Recapping. First, do no harm

Ray Gianelli

Super Member
I recently bought an amp needing repair. It is a fairly recent piece, probably manufactured in the mid 90's. Apparently someone decided to recap it. To their credit, they made good choices in capacitors, mostly Nichicon PW in power supply and Gold Tunes in the audio.

However, as I disassembled the unit to assess what needed repair I saw damage caused by poor workmanship during the recap. Here's a pic:
Recap.jpg
The board has caps on both sides. You can see here where the pads were ripped off during the removal of the old (and considering the age, probably still good) filter caps. Pretty sure these caps on the bottom aren't filtering a damn thing.

I'm going to have to examine all the boards looking for other damage. It's a crying shame; this is a quality high dollar amplifier. I purposely haven't mentioned the make and model, as I bought it in BarterTown and I don't wish to insult or embarrass the previous owner.

So the purpose of this thread is to say if you don't have the skills or the proper tools don't damage something while trying to improve it. So take the Hippocratic Recap Oath: First, do no harm!
 
So the purpose of this thread is to say if you don't have the skills or the proper tools don't damage something while trying to improve it. So take the Hippocratic Recap Oath: First, do no harm!

I see this all of the time - equipment comes in after someone watched a YouTube Video and then they think they can fix their own equipment. A regular question we now ask is - have you tried to repair it yourself?

This is not only a problem that consumers cause, I also see it on equipment that has been recently worked on by other shops - a few weeks ago, we had an amplifier come that another shop worked on, they install many used parts - some date as long as 20 years ago as part of the repair (?) and these weren't any type of highly specialized parts that are impossible to find, just things like ceramic caps and electrolytic's. It's shameful what gets passed off now-a-days - Chris
 
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I see this all of the time - equipment comes in after someone watched a YouTube Video and then they think they can fix their own equipment. A regular question we now ask is - have you tried to repair it yourself?

This is not only a problem that consumers cause, I also see it on equipment that has been recently worked on by other shops - a few weeks ago, we had an amplifier come that another shop worked on, they install many used parts - some date as long as 20 years ago as part of the repair (?) and these weren't any type of highly specialized parts that are impossible to find, just things like ceramic caps and electrolytic's. It's shameful what gets passed off now-a-days - Chris
Chris, that's amazing.

Considering how cheap even good quality parts are these days that's just unconscionable.
 
A good desoldering iron makes all of this so much easier. I honestly don't know how I got on without it. Probably by ripping solder pads off boards.
Right?
I will say this: I invested in good quality soldering/desoldering tools before I started working on other people's gear.
 
Any other blatant 'cap happy' pics? We had a recent poster who even before he received the unit was planning a full recap. No testing thought posted.. I also had a pm asking how to service restore a realistic sta-2100 that was an all in one 'eager' wish list and how to do it! The list response would encompass a frigging manual! I just wrote/ replied politely post it on diy or SS forums.
 
Looks like there was a failed attempt at jumpering to a trace there as well.
There's a bit of work to do there for sure.
 
A good desoldering iron makes all of this so much easier. I honestly don't know how I got on without it. Probably by ripping solder pads off boards
True... but if you ever saw me with my wedge tip at 600 watts and solder wick, you would probably think me a caveman.. but I cut my teeth in aerospace burning through conforma-coat to do rework that had to be certified when I was done. It's not so much the tool but how you use the tool. I used wick for years before desolder stations were cheap enough to be common. I've got my pencil tips too but the only thermostat control is my sense of timing. Someday I will upgrade my weller but it gets the job done for me. And it's a rare day I lift a pad.. even on the late 70s ken woods with tissue paper copper traces. I wont use any of this for SMT work, thats a different beast all together.
 
I see this all of the time - equipment comes in after someone watched a YouTube Video and then they think they can fix their own equipment. A regular question we now ask is - have you tried to repair it yourself?

This is not only a problem that consumers cause, I also see it on equipment that has been recently worked on by other shops - a few weeks ago, we had an amplifier come that another shop worked on, they install many used parts - some date as long as 20 years ago as part of the repair (?) and these weren't any type of highly specialized parts that are impossible to find, just things like ceramic caps and electrolytic's. It's shameful what gets passed off now-a-days - Chris

Honestly, I don't even want to know anybody that would bother pulling and saving and re-using ceramic disc caps.
 
but if you ever saw me with my wedge tip at 600 watts and solder wick, you would probably think me a caveman.

