More SMD nuisances

[J M Fahey]

Just on the edge of starting it, I am also seeing more and more components, mainly some kind of IC, is available only in SMD.

What do I think I´ll do?: I´ll bow to the almighty SMD-only IC (let´s be realistic) **BUT** it and only it.

I guess (at least for what´s left of my life, and later ... who cares?) resistors and capacitors, 90% of components in a PCB will continue being made in through hole versions , as well as larger electrolytics, power transistors and such, so I´ll continue designing and making basically through hole PCBs , which from now on will *incorporate* (VERY different from "being based on") a couple SMD chips ... on the solder side of course.

For example, my cheap "reverb" based on PT2399 is still being based on through hole chips, since I have quite a few left ... but when I have to reorder, SMD ones are way easier to find, from reputable suppliers (through hole ones are lately available only through EBay or from Hong Kong or Shenzhen/Guangdong dealers) so next PCB batch will be the exact same old standard ... just with some added DIP SMD pads on the copper side.

Hand mounting a couple SMD chips in an otherwise through hole PCB? ... I guess I´ll survive

A full SMD board? .... forget it.

[The Dude]

I've run into that problem myself (chip only available in SMD form). I just used something like this.

https://www.ebay.com/itm/5pcs-SO16-T...gAAOSww~xZzv57

That was for a single repair, though. I totally understand it may not be practical for manufacturing purposes.

[drewl]

Plenty of parts out there you can harvest from old junk.

That's what I've been doing.
Pulling chips and transistors from old stereos and obsolete equipment.

[nevetslab]

I've run into that problem myself (chip only available in SMD form). I just used something like this.

https://www.ebay.com/itm/5pcs-SO16-T...gAAOSww~xZzv57

That was for a single repair, though. I totally understand it may not be practical for manufacturing purposes.

^^^^^^^^ That! I too have a small collection of those to use with the SMD-ONLY IC's that are worth using. Clumsy, yes, but gets the job done. I cursed the day when my soft-handled stainless steel Erem tweezers escaped from their home in my drawer. Ever try to demag steel tweezers that are size-jaw-suitable to mange SMD parts, only to have the residual magnatism keep causing the little buggers to jump up and attach themselves? While I've since purchased a couple replaceable plastic and ceramic jaw style tweezers, they just DON'T have the ease that those Erem tweezers had. Just too expensive to go buy a new pair.

[olddawg]

^^^^^^^^ That! I too have a small collection of those to use with the SMD-ONLY IC's that are worth using. Clumsy, yes, but gets the job done. I cursed the day when my soft-handled stainless steel Erem tweezers escaped from their home in my drawer. Ever try to demag steel tweezers that are size-jaw-suitable to mange SMD parts, only to have the residual magnatism keep causing the little buggers to jump up and attach themselves? While I've since purchased a couple replaceable plastic and ceramic jaw style tweezers, they just DON'T have the ease that those Erem tweezers had. Just too expensive to go buy a new pair.

I used to do that.. in my last move I almost threw out a big old 1970s SAE graphic equalizer.. until I opened it up and saw all of the American 4558 opamps and transistors. Of course it’s in a box in storage until I die probably! Lol!

[Leo_Gnardo]

I used to do that.. in my last move I almost threw out a big old 1970s SAE graphic equalizer.. until I opened it up and saw all of the American 4558 opamps and transistors. Of course it’s in a box in storage until I die probably! Lol!

Is that the big black half octave 2700 or MkXXVII stereo EQ? Pleeeeze don't rip it apart for op amps. Those are dam' fine EQ's. Granted these days who would carry around a cubic foot of EQ when it can all be done with a couple touches on digital buttons. OTOH I have one and it served me well in PA days. Also I recommended a friend grab one for his home rehearsal studio when it was available for a very reasonable $125. So he did and very pleased with it.

[nickb]

Hmm..I must be a in a party of one.

I find it must easier to replace a SMD part provided it's not a very fine pitch part than to pull a thru-hole one. Less chance of damaging the PCB too. My technique is to use two fine pitch irons and a microscope (essential). I can still do the fine pitch ones but it does take more effort. Lead-less parts are done with with my SMD hot air tool, it helps to have some preheat on the rear. I draw the line at BGAs and big heat pad types as I can't be confident of the quality if I can't see it.

[Tony Bones]

SMD does get easier if you do enough of it. The technique is completely different. Sharp tweezers, sharp (and clean!) soldering tip. Microscope is required for small pitch stuff, still can be helpful with the bigger parts. I've gotten spoiled and use a microscope for just about everything now. Even tube amps sometimes! Being able see what you're doing makes the difference sometimes.

I can understand not liking SMD, but if you're designing something that needs to be really small, then there's no other way. And these days, battery powered hand-held stuff is all really small.

[J M Fahey]

I can understand not liking SMD, but if you're designing something that needs to be really small, then there's no other way. And these days, battery powered hand-held stuff is all really small.

Well, let´s not mix oranges and apples

If you design something which will later be made in China in commercial amounts, by all means go with what OEM manufacturer suggests, which will be robot made SMD stuff, simply because it´s faster and cheaper.

If you make smartphone sized stuff, same thing.

Now any M.I. amplifier is cavernously large compared to those, so if wanting to use through hole components to make self in house assembly possible, that is not a deal breaker by any means.

And as of servicing, obviously stuff bought commercially, IF you can charge for your time it pays to repair SMD stuff, so equip accordingly and practice necessary skills ... but if product is dirt cheap you have a very low roof over your head, often so low that you simply can´t fit under it.

From comments in other Service Tech pages, in principle "nobody repairs pedals", be it SMD or through hole, simply because average price is around $60, and "nobody recones speakers" , again for the same reason.

It´s only worth reconing PRO ones such as JBL, or maybe some revered 60´s Alnico Jensen , and old revered pedals such as the "Satisfaction" Maestro fuzz, which was being discussed in another thread ... but those are the exceptions, not the rule.

[drewl]

I repair pedals every week.
Usually broken switches or pots/Jack's or dead IC's or wrong power applied failures.

Easy cheap fixes, or the occasional rare pedal that you can charge more for.

[J M Fahey]

More power to you

Just curious, how much do you charge for those fixes?

[drewl]

Depends, usually $35 - $50 depending on parts.

Rare or valuable stuff more.

[J M Fahey]

Ok, if customers pay that, fine.
In general they complain "I can get another for that price"

[Leo_Gnardo]

Local music store - as of a couple years ago - charges $50 up front "look at" fee for effects pedals. Probably more now... Me, I'll have a go at the ones I reckon I might be able to fix. No fix, no charge so I do try to screen out the obvious losers. Sometimes it's just an in/out jack, a battery clip, a shorted DC protection diode maybe its accompanying resistor is also toast. OTOH I have some real tough nuts I need a real expert to sort out - mid 70's Tycho Brahe pedals that are probably $$$$ collector items if they can be made to work. IC's in them have their ID numbers ground off, grrr......

[drewl]

Guys on pedal building sites have figured out and traced about any pedal you can think of.

And yeah, you can get a replacement for maybe $5 more than a repair cost, but the repaired unit is re-furbished and won't die like a replacement might.

Like this week I had to replace the missing actuator for a Vox Time Machine delay.

I had four be from when I replaced the PC board mounted switches on a Line 6 DL4 with regular footswitchable years ago.

$0 in parts, ten minutes to fix, a quick $35 for a pedal that cost $130.