Dell laptop power adaptor

[wallis]

Hello All,

Im trying to repair a dell laptop that keeps coming up with a warning that the power adaptor cannot be identified so the unit will run in a low power state.
I have found out that the id signal is sent via a Dallas 2501. I managed to salvage 1 from an old adaptor and wanted to fit it internally to the laptop to prevent any more issues. Only problem is the laptop still displays the same fault.

Can I test the dallas 2501 with a scope if so how, many thanks in advance.

Kind regards
Wallis
 

[KhronX]

What model laptop is that?

[wraper]

I have found out that the id signal is sent via a Dallas 2501. I managed to salvage 1 from an old adaptor and wanted to fit it internally to the laptop to prevent any more issues. Only problem is the laptop still displays the same fault.

Do you realize it's an EPROM? It needs to contain proper data in it, not to say that laptop may be faulty as well.

[Shock]

Put the pointy end of the probe on the data pin.

Did you confirm the fault lays in the adapter?  Does it charge at all?
i.e. tried another working adapter or checked for broken or intermittent contacts
Did you pull a 2501 off an identical adapter?
What makes you think the 2501 has the same ID?

The ID the 2501 sends could be anything from the wattage to model specific identification.

[wallis]

Hello its an Inspiron 8600 I had lying around, adaptor is PA-10 Family

[wallis]

Thats what Im asking , if there is a way to check the data with a scope?

[wallis]

yes yes the pointy thing indeed
I removed the 1205 from a PA-12 that is  compatible with the PA-10 
I wanted to know if there was a way to check  the component to see  if it was faulty as it does not cure the issue

[coromonadalix]

since this is an one wire eeprom   if you have or can find an programmer / reader to check it ....

few links
https://hackaday.com/2014/03/03/hacking-dell-laptop-charger-identification/
http://www.laptop-junction.com/toast/content/inside-dell-ac-power-adapter-mystery-revealed
http://www.laptop-junction.com/toast/content/dell-ac-power-adapter-id-chip-died

http://320volt.com/en/dell-pa-12-laptop-smps-19v-3-34a-adaptor-semasi/
http://www.instructables.com/id/Modify-a-Dell-Laptop-Power-Supply-PA-10/

[coromonadalix]

oh i forgot,  sometime the problem is the center pin who get loose and break in the connector, or the soldering break,  i had these problems and resorted to china adapters for 1/3 of the price,  up to this day they still get going

When i dismantled the connector i found out why it failed ...

[Shock]

yes yes the pointy thing indeed
I removed the 1205 from a PA-12 that is  compatible with the PA-10 
I wanted to know if there was a way to check  the component to see  if it was faulty as it does not cure the issue

Check yes by probing the data pin. Check if faulty means you will have to debug (translate) the communication and ID info that is sent from the 1205, which is not a quick or especially easy for you. To ensure any replacement is 100% the same you would have to program it.

Always prove the fault exists before embarking on large wastes of time. It's easy to google and jump right in and think it must be the 1205, reread my earlier post, you have to rule out other assumptions first. If you have already tested continuity and intermittent connections in the signal wire and that the adapter is functioning fine otherwise, the next logical choice is try another identical adapter which should work perfect. Then you know with fairly high confidence something is not right with yours.

You might want to check this out because it seems there is other funny business going on with underrated adapters, you need to confirm all this type of stuff first.
https://www.dell.com/community/Laptops-General/A-PROBABLE-solution-to-ADAPTER-problems-Inspiron-8600-and-maybe/td-p/1403188