HELP! VHF not charging.

[Appleyard]

The VHF is an sx-micro 90..I bought a suitable mains charger as the original seemed to have gone AWOL. ,however it is not charging the set. In the photo,I have taken the battery off ,and the contacts are visible, there is no reading at the contacts (I m using a meter) .I have a reading at the jack plug and I get continuity between the centre "post" of the socket and one of the contacts ,but no continuity between the outer "ring" of the socket and the other contact,so there seems to be a break somewhere in this circuit.I tried cleaning the ring but still no luck. I have been able to charge the battery by connecting it to the mains charger using croc clips and bits of wire ,but would prefer to be able to plug in and charge Any bright ideas folks??

 

[fluffc]

Some thoughts...

A 'suitable' charger? Did you buy the proper one for the vhf: Does it have enough power to do the job; check the mA rating against the original.

You won't always get a direct reading through the VHF to the battery connection as it is likely there is some form of control circuitry inside.

 

[Appleyard]

Yes..it,s 12 V Dc ,200ma as stated in the operating manual,which I have. Surely if I plug the charger in I should be able to get a reading at the contacts ? Also as I said,I can charge the battery pack directly via croc clips etc.

 

[fluffc]

You won't necessarily get a reading because of the internal electronics.

One check, does the VHF power up with the charger connected (no battery connected)? This will check that the connection from the charger is okay.

If it's dead, then it is possible that there is a problem with the socket. This is a known weak spot, and is likely to suffer from either corosion on the contact, or a broken solder joint on the PCB.

I repaired a handheld VHF by replacing the power socket with the (unused) external speaker socket, as they were both the same design and could be unsoldered & resoldered without problems. [Only do this if you're confident of your fine soldering skills, and are prepared to write-off the radio if it goes wrong]

 

[jerryat]

I never use the charger on my SX90. Just plug a 12volt supply directly into the socket on the right hand side of the unit (looking from the front) This will fully charge the battery perfectly well. Do NOT use the socket at the top which is for a different purpose.

If you are stuck over the polarity of this cocentric plug, PM me and I'll check it out for you.

 

[Appleyard]

Yup it would seem to be ,from what you say,a faulty socket as it does not power up with the battery removed. There is also a seperate socket for external power..it does not seem to work either. I will have a further look at the socket and try to trace the fault. Thanks for your help.

 

[Appleyard]

Hi Jerry it would seem to be the actual socket which is faulty..Re the polarity..I have checked it and the centre pin is +ve (as far as I can tell !!) as it charges the battery pack when I hot wire it + to + . Thanks.