Having a hot enough iron makes wick work. A better iron was something else I bought a while ago and have not regretted it for a minute. Also works to help not lift traces, in and out quick puts less heat into stuff so the pads don't lift. Trying to do this stuff with a 30w Radio Shack iron just does not work.

they install many used parts

Seems amazing anyone would even do that. I bag and tag parts when I pull them. Once the amp gets a checkup to make sure everything is as it ought to be, the bag of old crap goes in the trash. On the rare occasion it isn't for me, the bag of junk goes back to the owner. I have bodged used parts into things for quick and dirty testing but I would never dream of charging money for that.
 
I did some power supply repair work. I don't think I've seen a ceramic cap that was bad, unless it was physically damaged. Electrolytic caps, dies, transistors, bridge rectifiers are another story.

Lifting circuit board traces does happen, but, yes, the right iron heat & tip affect things greatly. Then, there's the traces totally burned off the board, or, corrosion got through the board coating.
 
True... but if you ever saw me with my wedge tip at 600 watts and solder wick, you would probably think me a caveman.. but I cut my teeth in aerospace burning through conforma-coat to do rework that had to be certified when I was done. It's not so much the tool but how you use the tool. I used wick for years before desolder stations were cheap enough to be common. I've got my pencil tips too but the only thermostat control is my sense of timing. Someday I will upgrade my weller but it gets the job done for me. And it's a rare day I lift a pad.. even on the late 70s ken woods with tissue paper copper traces. I wont use any of this for SMT work, thats a different beast all together.
Ugh. I used to repair flow meters made by Fischer and Porter that were coated. I hated working on boards that had conformal coating. I tried solvents to break it down, wire brushing it away in the area I was working on. In the end it just seemed easiest to burn through it with the iron.

Mike, you're absolutely right when you say it's not so much the tool but how you use the tool. Many would wreak havoc with a 600 watt wedge tip iron, but your experience makes it work without damage. Especially when using wick, high heat is a winner. I'll go as far to say that you're better off with high heat for a shorted duration than lower heat at a higher one.
 
I did some power supply repair work. I don't think I've seen a ceramic cap that was bad, unless it was physically damaged. Electrolytic caps, dies, transistors, bridge rectifiers are another story.

Lifting circuit board traces does happen, but, yes, the right iron heat & tip affect things greatly. Then, there's the traces totally burned off the board, or, corrosion got through the board coating.
Hey, a new guy... welcome to Audiokarma! I think you'll find this is a wonderful site, with a collective knowledge that is, IMHO, second to none. Plus, the mods here are on top of things so the signal/noise ratio is extremely low.
 
I've repaired a few Ford ECMs with conformal coating. Theirs is basically clear silicone rubber, not too hard to carefully cut a little circle out to re-cap them. The capacitors leak juice and start rotting the PCBs. Have to catch it before it goes through a trace or you're SOL. I fixed a Ford PSOM (Programmable Speedometer Odometer Module) out of a 90s Bronco that died that way. Cap leaked goo, rotted the main power feed trace. Found it under magnification and I was able to bridge the damaged area with a piece of component lead. Maybe not the prettiest repair but it did work once I was done.
 
...This is not only a problem that consumers cause, I also see it on equipment that has been recently worked on by other shops - a few weeks ago, we had an amplifier come that another shop worked on, they install many used parts - some date as long as 20 years ago as part of the repair (?) and these weren't any type of highly specialized parts that are impossible to find, just things like ceramic caps and electrolytic's. It's shameful what gets passed off now-a-days - Chris

Unfortunately, I've seen this a number of times as well; this is a 'recapped" Marantz 1070.

1988 caps.jpg
 
What I've encountered, is damage done by well meaning people attempting to troubleshoot something they don't understand, by swapping parts. Then I get a broken item which has the original problem, plus a bunch of badly installed parts which may create new issues. Yay. I much prefer getting something which is original, but then don't we all.
 
What I've encountered, is damage done by well meaning people attempting to troubleshoot something they don't understand, by swapping parts. Then I get a broken item which has the original problem, plus a bunch of badly installed parts which may create new issues. Yay. I much prefer getting something which is original, but then don't we all.

My dad is a retired auto mechanic. One of the things he burned into my brain is - when you look under the hood (or bonnet, for Queens' English speakers) and there's wires there which don't belong - walk away. Very true in the audio world, as well as the automotive !
 
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