Re: HP HSTNN-HA09 laptop power brick - power led turns off

Hi all,

I made a mistake in my last post:
R56 is [B]750[/B] Ohms (SMD marking not easy to read).

Best regards.Re: HP HSTNN-HA09 laptop power brick - power led turns off

Hi all,

I made a mistake in my last post:
R56 is [B]750[/B] Ohms (SMD marking not easy to read).

Best regards.Re: HP HSTNN-HA09 laptop power brick - power led turns off

Hi all,

I made a mistake in my last post:
R56 is [B]750[/B] Ohms

Re: New Members - please post your introductions here

Hi,
I'm Tppc I studied electronics but work on Industrial software applications developpment.

I live in FRANCE.

Re: HP HSTNN-HA09 laptop power brick - power led turns off

Hi all,

Just in case you ar still interested in repairing this AC adaptor,
I have good news for you. I just repaired mine this morning.

It had exactly the same problem as described previously in this thread.

The repair is very simple :
- Replace R56 (150 Ohms) That's it!

This resistor is in series with the LED part of the OPTO supposed to control Feedback and voltage regulation of the primary side of the Flyback.
R56 was open -> No feedback...