is that parts within it age. Typically, items that are approaching, or exceeding 30 years old will have some marginal parts within. Further, if those parts are 'common' as in "
    many of them", if one fails the others will not be far behind. Some truisms:

    a) As in the Holland America commercials - Time is a precious commodity.
    b) Most (not all) hobbyists are not limited by cost constraints for a few parts. So, a US$20-or-equivalent investment to save a valuable item is not outrageous.
    c) Most of the effort in repairs is 'getting to it' - the taking-apart, the testing, documenting, and then reassembly.
    d) The actual repairs take very little time.

    "The actual repairs take very little time."

    If you only knew the irony of that statement when the task is
    completeed by someone with my eyesight and fine motor skills.

    As to soldering and technique - time and repetition will give you more confidence.

    No it won't. I've been doing this for more than 50 years and I'm still
    every bit as shit at it as I was half a century ago. I have not
    improved one iota and only a damn fool would believe the future's
    going to be any better than the past with a skill set like mine.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Tony Stewart@21:1/5 to All on Tue Nov 1 01:46:59 2022
    The key to faster resolution of fusing faults is test method for fault isolation.

    Possible methods include:

    1. Input voltage attenuation below fault threshold and probe test points.

    2. isolate secondary sections by disconnect

    3. Check for thermal hotspots safely.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)