Question about HP adaptor failure

[Beemer2]

I use my HP Ipaq H5550 to tune my acoustic piano. The software will only run on this model so I need to get it working.

The HP charger is 120/240V to 5V dc 2A. Recently it stopped charging and the iPAQ battery is completely flat. On checking the charger output voltage I noted that it was only a few millivolts d.c. However on switching my UT70D meter to a.c. it reads 3.5V.

Can someone explain to me why I see an a.c. voltage at all?

Unfortunately this is one of the friction welded plastic cases and it probably is too much trouble to open it.

Ian

 

[BradtheRad]

On checking the charger output voltage I noted that it was only a few millivolts d.c. However on switching my UT70D meter to a.c. it reads 3.5V.

Can someone explain to me why I see an a.c. voltage at all?

Probably some diodes failed as short circuit. Maybe some failed open. Consequently AC is getting through to the output. Maybe with a weak DC component.

Unfortunately this is one of the friction welded plastic cases and it probably is too much trouble to open it.

I have used my hacksaw to open up adapters. Plastic isn't so bad to cut through. Take care not to slip and ruin components inside.

Also try compressing it in a vise, carefully, on the slim chance the seam will cr-a-ck open.