Re: strange behavior of external esatausb ports on a Dell laptop
On 08/26/15 11:17, jd1008 wrote:
On 08/25/2015 10:36 PM, g wrote:
>
> On 08/25/15 21:15, jd1008 wrote:
>> On a Dell E6510 laptop, there are 4 ports: 3 USB, and 1 eSata.
>> The ports on the left side of the laptop are USB and eSata.
>> Both of these ports start losing voltage after some time of
>> operation, say ....1 hours to 5 hours.
> <>
> .
> did you web search or dell site?
>
> does voltage decrease to 0.00 v?
>
> boot to bios or a live cd/dvd. monitor voltage. if still happens,
> i would guess hardware.
>
>
There does not seem to be any google hits on what I see taking place.
Dell support is not help. They just want you to buy a new mobo.
Voltage does not go to zero - because the tiny usb fan drops it's
rpms, but does not stop. So, perhaps it is not the voltage that is dropping,
but the amperage???
.
ok, lets look at this another way...
you say you are on ac, so that _might_ eliminate battery's voltage dropping,
unless wall wart is failing, or failure in voltage regulatory circuits.
ac input from wart is rectified in laptop and then feed to the various
regulator circuits. it is possible that there may be a vlsi chip that
does all the voltage regulating by feeding control voltages to output
power transistors. voltage regulation can be done in many ways and only
the oem knows for sure, unless supplied in specs or schematic.
does laptop have indicator light to show battery/charge state, ac power
state?
do you have battery state icon on a panel that you can watch? if icon shows
a state of 100% that later drops, that will give a clue of problem being
in voltage regulator circuit or in usb port chip/s.
you really need a VOM, Volt/Ohm Meter. a fan is pp for accurate measuring
of voltage fluctuation.
with vom, you can monitor voltage output of wart to see if it drops.
for laptop, when voltage drops, as measured at usb port, you would need to
have a way to measure battery while still connected. when you state that
you have a vom, i will go into further.
because you have failure on one side and not other, tends to indicate that
each side is on a separate regulator circuit. left side regulator could be
heating up and failing.
which brings to mind, is this same laptop you inherited that had over heated
and you replace cpu, then found it to be gpu?
voltage/amperage regulator chips are of type;
cv/va = constant voltage, variable amps
ca/vv = constant amps, variable voltage
cv/ca = constant voltage, constant amps.
the 'constant' is usually fixed or settable, 'variable' will have a max
rate.
i will presume that the regulator in laptop is cv/va, so unless chip has
heat failure, amperage is not a factor.
--
peace out.
If Bill Gates got a dime for every time Windows crashes...
...oh, wait. He does. THAT explains it!
-+-
in a world with out fences, who needs gates.
CentOS GNU/Linux 6.6
tc,hago.
g
.