PCB repair for Radio Location device

alexchien

Member
Hi

I have a small PCB from a radio location device and I've shorted it out, thus it requires some new IC components replacing.
I can get the parts, but my soldering skills aren't quite up to it, neither do i have a de-solder tool.

An oscilloscope for testing the device may also be useful.

Would anyone in the Northern region be able to assist ? PM if so.

Thanks
 

Stuart France

Active member
I'll solder it for you if you can't get it done nearer home. I'm in South Wales and there's this thing called the Post Office.

As to removing solder, some general advice: don't ever use one of those spring-loaded suction pump thingies as it is not likely to remove enough of the solder and it risks damaging the PCB in the process. The stuff to use is the thin fine copper braid sold for desoldering purposes, which you apply with your ordinary hot soldering iron and the melted solder is wicked away in a couple of seconds.

If the PCB is double-sided with plated-though holes then use a higher iron temperature (up to a point) so as to wick out the solder from inside the hole too as well as what's on the pad. I put a tiny blob of solder on the end of the iron before applying the braid to the pad as this conducts heat quickly on to the PCB and initates the wicking process as the blob is wicked into the braid along with what you targetted for removal.

Incidentally, why isn't there a fuse in the circuit as it is a high power device and/or reverse polarity protection for any external battery?
 

Tangent_tracker

Active member
I'll solder it for you if you can't get it done nearer home. I'm in South Wales and there's this thing called the Post Office.

As to removing solder, some general advice: don't ever use one of those spring-loaded suction pump thingies as it is not likely to remove enough of the solder and it risks damaging the PCB in the process. The stuff to use is the thin fine copper braid sold for desoldering purposes, which you apply with your ordinary hot soldering iron and the melted solder is wicked away in a couple of seconds.

If the PCB is double-sided with plated-though holes then use a higher iron temperature (up to a point) so as to wick out the solder from inside the hole too as well as what's on the pad. I put a tiny blob of solder on the end of the iron before applying the braid to the pad as this conducts heat quickly on to the PCB and initates the wicking process as the blob is wicked into the braid along with what you targetted for removal.

Incidentally, why isn't there a fuse in the circuit as it is a high power device and/or reverse polarity protection for any external battery?
Nothing wrong with sodler suckers, I use them all the time at work, along with solder wick. In fact the latter can cause issues with the amount of time required to hold on to plated through joints etc...

It's knowing when to use which type is the key!

One very good method, but expensive is to use ultra low melt solder for more awkward jobs, and then there is always a hot air source along with iron...
 

shotlighter

Active member
Nothing wrong with sodler suckers, I use them all the time at work, along with solder wick. In fact the latter can cause issues with the amount of time required to hold on to plated through joints etc...

It's knowing when to use which type is the key!

One very good method, but expensive is to use ultra low melt solder for more awkward jobs, and then there is always a hot air source along with iron...
Yep, seen no end of tracks pulled off with braid, by not applying enough heat, quickly enough, I'm a soldersucker man for nearly every thing & that's in a near 50 year career as a (mostly) field engineer. The only reason I've ever used braid, is for the odd bit SMT stuff - but my eyesight isn't up to that now.
 

Tangent_tracker

Active member
Yep, seen no end of tracks pulled off with braid, by not applying enough heat, quickly enough, I'm a soldersucker man for nearly every thing & that's in a near 50 year career as a (mostly) field engineer. The only reason I've ever used braid, is for the odd bit SMT stuff - but my eyesight isn't up to that now.
I use both tbh! They each have their advantages and braid can be hit and miss at times, just gotta make sure you get the heat flowing.... But yep especially in older equipment tracks do like to peel off at times! Just gotta be ready to fix it!
 
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