My HP 4250 is printing a black line every 7.5 ,

[d-davis1240]

My hp4250 is printing a black line every 7.5 inches accross the page, not on every page, but when i printed d 300 pages and 80 have black lines.,

[tonerspills]

Can you attach a photo for us to look at- most likely suspects would be the toner cartridge, transfer roller, or fuser. The compents I have listed would typically print multiple repeating image defects per sheet or paper, but 7.5inches is kind of an odd number, and by the number you listed- the defect is repeating about every 4 pages. Is that correct?

The 4250 is an older model. I have to replace alot of the fuser drive gears on these printers due to age and wear.

[d-davis1240]

ok so what happend in order, i thought it was the low toner cart. and replace that cart. it still did the line so i thought it was the fuser and replaced the fuser, still does it . below are the lines

[tonerspills]

From your picture, the lines appear to be spaced to far apart for it to be the transfer roller, and probably not the cartridge either. I would load the printer with blank paper, send a print job of about 10 pages, and open the top to make the printer jam, hopefully when the paper is under the cartridge. Since you say you replaced the cartridge already with a known working one, this would point to either the write unit or power supply if this line occurs before fusing. If this occurs after fusing and youve already replaced the fuser, then it is probably a worn fuser drive gear- i have to replace these all the time in 4250's. I carry about 10 of these gears around with me at all times.

RM1-0043-GRB Swing Plate gear- super easy to replace on some 4250's, just have to remove formatter cover and formatter, and hopefully there is a little hole where you can remove the screw and just change the gear.

Here is the whole fuser drive gear assembly- a little more labor intensive, and the printer has to disaamble to get the power supply out to replace it.

RM1-0043-N Swing Plate Assembly

[d-davis1240]

thank you i will try

[davidzuts]

The other thing I might try before replacing anything is a paper path test of 10  or 50 pages and post a copy of 1 of the pages from the paper path test that has the issue.  Hard to tell with your image but it appears there are lighter lines also appearing. I do not think this is a drive train issue, but rather a high voltage issue. If you get the lines on the paper path test, then I would just remove the power supply that sits below  the toner cartridge and then reinstall it. You could just have an issue of one of the contacts on occasion not making full contact causing an arch and causing the toner cartridge to produce the line.