Cablemodem Motorola SB5100

[trodas]

It is already long time, when I upgraded my Motorola SB4200 modem to SB5100.



So when sometimes happen that after my ISP cable line went down and the modem crash (one just cannot enter the modem menu, available at http://192.168.100.1 ) and I can't rest it over the net - well - I started suspect that the caps might not be as good, as they can.
And when recently I noticed too much packet loss, that even it can by my ISP fault (as it usually is, just check there for graphic display how my ISP sometimes "rule": http://trodas.wz.cz/index.php?act=ST&f=8&t=151&s= ) I still decided to replace the caps in my cablemodem.

Motorola SB 5100
------------------------
1x 470uF 25V d10 4PZ -> 13.85V, 209mV ripple -> 470uF 16V GC d8
1x 100uF 25V d8 4QK -> 13.96V, 200mV ripple -> 220uF 25V GK d6.3
3x 330uF 10V d8 4LY -> 5V all, 0.7 - 0.9mV ripple all -> 470uF 6.3V GD d6.3
1x 470uF ???V d8 (r4, 470J, UD) -> 2.516V, 0.6mV ripple -> 1000uF 6.3V GC d8
1x 150UF 10V d6.3 4JZ -> 3.346V, 0.6mV ripple -> 330uF 6.3V FM d6
1x 47uF 16V d6.3 49K -> 2.519V, 0.6mV ripple -> 150uF 6.3V FM d5
2X 22uF ???v d4 (22, r6.3) -> 5.16V, 1mV ripple + 1.202V, 0.6mV ripple -> 68uF 6.3V FC d4

The catch? Well, all these Chemi-con caps are SMD ones, while the replacements are radial.




Luckily, there is not too many of them:




So, I just bend their legs to the sides, cut them to match their SMD soldering place size and solder them like that:









It is maybe not best-looking solution, but it works and the net seems now faster and less packets seems to be lost - but that can be just a coincidence, or I imagine it

Regardless, at least I now know that fault can't be in my modem

[PedroDaGr8]

Re: Cablemodem Motorola SB5100

LMAO THAT is impressive to me. Beautiful soldering. I wish I had that ability. I am too much of a soldering NOOB. Just realized recently, plumbing flux does not work well as soldering flux. LMAO

[Gianni]

Re: Cablemodem Motorola SB5100

Very nice job

Gianni

[Newbie2]

Re: Cablemodem Motorola SB5100

I have that same Motorola cable modem. I don't have any problems with it at all.

Replacing SMT caps like those I wouldn't think would be hard. Just remove the old SMT electrolytic caps, bend the leads of the new radial electrolytic caps to match the pad on the PCB, put the new cap onto the PCB, and apply solder. It's that easy if you have the right equipment. It's probably even easier than through-hole caps because there is less effort to remove them.

[Wizard]

Re: Cablemodem Motorola SB5100

I simply twist old SMD electro's off by gently gripping with needle nose pilers, press down and twisting back and forth slightly till legs breaks off.

Especially makes things go faster and less damage, clean up a snap.

That soldering quality you did is what I do all the time. And using these method using regular caps is far vastly reliable and lasts longer than those horrible SMD caps. I don't know why they want SMD electrolytic caps, I don't know why but for space reasons but..!? The ESR is frighteningly high even new.

The photos are so sharp, what camera is used for these photos?

Cheers, Wizard

[Gianni]

Re: Cablemodem Motorola SB5100

I don't know why they want SMD electrolytic caps

I guess their are better than thru hole cap to be mounted by automatic machine for manufacturers.

The photos are so sharp, what camera is used for these photos?

I have a Canon Powershot A620 but I'm not able to take so clear close up pics as trodas does, but I suppose the problem is not the camera

Gianni