How to treat my first recap?

[Rangefinder]

Well gang, here goes my first thread.
I have a pair of Klipsch ProMedia Ultra 2.0 speaker hooked to my laptop. Only bout 4 yo. I have moved several times these past two years. The puter is on a deep table with the speaker less than three feet apart and w/ the left sp near my seat.
Just this last week I came to realize that the right sp wasn't working. I checked all connections, (aber es war kaputt). I opened the right speaker and exposed the T amp there. One of the 470mfd caps had . The second 470 cap was deformed and not long for this world. The amp is on two boards ,one on top the other. A chore to separate. Only the two 470s were bad but since it was a chore to get in there and separate the boards and since the caps in this amp are Chinese it occurred to me that it might be best to change all electrolytics (10 caps all total).Thoughts ? Digikey has the panasonic caps needed.
The caps that blew for Panasonic is a higher voltage but I see no prob since the size is ok. If I do replace all the caps I thought to bump the voltage on the others as well since one value is only available at a higher voltage. The other concern in a question of what solder was used in the assembly. I use 63/37 out of habit. The boards are separated and the bad caps removed. I have been away from the bench for a number of years and the hands have turned to crap. I sure miss the Pace solder sucker used on my last job. Any and all comments gratefully accepted

[kaboom]

Re: How to treat my first recap?

Use the eutectic.

If this 'chinese' thing has that lousy PCB material, you better only tear it apart once- don't want to lift the traces.

You may find that it'll alloy/look bad with any remaining RoHS crap on the board.

On appliance boards, when I resolder relay pins, I'll add some 60/40 for heat transfer. Then wick or suck it off, sometimes more than once if the relay is sealed to the board with poly-u.

Otherwise, I'll remove the relay and tin/remove solder from the pads to clean the junk off. Once they look nice, back the relay goes with 60/40 or 63/37.

-Paul

[ratdude747]

Re: How to treat my first recap?

On appliance boards, when I resolder relay pins, I'll add some 60/40 for heat transfer. Then wick or suck it off, sometimes more than once if the relay is sealed to the board with poly-u.

Actually (I've said this before), you ALWAYS add fresh solder before you desolder... the extra heat transfer and flux makes desoldering work much more efficintly.

cheap chines board do have a habit of lifting traces, so have some thin jumper wore in case you have to bypass a split or lifted trace. If possible, avoid using braid on this project as the high heat used in desoldering braid will lift traces a lot (heat is what causes lifting)

[kaboom]

Re: How to treat my first recap?

I should've been clearer.

I've worked on things where there was plenty of solder to begin with and it wasn't this rohs junk. In these cases, there was good heat transfer as it was for desoldering; wick, sucker, or "lead-walking." Of course, everything was properly soldered afterwards. And having good flux makes such a difference, both for making the joint as well as in the wick.

Those cheap boards are such a pain. In the case of those cheep nasty Labtecs I rebuilt, I used these tiny hemostats to grasp component leads. Heat and melt the solder, and the slightest pull removes one end of a resistor. Heat the other lead and it falls right out. To remove the remaining solder on that board, I used good wick and a fat little copper chisel tip in a Weller SP23 iron. For larger areas, an American Beauty with the heater inside the tip.

When I recapped my Sansui 881, I also used that weller. I'd 'lead-walk' the cap out, then clean the hole with the wick. Holes were cleaned in less than a second, usually around half a second once the wick was hot. No lifted traces.

-Paul

[Rangefinder]

Re: How to treat my first recap?


The board looks pretty good , its a glass board. My question is to weather I should go ahead and change the other 8 caps and save me the trouble of coming back later
for a redo.
Had to relearn how to do the one hand solder sucker cock. My hand still hurts (old hands). I've been on the sideline too long and I'm having to retrain the hands.
Sure miss that Pace solder sucker, Just don't have the price for one.
It was handy to bring stuff in to work for a rework. That all went off shore too.
Going to have to get some wick that has flux in it. What I have here doesn't.
Don't remember why but I know I had a reason.
Thanks for the comments keep coming back w/ more..

[kaboom]

Re: How to treat my first recap?

Definitely replace them all.

The LCD monitor I'm using now (Compaq FP7317) was trashed because of a bunch of nasty Hermeis. At first, I just replaced the ones after the rectifiers, before getting the rest. I was using another monitor at the time, so I just tested/verified it quickly and put it aside. Once I got the others and replaced them all, it was nice to know that the caps would be 'outta sight, outta mind.'

-Paul

[Rangefinder]

How to treat my first recap?

Thanks Paul. I just needed some reaffirmation of my thinking. Its just having been out of harness for so long and the hands are almost gone. Forgive the whine.

[Agent24]

Re: How to treat my first recap?

I site I found which has details of some of the systems
(http://www.thompdale.com/bash_amplif...1_bash_amp.htm)

Shows what looks like all G-Luxon and CapXon, both brands are fairly useless.