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Newbie seeking advice...

C

Chris Tarling

Yellow Hound
I am in the process of acquiring a pair of Meridian M2 loudspeakers.
They are apparently in fine working order, but look rather tatty.
My intention is to refurbish them as a winter project, i.e. re-veneer the cabinets and refurbish the electronics.

Now I have never delved into PCB component replacement. I've been quoted £425 to re-cap the pair of amplifiers in the speakers.

Now on the face of it this seems like quite a simple process, but nevertheless something I have not attempted before. But I'm reasonably capable and have the time to take it slow & steady.

I'm looking for advice as to what kit I need (I have a soldering iron but not sure if it is the best type for the process), tips for going about the work, on-line resources I can read, what components to go for...

So basically any advice on completing this task!

Thanks in advance!
 
I don't know the amps personally, but here http://www.meridian-audio.info/show.php?compid=32 has a couple of pictures of the amp boards and it is clear that there are a couple of large PSU caps (the horizontal ones by the transformer) and a number of smaller caps on the boards.

If you take a few clear pictures on the boards and post them here I'm sure there will be plenty of people willing to help. :)

Personally I use a 25W soldering iron, Antex XS25, with a 3mm tip and some de-soldering braid. Have a look at this video to see how to use both.

 
DuncanF said:
Ridiculous! I recapped some M3s for a friend recently and the component cost was c. £50, plus an hour or two of my time.
Click to expand...

One of the reasons why I thought I would learn how to do this myself. Learn a new skill, save a heap of money I can't afford to spend and hopefully refresh the M2s to last a good few years yet.
 
Only other thing I can add is solder wick doesn't work for me. With through hole components I just solder sucker most of the solder off, add a tiny bit of fresh flux core solder and heat each leg alternately, wiggling a little as you go to walk it out. For snap in caps that require a bit more oomph, just add a little solder and use the same technique, but wiggle / walk it out only a little at a time as you will damage the tracks if not very careful. Also, don't force it, let the heat do the work.
 
a.palfreyman said:
Get an old piece of kit that is either broken or surplus to practice on. Desolder, remove and refit the old capacitors. Nothing beats a bit of practice.
Click to expand...
Or even replace them with some random (cheap, unbranded !) new capacitors of about the right size.

BugBear
 
It's not rocket science!

"Practice" on the real thing and then it's done!

Take care not to bridge any adjacent pcb tracks with a big blob of solder.

Just be sure to get the polarity if the capacitors the right way round. You have the advantage of having 2 identical items so do them one at a time and refer to the other unit if you find yourself wondering "which way round does that go?)!
 
a.palfreyman said:
Only other thing I can add is solder wick doesn't work for me. With through hole components I just solder sucker most of the solder off, add a tiny bit of fresh flux core solder and heat each leg alternately, wiggling a little as you go to walk it out. For snap in caps that require a bit more oomph, just add a little solder and use the same technique, but wiggle / walk it out only a little at a time as you will damage the tracks if not very careful. Also, don't force it, let the heat do the work.
Click to expand...

Thank god, thought it was just me, I have never got solder wick to work.
 
I find that desolder braid works fine if you add a touch of resin cored solder to the joint as if you're soldering it rather than de-soldering it. The flux helps wet the braid allowing it to be wicked up the braid.
 
I could never get desoldering braid to work either.

If I could go back in time I wouldn't have bothered messing about with solder suckers (I've been through loads) I'd have just splashed out on the Duratool desoldering station I have now.
It's so much quicker and easier, there's also a lot less risk of damaging the board and it's not even that expensive.
 
Fatmarley said:
I could never get desoldering braid to work either.

If I could go back in time I wouldn't have bothered messing about with solder suckers (I've been through loads) I'd have just splashed out on the Duratool desoldering station I have now.
It's so much quicker and easier, there's also a lot less risk of damaging the board and it's not even that expensive.
Click to expand...

Umm seems a little like overkill for me but that desoldering station is tempting at £84 at CPC. I'm a sucker for tools...
 
I'll admit that I've struggled with solder wick as well. Occasionally it's worked like magic, but most of the time it's utterly useless and frustrating. I'm not sure why it works so well when it does. I tend to leave my iron at 700deg, and I think I used the same technique each time. Does anyone have any suggestions (or a video that perfectly encapsulates the best practice)?
 
Last edited:
Knew I'd seen this somewhere, copied from another thread:
martin clark said:
... use a bloody big iron, 30w or so, to ensure the puddle you are wanting to shift is fully molten first and quickly - what kills parts, and solder-suckers, is an undersized/under-powered iron held there 'forever' to get things moving. it will also lift tracks. you can solder ssop parts with a 30w iron in an instant..no harm done...
Click to expand...
 
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