Dell Inspiron 1545 laptop- wired ethernet nonfunctional

[wAYNE]

I have been using a Dell Inspiron 1545 for years at home. For Internet,
I've always used the wired connection via cat5 cable to the router
without issue, that is until recently. This morning, I seemed to not be
able to make the connection. Since I am using a dual boot system,
either Ubuntu or Win10 at startup, I decided to boot into Win 10 and
experienced the same symptoms.

On Ubuntu 22.04, there is a question mark in place of the normal
connection icon. On Win, no network connection.

I recently changed out the motherboard in the 1545 and for several days,
the wired connection was working fine without issue.

To test if I could connect via WiFi, I enabled that in the laptop and
the router. I normally use nothing but wired connections at home, so
had to create and enable the connections for both items. The laptop
connects to the Internet fine by Wifi with no issues.

What could be causing the unsuccessful wired connection?

Thanks in advance.

[Peter W.]

On Tuesday, October 11, 2022 at 1:10:30 PM UTC-4, wAYNE wrote:
> I have been using a Dell Inspiron 1545 for **years** at home. For Internet,

> I've always used the wired connection via cat5 cable to the router

My S.W.A.G. is that the connector is worn out. Keeping in mind that the laptop makers expect that most users keep their devices for only a very few years, and never move them, it is no surprise that a connector would have worn out under the conditions you describe.

Peter Wieck
Melrose Park, PA

[wAYNE]

Hmmm. Well, the motherboard was swapped out for a refurbished one. I
suppose it's possible that the connector may be bad, although I doubt
whoever used it before probably used it wired like I have for years. Is
there a chance that it might be some sort of corrosion or oxidation from
NON use? Anything I could try spraying into the connector or applied to
it for a test?

[Peter W.]

> Is there a chance that it might be some sort of corrosion or oxidation from
> NON use? Anything I could try spraying into the connector or applied to
> it for a test?

Generally, look at the end of the connector. If the little wires inside are not even, clean and show even small signs of corrosion, then the connector(s) are likely bad. Have you changed the cable? Note that the bad connection could be in the cable or in the modem/router. And, check the board. That jack may have been strained at some point and broken a solder connection - especially if there are cats/dogs/small children involved. I would very much hesitate to spray anything at all into a jack - as anti-corrosives such as DeOxit continue to react until all the materials have been 'used up' - which could do considerable and fatal damage to a mother-board. If you are _EXCEEDINGLY_ careful, you might try 91% (or more) alcohol on a small brush or small cotton swab - but the potential for collateral damage is high without that extreme care.

If the jack in the computer is on a smaller daughter-board, you might try removing it, and then plugging it back in.

This reads as a mechanical fault as the computer does behave 'as normal' on WiFi. Unless, of course, something got spiked recently. Any surges from your power?

[wAYNE]

I tried using a modified pencil eraser over the connections and, no,
they didn't look out of place or corroded as far as I could tell. Yes,
I tried switching out the cables to known good ones to no avail.

Since the charger board, which contains the USB, charger and ethernet
ports can be removed and replaced, I have another one here I could try
or simply order a known good one. I've been wanting to try one anyway
since I have another laptop here that won't respond as I have been
suspecting the charger board.

Thanks for the tips, however.

[whit3rd]

On Tuesday, October 11, 2022 at 12:02:10 PM UTC-7, wAYNE wrote:
> On 10/11/22 2:55 PM, Peter W. wrote:

> > Generally, look at the end of the connector. If the little wires inside are not even, clean and show even small signs of corrosion, then the connector(s) are likely bad.

> I tried using a modified pencil eraser over the connections and, no,
> they didn't look out of place or corroded as far as I could tell. Yes,
> I tried switching out the cables to known good ones to no avail.

A typical problem in the old days, was a bent connector wire, caused by plugging in
a modem cable (6position) which dented wires 1 and 8 of the 8 position RJ45.

There are USB plug-in Ethernet adaptors, not very expensive, if you need the function...

[wAYNE]

Interesting, never thought of that. I see some with Linux/ Win
compatibility. I wonder though, would there be a degradation of speed
with USB2 as that's the fastest this old laptop has?

[whit3rd]

Both the USB and the Ethernet (10baseT, 100baseT, or 1000baseT) are bottlenecks,
but the interfaces are compatible and USB2 is faster than some, slower than other, Ethernet
networks. My TiVO is happy with its USB/Ethernet adaptor, and that might not even
be USB2 (it is a Linux box).