Symptoms: The printer powers up without errors, but when printing is done, only blank pages come out.

This is caused by several things, but on my printer, it was the DC controller board. I didn't know this, however, and replaced the HV power supply first which didn't fix the problem. The other reasons are almost all toner-cartridge related, so before you start tearing into the printer, swap out the cartridge.

If it still doesn't print, then the easiest thing to replace is the HV power supply. I don't think the case even has to be removed.

First, remove the screw that holds the arm which keeps the lid from opening too far. Open the printer cover all the way back. There should be four tall brass screws around the fuser - remove these. The fuser comes out by sliding it to the left, and then lifting up. Then remove the three small screws that hold the black plastic cover in front of the fuser. Remove the large screws that hold the power supply in place, and the two small ones that hold its connectors on the left wall of the printer. You may have to remove that black plastic facing on the left sidewall of the printer - it should just pop out. Then disconnect the top ground wire on the right side of the power supply, slide it out a little, and disconnect the connector below. Yes, installation is the reverse of removal, except that when reinstalling the black floorplate, there is a small plastic paper guide clipped onto the roller directly in front of the plate. Make sure you don't install the plate with that caught beneath.

Still doesn't work? Then maybe it's the DC controller board (which turned out to be the case on mine).

Remove the outer case of the printer. This is slightly tedious but fairly straightforward. With the lid open, remove the screws holding the top piece. Remove the screws at the bottom left and right sides of the printer. There is a small detachable panel(if you don't have an envelope feeder installed, that is) directly above the top paper tray - push straight down on it, and remove the screws holding the top behind it. Remove the screws at the bottom front. The side panels should slide off towards the back of the printer, allowing you to unscrew the last three or four screws at each side of the front cover. (You may be able to just remove the right cover - i didn't try that but feel free to experiment.)

The DC controller board is behind the large board with the memory slots. You don't have to remove this board. The entire right housing is a section that can be removed for access to the inner boards, so unscrew the top plate, noting where the fan goes, and the bottom screws, and just tilt the whole thing down. The DC Controller board is the small one all the way to the left of the other boards. Disconnect all the cables, and note that there is a pin connector beneath the board, so just pull it straight out once you've unscrewed and unclipped it. Then put the new one in, and put it all back together.

I am going from memory on most of this, so go slowly and keep track of everything. It's not nearly as hard as it looks at first.

You can find DC controller boards and HV power supplies at printerworks.com.