Thinking of Recapping a D-Link DSL-G604T router

[KevinR]

I make good use of old(er) routers with the 3rd party RouterTech firmware. One of these is refusing to recognise 100base-t ethernet but is happy at 10base-t speeds. I've seen on the web a similar model of d-link and some other brands where this problem has been fixed by replacing some of the caps.

I found one thread here on BadCaps that mentioned the G604T but no feedback about if the recap worked.

Examination of the router reveals the majority of the Electrolytics are GSC and the rest are TBOR (if I read the logo correctly).

There are:
GSC 1000uF 35V x2 - main PSU caps + space for 2 more.
TBOR 225uF 35V x1
TBOR 220uF 16V x5
GSC 100uF 16V x8
GSC 47uF 25V x4

None show any obvious damage.

Supply is 12V AC 1.2A (ie. unregulated). So I think those capacitor voltages are all pretty nominal.

Some Questions:
Has anyone recaped a G604T?
Is it worth giving it a go given the brands involved?
Is it better to work in sections, testing as I go?
Or just do all of them?

I'm assuming an old Oryx-50 iron should be able to pump out enough heat with the aid of some desoldering braid or a cheap sucker?

Aside:
One thing I have learn while researching this is that many (most?) smaller capacitors like those above are only rated for 1000 hours at full load. And that was Panasonic FC. In a router left on 24/7 that's only 41 days. Even if we assume they'll last rather longer at more moderate voltages, temperatures, & fluctuations you need a factor of 9 to last a year. These routers were made from about Nov-2003 so some of them need need x53 for 6 years. So to some extent failure can't be surprising, even if its breakdown rather than leakage or blowing.

[370forlife]

Re: Thinking of Recapping a D-Link DSL-G604T router

Can't hurt (as long as it's not a life-or-death piece of equipment). Caps are cheap (depending on where you live,) as long as you don't botch it soldering try it and report back

As for the life-time:

Their rated life is at the highest rated temperature, voltage, ripple current, and other factors. Rubycon says that for every 10C drop in temp the life span doubles, and thats not counting lowering other factors like ripple, voltage, etc...

The lowest rating I have seen on a good cap manufacturer is 2000hrs, even so they can usually last longer than their rating.

[KevinR]

Re: Thinking of Recapping a D-Link DSL-G604T router

I will probably give it a go, as #1 is now the spare and its ethernet is now slower than the line sync.

I may have to change router & especially chipset anyway to get the best out of my ADSL2+ LLU line, so its not much of a risk. The replacement G604T (#2) is doing OK (about 12Mpbs sync), but either the line or it is doing less well than theory suggests (about 12-20Mpbs depending where you look).

I'll need to get some desolder braid at less than Maplin's mad price, etc!

The figure on the capacitor life came off Farnell's website for the Panasonic FC range. The small ones were 1000 hours. Rising for the bigger caps. It varies by voltage, capacitance and dimensions. Here's the Spec sheet for the Panasonic FC at Farnell At 25V (and below) the 100uF are only 1000 hours (at max loading ofcourse), the 1000uF are 3000 hours at 16V (and above). At certain values the capacitor proportions affect the lifespan.

So in these examples the main capacitors at 1000uF may well be ok (with a good brand or cool router) BUT the little 100uF ones are more at risk.

Even given the rule-of-thumb you quote, to guarantee 6 years out of a 100uF (even an FC) versus 1000 hours continuous operation at 105C we need that factor of 53. Now 2^6 = 64 and is more than 53. So we have to keep the circuit below 45C (105-(6*10)) to get over 3.6 years (41*2^5 days) life.

Comparing that with a lesser Panasonic with only 85C max temps, we'd lose 20C from the rule-of-thumb and need 25C max temperature to get into the 6 year lifespan. And routers get a lot warmer than that! Assuming the use of cheaper capacitors.... oh look mine's got GSC.... well it does feel iffy.

[japlytic]

Re: Thinking of Recapping a D-Link DSL-G604T router

The GSC units are straight after the AC bridge rectifier, so they should be no problems.

Have you tried updating the firmware in the router? Version notes can be found at:
ftp://files.dlink.com.au/products/DS...ease_Notes.txt (Revision A units)
ftp://files.dlink.com.au/products/DS...ease_Notes.txt (Revision B units)
ftp://files.dlink.com.au/products/DS...ease_Notes.txt (Revision C units)

Don't forget to perform a factory reset before and after firmware upgrades.

If you still have problems, try replacing the electrolytics.

[stj]

Re: Thinking of Recapping a D-Link DSL-G604T router

isnt the Oryx a Butane gas iron?

[Agent24]

Re: Thinking of Recapping a D-Link DSL-G604T router

I was recently given a DSL-G604T which apparently would keep losing settings etc. I figured bad capacitors might be an issue.

It's full of GSC and TWBOR (that's the correct name) same as yours, though nothing is visually bad. I suspect they haven't got to that stage yet or have dried out instead.

I'm thinking of recapping in the future and then just seeing what happens.

[japlytic]

Re: Thinking of Recapping a D-Link DSL-G604T router

The 8 most important capacitors to replace are:
C45 (input filter)
C5, C184 (+3.3V)
C204, C61 (+3.3V)
C1 (+3.3V)
C79, C81 (+12V regulated)

C132, C151, C152 and C157 are the input filter (should be OK as-is)

[japlytic]

Re: Thinking of Recapping a D-Link DSL-G604T router

C81 should be C91. My mistake