Hi everyone...
Wish you okay and healthy... 😀
Today(2nd Feb 2017), i am still far away from home cause my cousin "pull" me here and "pushing" me for little vacation about 6 days
He has same hobbies with me, especially electronica
Here this myth started...
Last night, his neighboor calling us for servicing his amplifier
He has 8 amplifier units(2 units 2500 watt stereo Blazer, 2 units APEX 2500 watt sterep and 4 units 450 watt OCL stereo) cause he has audio amplifier rent for ceremony like wedding, event etc
His units never been checked and modified from the first time he buy it, almost 1,5 year
So he feels if there are many people will renting them, he thinks those amplifiers needed some little service
After opening them one buy one, my cousin starting checking everything
After the result is okay, he warming up his solder but i am surprised cause nothing broken nothing wrong nothing modification also no one needed component replacement
He talks to me "looks like every components needed re-soldering also re-bolding voltage rail and speaker output cause it will make those amplifier will have more durability"
I guess he is right then he said, not only audio devices but almost all every electronic devices needed re-soldering like TV, radio, DVD, home theater, LED bulb lamps and many more
But he said, before re-soldering please make sure your tools is complete like SMD solder and make sure or double check some components can be re-soldering or not cause some components have limit solder heat
This is my question...
Is that true, the myth about re-soldering and re-bolding pcb line for electronic devices will give those devices better current flowing and will have more extra durability???
😕 😕 😕
Wish you okay and healthy... 😀
Today(2nd Feb 2017), i am still far away from home cause my cousin "pull" me here and "pushing" me for little vacation about 6 days
He has same hobbies with me, especially electronica
Here this myth started...
Last night, his neighboor calling us for servicing his amplifier
He has 8 amplifier units(2 units 2500 watt stereo Blazer, 2 units APEX 2500 watt sterep and 4 units 450 watt OCL stereo) cause he has audio amplifier rent for ceremony like wedding, event etc
His units never been checked and modified from the first time he buy it, almost 1,5 year
So he feels if there are many people will renting them, he thinks those amplifiers needed some little service
After opening them one buy one, my cousin starting checking everything
After the result is okay, he warming up his solder but i am surprised cause nothing broken nothing wrong nothing modification also no one needed component replacement
He talks to me "looks like every components needed re-soldering also re-bolding voltage rail and speaker output cause it will make those amplifier will have more durability"
I guess he is right then he said, not only audio devices but almost all every electronic devices needed re-soldering like TV, radio, DVD, home theater, LED bulb lamps and many more
But he said, before re-soldering please make sure your tools is complete like SMD solder and make sure or double check some components can be re-soldering or not cause some components have limit solder heat
This is my question...
Is that true, the myth about re-soldering and re-bolding pcb line for electronic devices will give those devices better current flowing and will have more extra durability???
😕 😕 😕
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more likely reducing durability
is your cousin smarter than all of the EE, Industrial Engineers that designed the product and controlled the manufacturing process?
if the solder joint wasn't cracked/broken then it should be fine and left alone
the heat stress can change some component's values or even break them
today with lead free solders you risk seriously messing up the metallurgy of the joint if you add any different mix of elements from the required solder film wetting your iron
PCB copper is about 10x better electrical conductivity than most solders, and few circuits actually care about trace resistance within orders of magnitude
if the circuit is limited by trace conductance the EE responsible should have used the right trace thickness and width already
is your cousin smarter than all of the EE, Industrial Engineers that designed the product and controlled the manufacturing process?
if the solder joint wasn't cracked/broken then it should be fine and left alone
the heat stress can change some component's values or even break them
today with lead free solders you risk seriously messing up the metallurgy of the joint if you add any different mix of elements from the required solder film wetting your iron
PCB copper is about 10x better electrical conductivity than most solders, and few circuits actually care about trace resistance within orders of magnitude
if the circuit is limited by trace conductance the EE responsible should have used the right trace thickness and width already
I agree.
Reheating all the components to soldering temperature is likely to overstress at least a few and could lead to a premature failure.
Mixing lead free and leaded solders is a crap shoot. I have no idea what that does to reliability.
Leave alone.
A good clean to remove years of dust and dirt and grease will do more good than all that heating.
Check connectors for cracked or broken insulators and bent or de-formed pins.
If you have access to some measuring equipment then check against the manufacturers specification.
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Yes, "reflowing" is a good way to reduce reliability yet it is surprisingly popular amongst people who don't understand electronics yet have learnt to solder.
Bad joints need remaking, not reflowing, after careful fault tracing. Good joints should be left alone.
Does your friend make a lot of money from doing unnecessary work on electronics owned by gullible people?
Bad joints need remaking, not reflowing, after careful fault tracing. Good joints should be left alone.
Does your friend make a lot of money from doing unnecessary work on electronics owned by gullible people?
not...
he said, he knows what he doing
his terms and conditions for re-soldering is that devices have age more than 3 years
also re-soldering is not good enough for his pocket cause costing more dollars
so re-soldering is only hoax and not good for PCB itself and can making cooper plate broken
the worst case is making the devices see its death
Back in the latter part of last century ( i.e late '80s / early 90's) I worked as a service department paper pusher for a local hifi shop. This was of course years before surface mount, and lead-free solder were even a pipe-dream, and with certain products . models it was standard practice to reflow all the PCB solder joints on power supply components, and selector switches / pots, as well a thorough spraying of the latter with contact cleaner/washer whenever the symptoms were "sporadic loss/drop outs" or "start-up / power down" farts.
