HP 4250 1/2 inch black bar

[cucuklotz]

Hi
Approx 1 in 10 prints come with a 1/2 black bar acoss the top of the page.I have replaced cartridge and cleaned and adjusted all contacts that come in contact with the cartridge.The band dosnt repeat. Please see attached.
Any help welcomed and appreciated. Thanks Andy


Sorry.Having problems uploading and attaching Example

[fixthecopier]

Re: HP 4250 1/2 inch black bar

On pages with the bar, is the text in proper plce or has it moved down the page any. Like reg slipping.

[cucuklotz]

Re: HP 4250 1/2 inch black bar

On pages with the bar, is the text in proper plce or has it moved down the page any. Like reg slipping.

Hi
Thanks for reply .Image is in proper place,
Thanks Andy

[fixthecopier]

Re: HP 4250 1/2 inch black bar

For it to be on the paper, it has to be written on the drum. Although I have never had one do this, I would swap the formatter with another and if that made no change, I would look at the printhead.

[cucuklotz]

Re: HP 4250 1/2 inch black bar

Hi
THank you for help.Can someone who knows machine possibly help,Everything registers correcterly as far as image registration.Black bar only happens once on the page(at top)when it happens.Please don't suggest I change the PRINTHEAD
THANKS ANDY

[fixthecopier]

Re: HP 4250 1/2 inch black bar

I do know a little. Been working on HP 17 years. To get on the paper, it has to be written on the drum. I have had printheads go bad and print black lines and bars. The formatter is what is sending the image. I would swap it first, it is easy. Swapping the printhead is easy, but I would crack it open and clean first. You can get a second opinion from Hytec board repair. They will give support to any caller.

[subaro]

Re: HP 4250 1/2 inch black bar

Hi
THank you for help.Can someone who knows machine possibly help,Everything registers correcterly as far as image registration.Black bar only happens once on the page(at top)when it happens.Please don't suggest I change the PRINTHEAD
THANKS ANDY

Fixthecopier is right in his suggestion and diagnostic. You are asking for help and he guided you to some possible cause, you can either ignore them or try another forum. Why then did you ask for the help. He was gratefull to give you a reply. I do know those machines too and would have given similar sggestions and more, but since you are rejecting suggestions, i would decline from giving any.
Now give your reason why you should not change the laser unit ?.

[cucuklotz]

Re: HP 4250 1/2 inch black bar

.
,Let me start off with an apology which is sincere and offered with the right motive.I am the least one of any tech forum I can promise you that'
I respect the generous help the techs on this site has given me over the years .Truth is I'm a taker and not much of a giver.I spoke out of turn and without knowledge.The help I can offer is very limited,and I know all on this and other sites have been patient and more than kind to me.

here is where my ignorance really made itself known.I have never heard the laser unit referred to as a printhead.If I had thought about the reply a little more deeply I may have made the connection,but as usual I reacted instead of taking time to respond.
Once again and with the utmost high esteem that I hold all on this site,I say IM SORRY and will do better in the future
Andy

[subaro]

Re: HP 4250 1/2 inch black bar

.
,Let me start off with an apology which is sincere and offered with the right motive.I am the least one of any tech forum I can promise you that'
I respect the generous help the techs on this site has given me over the years .Truth is I'm a taker and not much of a giver.I spoke out of turn and without knowledge.The help I can offer is very limited,and I know all on this and other sites have been patient and more than kind to me.

here is where my ignorance really made itself known.I have never heard the laser unit referred to as a printhead.If I had thought about the reply a little more deeply I may have made the connection,but as usual I reacted instead of taking time to respond.
Once again and with the utmost high esteem that I hold all on this site,I say IM SORRY and will do better in the future
Andy

Well glad that you cleared up what your misconceptions of the printhead was and can see why you did not want to hear of a printhead change. You made your feelings known and that's what count. All is well with me and your reply.
Yes, some manufactures refers or calls the laser unit printhead. Lexmark is one of them.

