Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss

Removing defective switch from PCB

56 views
Skip to first unread message

bitrex

unread,
May 17, 2017, 9:02:59 AM5/17/17
to
I have a Behringer EQ that has a bad front panel switch. It looks to be
a standard 3 pin SPDT type, surrounded by a metal bracket that holds it
fast to the PCB.

I've been having a lot of difficulty removing it from this PCB with
plated-through holes for replacement; it's resisted all my attempts to
pry it out using an iron/solder sucker or solder wick. I don't own a hot
air station unfortunately - any tips here?

tabb...@gmail.com

unread,
May 17, 2017, 9:25:36 AM5/17/17
to
With PTH you need to get lots of heat into the board - removing solder achieves the opposite. Put the sucker & braid away and solder it, then you can heat one pin at a time and bend the board ever so slightly, and slowly walk it out. Yes, it's slow. No, you mustn't overheat anything.


NT

ohg...@gmail.com

unread,
May 17, 2017, 9:33:02 AM5/17/17
to
Not a good plan IMO - if it's just a top and bottom conductor board, maybe. But if it's a multi layer I wouldn't try it. That kind of manipulation can cause a detachment of a middle layer conductor that would be tough to solve without a schematic or an identical board to trace out.

But you're correct about heat. When working on multi layer boards that require multiple through the hole pin extraction, I preheat the board to 125C and let it soak 15 minutes. Add some liquid flux and solder removal techniques are usually effective.

bitrex

unread,
May 17, 2017, 10:05:10 AM5/17/17
to
Thanks for the advice guys. I have a schematic available fortunately;
I'll have to take a closer look at the board but since it's Behringer my
guess is that a double-sided board at most heh heh ;-)

rickman

unread,
May 17, 2017, 10:31:58 AM5/17/17
to
Yeah, double sided is not so bad, but it can be hard to deal with the
triple sided ones. ;)

--

Rick C

Ralph Mowery

unread,
May 17, 2017, 10:37:29 AM5/17/17
to
In article <4SXSA.149693$Qa2....@fx10.iad>,
bit...@de.lete.earthlink.net says...
With the hot air rework stations from China at only $ 45 you may want to
look into getting one. While they probably will not hold up under heavy
usage, I have one and it works fine for hobby use. YOu get the hot air
gun and a soldering iron that heats up very fast.

Here is one from ebay..
122275067539

gghe...@gmail.com

unread,
May 17, 2017, 10:47:01 AM5/17/17
to
Any chance you can cut the pins with a pair of cutters, dremel grinding
wheel or some other butchery? That's what I do most times.
Divide and conquer.

George H.

John Robertson

unread,
May 17, 2017, 11:14:58 AM5/17/17
to
Item number is not valid...

John :-#(#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

Ralph Mowery

unread,
May 17, 2017, 11:43:40 AM5/17/17
to
In article <IY2dna3rrKlx9YHE...@giganews.com>,
sp...@flippers.com says...
>
> On 2017/05/17 7:37 AM, Ralph Mowery wrote:
> > In article <4SXSA.149693$Qa2....@fx10.iad>,
> > bit...@de.lete.earthlink.net says...
> >>
> >> I have a Behringer EQ that has a bad front panel switch. It looks to be
> >> a standard 3 pin SPDT type, surrounded by a metal bracket that holds it
> >> fast to the PCB.
> >>
> >> I've been having a lot of difficulty removing it from this PCB with
> >> plated-through holes for replacement; it's resisted all my attempts to
> >> pry it out using an iron/solder sucker or solder wick. I don't own a hot
> >> air station unfortunately - any tips here?
> >
> > With the hot air rework stations from China at only $ 45 you may want to
> > look into getting one. While they probably will not hold up under heavy
> > usage, I have one and it works fine for hobby use. YOu get the hot air
> > gun and a soldering iron that heats up very fast.
> >
> > Here is one from ebay..
> > 122275067539
> >
>
> Item number is not valid...
>
> John :-#(#

Works for me.

Try searching for

862D+ 2in1 SMD Solder Soldering Iron Hot Air Rework Station

There are many of them for just under $ 50.

N_Cook

unread,
May 17, 2017, 11:51:04 AM5/17/17
to
I don't know what this plate may be, can you Dremmel+.5mm grinding disc,
separate it from the switch and then desoldering?

pf...@aol.com

unread,
May 17, 2017, 1:07:04 PM5/17/17
to
On Wednesday, May 17, 2017 at 11:51:04 AM UTC-4, N_Cook wrote:

> I don't know what this plate may be, can you Dremmel+.5mm grinding disc,
> separate it from the switch and then desoldering?

Dremel
Grinding Disc
PC Boards
Thousands of tiny bits of metal

Does anyone else see a recipe for disaster here?

I keep one of these - which, despite its size, is very good at fine cuts, almost to the 'nibbling' level. And no swarf. Sharp, tough, cuts mild steel very easily.

https://www.channellock.com/data/default/images/catalog/original/E338-842_1-842.png

Peter Wieck
Melrose Park, PA

John Robertson

unread,
May 18, 2017, 7:33:45 PM5/18/17
to
Clear your cache. I get a No Listing for 122275067539.

John :-#)#

Chris Jones

unread,
May 18, 2017, 7:56:38 PM5/18/17
to
If you have a hardware store type hot air gun with closed-loop
temperature control then you may be able to use that. I recently had to
use one set to 340 deg C to get a connector off, and that was one pin at
a time. I needed the hot air gun again in one hand, to get the solder to
melting point to clean out the holes with one of those desoldering irons
in the other hand (with the vacuum pump). Even filling up the holes with
leaded solder only made it slightly easier, but I could still not get
some holes to melt right through with any soldering iron (including a
Metcal with a very large, very hot tip), even with the board on a hotplate.

rickman

unread,
May 18, 2017, 8:10:37 PM5/18/17
to
I found it by doing a Bing search on the number directly from your post.
(T-bird lets you do that)

--

Rick C

stra...@yahoo.com

unread,
May 18, 2017, 11:44:02 PM5/18/17
to
Rather than grind, I clip all the pins and extract one at a time. It depends if you're trying to salvage the part or just want minimum damage to the board.

When removing caps from computer mother boards I sometimes have to use a hot air tool in one hand and a Metcal iron in the other for the ground pins with no thermal relief on the internal pads. My hot air tool is one of those 862D units. I use only the air part which is also an excellent heat shrink tool.


John Robertson

unread,
May 19, 2017, 2:33:03 AM5/19/17
to
Usually if you drop the item number into the search bar on eBay it pops
up with the item listing. I am so used to doing that that I did not try
any other method...so I tried google and indeed, up popped the hot air
station.

Thanks for reminding me to dig deeper, and watch assumptions!

Jon Elson

unread,
May 20, 2017, 12:10:17 AM5/20/17
to
One possible way is to break the switch apart, so that you can remove each
pin separately. The metal housing might need to be sawed or filed until the
mounting pins are separated, then pluck each with tweezers while heating
with soldering iron. Then, break the plastic parts and extract the contacts
the same way. This may be the best way to avoid damaging the board.

Jon
0 new messages