Pc not recognising usb cable from pm4

[wilfy]

Hi All,
I have a concept 2 model D PM 4 that i have had for 8 years which has been superb,lately through work etc, we have not used the Erg as regular as we used to,hence i keep having to recharge the rower with the usb in to my computer,this has had to be done several times over the last 6 months.I am now back on track with regards to getting back on the rower i went to use it last night and the pm4 was blank,i plugged in the usb to my laptop and the device was not recognised i then tried another pc and the same device unknown message displayed.
I have put batteries in for the time being,and ordered a new usb cable in case it is that,but i am wondering if it is a driver issue or could it be a problem with the pm4 unit, i am really stumped and do not want to keep putting batteries in when i can charge it with the cable.

Any information will be appreciated.

regards
Alan(Wilfy)

[Citroen]

Try plugging it in to a mobile phone charger.

There have been cases where folks have torn the USB-B socket off the circuit board. So you may want to open the PM4 and do a visual inspection of that (and maybe reflow the solder on it).

[Carl Watts]

The pre 2007 versions of the PM3 and PM4 had USB socket issues. Due to the large thermal mass of the socket the temperature profile of the reflow soldering process didn't really fully melt the solder and the joint was not full strength. Anyone forcing the polarised lead into it the wrong way around tended to remove the socket from the board. I have repaired dozens of them now and either this or some oxidisation on the contacts due to age and or it never being used (the wiping action of inserting the lead now and again helps clean the contacts) is usually the problem. In rare instances battery leakage gets into this area of the board and takes out the USB comm's.

If a visual inspection of the socket inside after taking out the 4 rear cover screws looks okay, try a different cable on a different PC.