[fixthecopier]

Re: HP 4250 1/2 inch black bar

Sorry if my terms were confusing. When you work on everything, it is hard to keep the terms straight. Recent Xerox tech call, talking about drum....

me..the photoconductor [ricoh]

Xerox..huh?

me...you know, the image unit [konica]

Xerox...huh?

me...drum?

Xerox...ok, I got it now

[subaro]

Re: HP 4250 1/2 inch black bar

Fixthecopier is right in his suggestion and diagnostic. You are asking for help and he guided you to some possible cause, you can either ignore them or try another forum. Why then did you ask for the help. He was gratefull to give you a reply. I do know those machines too and would have given similar sggestions and more, but since you are rejecting suggestions, i would decline from giving any.
Now give your reason why you should not change the laser unit ?.

When i replied as in above i mentioned LASER unit instead of PRINTHEAD, as i was thinking that HP does not use the term printhead [on laser machines]and to refer it to the way HP describes and list it in their parts list. I thought just in case, let me use the term HP refers to their laser unit or the real proper term is LSU [laser scanning unit]. I think, just as the poster , many could have misconstrued the printhead as to inkjets and therefore seen the reply from fixthecopier as irrelevant.
So the poster did not reply eloquently in that regards to ask for further help. The poster is out of the penalty box and was a true man to correct what was seen as a harsh reply. The poster quickly explained himself and that's all it takes. Writing vs verbal in this instant connected world also requires a bit of patience.
My relatives live in good old england, and i can't get over my humor when they refer to the car TRUNK as the BOOTH.
edit: acutually, i think it is spelled boot.

[faxman28]

Re: HP 4250 1/2 inch black bar

Hi
Approx 1 in 10 prints come with a 1/2 black bar acoss the top of the page.I have replaced cartridge and cleaned and adjusted all contacts that come in contact with the cartridge.The band dosnt repeat. Please see attached.
Any help welcomed and appreciated. Thanks Andy


Sorry.Having problems uploading and attaching Example

hp4250_black_bar.pdfhp4250_black_bar_2.pdf


This is an old issue with this series of printer , if it happens on first page only of multi page doc, or first thing in morning/sleep mode, it is hv supply , contacts for dev voltage, charge roller. or toner cart. attachments from old hp bulletin from 2008 on what to check.

Doing some looking back when this issue first appeared , it looks like hv power supply or toner cart resolved issue. toner carts were reman or refill carts.

[fixthecopier]

Re: HP 4250 1/2 inch black bar

[ATTACH]33267[/ATTACH][ATTACH]33268[/ATTACH]


This is an old issue with this series of printer , if it happens on first page only of multi page doc, or first thing in morning/sleep mode, it is hv supply , contacts for dev voltage, charge roller. or toner cart. attachments from old hp bulletin from 2008 on what to check.

Doing some looking back when this issue first appeared , it looks like hv power supply or toner cart resolved issue. toner carts were reman or refill carts.

Good tip as I would have done the hv last simply because every time I have an issue with one, I get blanks. Just fixed a bizhub this morning that was shooting blanks by changing the hv. So, you go with what you know.

[Printerdude]

Re: HP 4250 1/2 inch black bar

Faxman28 is on the right track. If the customer are using remanufactured toner cartridges, I would try a OEM or at least a different brand remanufactured toner cartridge. Next would be the HV power supply.

[cucuklotz]

Re: HP 4250 1/2 inch black bar

[ATTACH]33267[/ATTACH][ATTACH]33268[/ATTACH]


This is an old issue with this series of printer , if it happens on first page only of multi page doc, or first thing in morning/sleep mode, it is hv supply , contacts for dev voltage, charge roller. or toner cart. attachments from old hp bulletin from 2008 on what to check.

Doing some looking back when this issue first appeared , it looks like hv power supply or toner cart resolved issue. toner carts were reman or refill carts.

Hi
Thank you for understanding and offering additional help.I will try another OEM and charge roller next week and if that dosnt work look to power supply

Once again thank you FOR putting up with my nonsense.
Andy