unknown

asked Apr 30, 2004 at 3:53am
Hp HP Color Copier 120

HP 8500 Streaks

Hi,
I have a very strange HP Color LaserJet (8500) problem here, maybe someone has already solved that.

It prints horizontal small streaks on the top end of an A4 page. It is an 8500 so it takes the A4 page sideways. They streaks are between 2 and 5 mms long, quite short errors. They may be any color you like. It does NOT doe that on A3 pages, no problems there.

It does not do that on every page, in fact, I cannot predict this happening. It gets worse now, it's about 50 of 120, the customer says. Formerly it was just 2 of 100. It's either green or sometimes blue.

I could not find any damaged part yet. The transfer and fuser have ~30 percent left, and the drum kit is to be renewed today.

I have told the customer to print the endless self test config page some 100 times, so I can see wether it comes from the printer itself or is externally caused.

The printer has seen ~800.000 pages in 4 years (!), all color. They print german tax documents for companies, every time some 120 pages * 20.

My guessing is defective memory.

Another issue is that it sometimes forgets a page in large documents. When you print 5* 120 pages, it prints 4*120 perfectly, and in the fifth it makes page 107 twice and forgets about 108, continuing with 109 directly. Strange.

I asked Moe but he had no real idea yet.

Thanks a lot for any help,

Bye,

Carsten

P.S- I solved the 4500 (prints only black) recently, it was a defective clutch on the left hand side, the one that moves the transfer belt up and down. If it does not do that properly, the gap between the drum and the transfer belt gets to large, and then, only black toner is transfered. There you go :-)