Yes indeed the plot thickens, for both of us :)

You first. There may (and I want to stress this operative word - may) be a very good reason why you want to use a power supply/transformer/converter that is the same OR very near the same as what the original manufacturer provided. It can get a little dicey. Not always. Sometimes. For one thing, has anyone else noticed the proponderance of these "power supply converters" in our present world? They literally are everywhere these days, which in part has helped them to attain somewhat of a generic status IE> when one goes bad, just go out to the mall or other place of mass retail, perhaps on-line, ebay, whatever, and get yourself a generic replacement. Many times this will prove successful, some times it won't and I really do not want to wager anything along the lines of a conclusive answer as to what the ryhme & reason is that explains why. In your specific case, "the 16 volt transformer" you referred to may turn out to be a good solution... or not. If you know of a place where you can find a 16 volt transfomer, you must make sure it can at a minimum meet two other requirements: 1) the capacity to source/provide at least 1.2 Amps ; 2) it must have the exact mating connector to the one that is on your scanner. Like connectors, these power jack/receptacle pairs are usually referred to in terms of male/female.... don't ask me why, this is not joke but the world of eletronics, especially networking, that involves all kinds of different funky connectors use the same terminology male cable & female receptacle. Usually (but not always), a device like a scanner will have a male prong type power jack, and the external power supply will provide a mating female connector. For power converters, this kind of connector/receptacle is loosley referred to as "mini RCA-style". Just trying to make sure that if you spend some $ for a new or used power supply/transformer, be sure to get one with a connector desgined to work with/mate to the receptacle on your scanner.

Now me. This little dialogue motivated me to quit proscrastinating with the scanner given to me over a year ago. It had belonged to my sister. About a year prior to this, one day it worked fine, next day it quit working. I originally suspected the external power supply went bad. At that time I spent a few hours on the web tracking down the manufacturers replacement part # for sis. At that time she procrastinated on ordering it. Within the next few months she bought a new PC, and a new combo printer/scanner, then gave the old scanner to me. About 2 hours ago I decided to renew/refresh the info search I'd done on this scanner 2 years ago. To my good fortune, my Scroogle searches found a couple hits from a forum that's grown up around customer complaints and problems with a wide array of HP products. In fact, I found several threads involving my specific model of HP scanner. I read them and discovered there was a consistent history of problems with this model relating to a badly designed circuit inside the scanner, this circuit of course is involved with the power provided to the scanner via the external power transformer. A few of the most frequently blown components (resistors, capacitors, ICs, transistors, etc) were mentioned in these posts. In particular the "R105, 30 ohm ceramic resistor" that several customers had reported they found "smoked", "fried", etc. So I started taking apart my scanner. Lo and behold I found my R105 fairly well fried to the extent that it's already flaked apart here and there. The potential remaining problem for me is that these forums did not conclusively say why this resistor frequently blew up on this particular scanner model, although there is some evidence pointing to a faulty design.

So the good news for me is, for now there is no need to worry about finding a replacement power supply. The less than good news is, there may not be a practical solution for getting this scanner fixed and back in operation :)

PS - for any curious, a suitable 30 ohm 5 watt resistor is not all that difficult for me to find and solder into the now-defective circuit card on my scanner. However, resistors in and of themselves generally do not go bad just of their own volition; they usually go bad to the extent of smoking, frying and blowing apart due to other components being defective in nearby circuitry. In the nearby circuitry on this one scanner PCB, there are easily dozens of other components to potentialy source and replace. Some of them are surface mount (read:tiny) and therefore not all that easy for the home enthusiast to replace.... it literally would be like orthodox laser surgery, but I won't go any further THERE :)