Buying a used PX - Considerations?

[matroswe]

Late to game as always I'm now finally looking to buy a PX. I'm essentially looking for a used PX buyers guide.   
What should I be looking for besides appearance?
What things should I try?
Red flags?

[Derek Cook]

Hi.

I cannot think of much. The build quality is great, but there are reported problems of people having trouble with it booting correctly, so make sure you see any one you are thinking of buying, going through a boot cycle a couple of times.

And of course as it is a very interactive "knobby" synth, make sure that all knobs and switches are working smoothly

[matroswe]

Thanks for the input.
I got one before I saw your response, and I actually did do a couple of power cycles, tried a random number of controllers keys. Still works fine. I'm missing the ability to check the drive (as on for instance Kronos), but I have tried to add samples and it works.
The one I got has a serial number in the 400s, which apparently is fairly low, but it has been sitting in a studio, so the condition is great.

[Derek Cook]

Congratulations on your purchase. It is a great synth and a keeper that gives me the classic Prophet sound.

[fission99]

I own a very nice Prophet XL with a solid Yamaha case. Trouble is, I barely use it. I love the sound of the filters. I have tried to bring in samples but even though it worked, they didn't map the way I thought they should—probably just ignorant of the proper way to do it.

Anyway, what you should look out for is the motherboard going bad. I had to ship the unit back to California to get it fixed. They did so for free, but it I had to pay $250 or so for shipping. Then, later on when I got it back, & not played it for awhile, it decided not to boot on me. I found that the thumbnail battery in the unit had either gone bad or discharged. That is cheap enough and easy to fix & I did it. You'll need the new battery (~ $5 for a pack) & a USB keyboard to type in commands when replacing the battery. The procedure to do this is on this site, and I did it without trouble. I'm just worried that, since I've had it in the case for a bit, I'll go back & have to do this all over again!

I'm really on the fence with the keyboard. I love the sound but don't use the thing!