My WD external hard drive I bought back in 2008 decided to just stop working. I plug it into my computer and it does nothing. It doesn't make any sound. The only thing it does is the power light blinks on and off. I have a SATA adapter that I plugged into it and the power source on that does the same thing...the light blinks on and off. I was told by a friend to replace the PCB. I am looking on eBay for one and found one with matching specs, model number, and that etched board number. Is that all that needs to be the same for it to work? Does the date, DCM, and S/N have to be the same too?