Laserjet 5SI Grounding Strap

[ChrisMN1]

I have a Laserjet 5SIMX.

On Page 6-55 of The Laserjet 5SI Service Manual it specifies that there is a Grounding Strap beneath one of the screws for the Registration Assembly.

On Reinstallation Instructions It states:

"3 Make sure that the grounding strap is under the left screw"

I can find no such strap.

Is this likely to be a problem? What does it do?

I would be grateful fr any comments.

[Valsimot]

To ground static electricity buildup from registration assembly the printer will work just fine without it.

[ChrisMN1]

Many thanks for your posting.

I decided to check it out with a multimeter and the Registration Assembly seems to be well earthed (grounded) even without the strap (tested relative to the earth terminal on the power cable)..

In fact, I'm just trying to find any possible solution to an ongoing problem I have with horizontal grey banding appearing on printed pages in the direction of travel.

I am using apparently genuine unused HP 3909 carridges - but, as these are no longer made by HP, I have to buy them on eBay and, although they look good, I don't know how long they have been stored or whether they might have deteriorated internally over time.

I have also tried cleaning the High Voltage Power Supply contacts for the cartridge and thought that might have helped a little, but the problem still recurs.

Any suggestions would be gratefully received.

[Valsimot]

Scan a sample page and post it here to be visible.

[ChrisMN1]

Many thanks for your help.

This is a scan of the PCL Test pages.

[Valsimot]

It could be a toner cartridge issue. You don't have many options, changing toner is one of them. All cartridges for this printer will be very very old and aging can cause print quality issues.

[ChrisMN1]

Many thanks for your posting.

You are being very helpful.

My chief suspect is also the toner cartridges - as you say, they are geting pretty old now,; and I think, perhaps, the cleaning blade in them may deteriorate with age, leaving bands of toner residue in place.

However, I try to keep this printer going as I've had it a lot of years and have replaced quite a few parts and generally nursed it along - so I've become quite attached to it!

I had wondered whether the problem might have been caused by bad voltages on the High Voltage Unit - but I can'r find any way of testing this, except for the Earth.

I'm probably clutching at straws with that idea though!

[ChrisMN1]

Just a further note on this topic.

I recently bought a C3909X compatible cartridge, not an HP original - and it's giving excellent results!

That means the problem can't have been with the printer at all but with the apparently original HP C3909 cartridges I had been buying on eBay.

It looks like the cleaning blade deteriorates over time and they can become unreliable.

However, in the past I've also had problems with compatible cartriidges, with some of them being of very poor quality, sometimes even dumpling tpner all over the printer!

If you can get a good compatible carridge though, all is well..