Not DEC related but still hoping for some help: Problems w/ LJ 4+ Printer

Grant Taylor cctalk at
Tue Apr 2 20:36:09 CDT 2019

On 4/2/19 2:47 PM, Ali via cctalk wrote:
> Yes, these guys were built like tanks. This one acts as a 4M now because 
> I added the PS module to it and it has local talk support. No duplexer 
> or extra paper tray though :(.

It was really a 4+.  I picked it up for $1 ~ $10 at a ham fest.  I then 
maxed the memory and added PostScript, thus turning it into a 4M+.

The duplexer was interesting.  It interfaced with the back of the 
printer in place of the fold down back cover.  The extra paper tray was 
part of the duplexer and where the paper flipped around.  -  I think it 
went under the tray instead of out the top, then came back up and feed 
like the normal expansion tray.

> I will have to keep that in mind. This paper was old - not sure how 
> old but it was in the tray when I found the printer on the side of the 
> road. So better to recycle it then risk it I think.

I'd be more worried about moisture with the paper.  But, sure, recycle 
it and replace it.

> It may be "hot enough". They are certainly warm. And I don't detect them 
> getting any hotter to touch as more printing goes on so this part could 
> all be in my head.

I don't remember the 4[M][+] ever getting all that warm.

The 4Si, that would get really warm.  Especially if you were using the 
job jogger, duplexing, and printing reams at a time.

> I can post it elsewhere if needed. It basically shows the picture getting 
> darker with subsequent printings.

I created an account, got logged in, and see both pictures.

I don't see any typical roller related defects.

> I am not sure how to quantify it but it looks solid on the drum. I will 
> have to repeat the test with a "cool" printer and see if it still looks 
> solid or not.


> Never thought about it but the extra toner (I assume not all the toner 
> is being transferred to every page of print) must get swept up back in 
> to the cartridge somewhere, no?

I am guessing that you have an HV issue, and the toner is not coming out 
of the cartridge.

> Not too bad. It is worth mentioning that the printer doesn't seem abused 
> in its old life either. Only 65K of prints...

It's a younging.

> Both of which should produce an error usually...

I thought so.  However, Dave M. indicates that HV problems /won't/ 
produce an error.

> I thought about bad toner but that doesn't explain the improvement with 
> time/prints. Or why it would go bad again after cooling down.

That doesn't sound like a toner cartridge issue to me.

> I would say 5 - 10 minutes. Once I get good quality prints the subsequent 
> pages all look great...

That tells me that it's not something mechanical.  I say that because it 
would be all the time.  (I guess a cold solder joint could be 
mechanical.  But I think that would present differently.)

> Thanks that was quick! I am pulling out the HV portion now to take a 
> look. If I understand correct the DC (LV) supplies everything else except 
> the engine. Those all seem to be working fine. Cleaning contacts is easy 
> (and cheap) so that will be my first fix unless I see something glaringly 
> obvious with the caps on the HV.

Yep.  He's retired.

> Thank you.

You're welcome.

Grant. . . .
unix || die

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