It actually often "worked" , and was seldom rejected on manufacturer's warranty claims. Of course enough of our customer base were pliant passengers on the merry-go-round/ constant upgrade path that by the time symptoms recurred or worsened, it become someone else's problem. Hell, that describes myself at the time - but of course, I've matured since then 😛
It actually often "worked" , and was seldom rejected on manufacturer's warranty claims. Of course enough of our customer base were pliant passengers on the merry-go-round/ constant upgrade path that by the time symptoms recurred or worsened, it become someone else's problem. Hell, that describes myself at the time - but of course, I've matured since then 😛
In the early to mid 70's, a lot of (through-hole) circuit boards were made by stuffing the leads through and just floating the board across a bath of solder. The connection quality and strength was often pretty poor. When I was doing service around then, it was customary to look over all the connections, not because they were "old", but because some may have broken loose if the board ever were flexed or heavy components got rocked around during transport. That would sometimes fix the problems.
well...
from your words, i can take simple conclusion...
better technology better metallurgy affected our technique for the best PCB line
maybe it worked about 60's till 70's but now it will make our devices retired soon as possible
alright, this myth affected for people who have been feeling 60's till 70's cause our technology is still in the developmental process
i can see, many electronic devices is so big and some looks like giant at 60's 70's
and many scientist still looking for the better metallurgy pattern
but now with many developments of our electronic devices, re-soldering re-bolding PCB line will make us costing more money
I haven't seen much of anything that's newer and had bad solder joints. Well except some eBay specials direct from China, some of them have been questionable.
But I've had good experiences mixing Kester 44 to lead free solder. Usually I'm just removing the part, and the 44 allows this to happen without damage from heat, because lead free takes an annoying amount once it has been used the first time. Then I clean and solder it with 44 and all is well. Lead is better long term than lead free because it never grows nickel wiskers from what I've read.
But I've had good experiences mixing Kester 44 to lead free solder. Usually I'm just removing the part, and the 44 allows this to happen without damage from heat, because lead free takes an annoying amount once it has been used the first time. Then I clean and solder it with 44 and all is well. Lead is better long term than lead free because it never grows nickel wiskers from what I've read.
you could do it that...
but for me and most of electronic people in my country, that's so hard
even we are so easy for buying on line
but first time it comes my country, our customs is ready for scanning and will make us costing more money...
that's why here, we only buying solder wire per roll and that's only 1,5 US dollars(small), 4 dollars US(med), 7 US dollars(big) and jumbo roll for 11 US dollars
but the worst is, we never known what exactly the type of this solder wire...
cause those seller selling it with their own label...
I've seen some older equipment that needed some joints reflowed. Once a bad solder joint in a large amplifier had caused a catastrophic failure. I've seen components that weren't even soldered to the board any more; you could just yank them right off the board. But - in general I would not recommend a complete reflow of a board.
However my buddy, who knows zip about electronics, read on the internet that you could restore the function of an ABS module on his truck by reflowing the solder joints. A new module was like $700 so he figured he had nothing to lose. He did not consult with me. He just opened up the module and reflowed every joint on the board. He even added solder. It worked! The light went off and the ABS works again.
However my buddy, who knows zip about electronics, read on the internet that you could restore the function of an ABS module on his truck by reflowing the solder joints. A new module was like $700 so he figured he had nothing to lose. He did not consult with me. He just opened up the module and reflowed every joint on the board. He even added solder. It worked! The light went off and the ABS works again.
electronics devices have many strange case
like you said, i have been feel it for 3 times
first, cheap old china TV CRT tube, the case is horizontal area
i have been checking and measuring them, everything is good but when power ON trouble comes so i think re-soldering IC pin will solving it and it done, this cheap old china TV CRT TUBE rises from its "death"
two, computer power supply, the case is green cable command pin
push power button but no power, so i open PSU then measuring all of them but they are just fine enough then looking back at mother board power pin, seems so good but i feel something weird about them so i think re-soldering is great and its done after they are shining back again
third, my relatives simbadda CST-7200 active speaker, left channel no sound
open it up but seems better after checking so re-tracking PCB trace and still no suspect then something is strange, left channel input seems have bad solder, so i give it hot re-soldering and they became stereo after it
i don't know why for them but that's so strange
Dry joint, it only takes one to cause a circuit failure... The skill is determining where the fault is a sorting it. This way you know where and how the gear failed. The first area to look in the gear you have mentioned is components that go through extreme heat cycles (power resistors) etc. these are the likely candidates for thermal stress causing a dry joint. There is no magic in this and it will save solder, avoid adding problems and you get to know what went wrong.
Re-making a bad joint is a valid repair technique, once the bad joint has been found via fault-tracing. Experienced repair technicians use this technique.
Re-flowing a good joint is a useful (but unreliable) fault injection technique, and may sometimes by accident fix a fault. Experienced bodgers use this technique.
Re-flowing a good joint is a useful (but unreliable) fault injection technique, and may sometimes by accident fix a fault. Experienced bodgers use this technique.
Use plenty of flux, there is normally enough solder on the board.
Do not 'overcook' the board and use a good quality iron with the correct temperature bit.
Speed is of the essence and look for any heavy component as in the audio industry, transformers, chokes and heavy capacitors, develop dry joints. Normally with good trained eyes, these can be easily spotted. Literally!
Do not 'overcook' the board and use a good quality iron with the correct temperature bit.
Speed is of the essence and look for any heavy component as in the audio industry, transformers, chokes and heavy capacitors, develop dry joints. Normally with good trained eyes, these can be easily spotted. Literally!
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