recap question re hard to reach capacitor

[jazzzman]

I saw on a vintage radio repair site a method of replacing a capacitor on a pcb with an inaccessable underside. The method entailed coiling each leg of the new capacitor around a stiff wire or needle, cutting the old capacitor from its legs close to the capacitor's body, cleaning the legs, slipping each coiled leg (after removing the wire or needle) of the new capacitor over a leg of the old capacitor and soldering the coils to the old leg.

I have a circa 1978 Pioneer PL-610 turntable that works flawlessly. I am afraid that it is only a matter of time before the old electrolytics give me a problem, so I am thinking of recapping it. My concern is that the motor board has some capacitors that will be quite challenging to replace if I have to solder from the underside of the board. (The motor flange essentially blocks part of the bottom of the pcb, requiring the use of a long tip and steady hand to reach the ends of certain capacitors.)

I was thinking the job might not be something I could handle and then I stumbled upon the above method. Does anyone see any problem with coiling the legs of a capacitor as described above?

Thanks for any help you can give me.
Jazzzman

 

[east electronics]

bad approach ...

most of these solderings are done in a soldering bath ...were the amount of solder is very low ...means that if you warm up the "upper side" someway somehow you will loose the soldering down under

soldering done in a bath ensures an amount of solder that most of times is just about enough ...add to this that solder is more than 30 years old and you are done .

yes it might be hard to do but just do it properly 610 was a nice player ...looked nice also ...so do it !!!

 

[Conrad Hoffman]

Good idea! This method has actually been recommended by several major test equipment manufacturers to avoid mucking up multi-layer boards and for changing parts that are mechanically difficult. There's no shame at all in doing it this way. I would bother with any fancy coils, just a single turn and bend to grasp the old lead. Put a bit of hot glue under the new part if you're worried about mechanical stability- usually a good idea on any big cap. Because the traces act as a heat sink you shouldn't bother the inaccessible joint unless you really overdo the heat. Just use low to normal settings and be quick about it.

 

[indianajo]

I did something like this to the 6 preamps on my organ. I cut the old cap leads long, bent them over, bent the leads on the new caps, hooked them over & soldered them. At audio frequencies, extra length is not a problem. The organ sounds great, 1 cold joint was microphonic but I found it by wiggling. That one had been a ***** to get the cap to stick, the leg was loose in the PCB but with the hooks it didn't come out. Hammond bent their legs on the pcb pad. No problems in the 2 years since then.
I've lifted some pads off the PCB's on my dynakit equipment, also on this peavey stuff. This is better for amateur tools and technique. I'm using a WP25 iron with a screwdriver tip, and old wire for solder sucker. Very low budget operation here.

 

[jazzzman]

Thanks for the responses. I might try putting an alligator clip at the end of the old leg while soldering to dissipate additional heat and hopefully prevent the old solder from melting.