MX7001N F2-40

[gwaddle]

I have an mx7001n with an f2-40 code. According to the book it should either be a toner cartridge, the toner empty sensor harness or the pcu pwb. I looked at the history and it had also recently had an f2-41 which is the cyan toner empty, so i don't think it's the harness. I'm ordering a pcu pwb unless someone has a different idea. I also replaced the toners which were showing empty. Help please.

[OMD-227]

F2-40 on either a C-Dragon or Venus machine is quite common. Most of the time its caused by the Black drum causing the main charge to short (ground). It happens mostly when the drum is near the end of its life, especially when the ends of the drum are chewed out. The exposed drum substrate surface tends to pull dev and can arc the charge unit. Pull out the waste toner, pour some out and put your magnetic tip screwdriver in there. If there is dev in the waste toner, you definitely have a worn drum, which should be replaced. Do the drum seals while you are at it. Make sure the firmware is current. This helps alot of problems on these series machines, especially an overtoning issue.

On a less common note, but which I have seen as well, it could be toner level sensor within the black dev unit. This is located on the hopper section, on the top of the dev unit. I have had a few of these just go bad, and the machine runs itself out of toner, as the sensor thinks the amount of toner in the hopper is OK, and refuses to rotate the toner cartridges to refill it. If you run a continuous full coverage black page with the toner door cover tricked, you will see the toners start to rotate if the sensor is good. If the toners do not rotate, check the black dev unit/replace.
Also, confirm the DV and MC charge bias voltages in sim 8-01 & 8-02 are good, matching the values against the sticker on the HV board.

As for the F2-41, if you are using the old part number for the CMY grid units, you can definitely get this error as Sharp found a problem with the shape of the sawtooth. The old sawtooth and MC unit combination, with any dew/condensation inside the machine, would leak charge, causing either F2-41, 42 or 43 for CMY. The black MC never had that exact problem as it is a different shape. I will attach a sample of the changes/new part numbers. As for the CMY drum units, just use the regular MX27 drum unit. All you need to do is just change the green MC cleaning arm as it is a different length. Dont bother rebuilding a C-Dragon or Venus color drum unit each time, we just use the Pastel/C-Jupiter drums. They work fine.

In all the F2 codes I have seen on these machines, none were ever caused by the PCU board.