Me and printers. It’s just a never-ending tale of woe, lately.
Given the total failure of my new Canon machine (no, still no word from Canon support), I pulled my old Hewlett Packard machine out (it hasn’t yet been sold/FreeCycled) so that I could print some urgent and vital colour documents. The fact that I’ll also have to get out my old laptop to do this is an aside.
Upon putting it back on the shelf and powering up, the printer began its normal initialisation sequence. However, this didn’t seem to go normally and resulted in a rather unpleasant grinding noise from under the cover. Not good. A quick look revealed that the scan head was moving all the way to the right and banging against the casing of the machine. Repeatedly. It only stopped when it over-heated and cut out. Hmm.
A quick look at the HP support pages (which are generally pretty good) revealed that this can occur if the lamp is not reaching its correct operating temperature or is not bright enough. They give a set of possible causes, mostly related to the power supply. Well, since the machine is plugged in in exactly the same way that it has been for the last five years, I wasn’t convinced, but I checked anyway. Nothing doing.
So, as usual, Google is your friend and I found my way to this site. The problem with this sort of site is that you have to work your way through lots of discussion in order to extract a workable solution. Essentially, what was happening was that the scan head was looking for its zero-position marker and not finding it. This marker takes the form of a white strip on the underside of the glass, just to the right of the visible section. So, in order to assist others, here is a clear point-by-point method to fix the problem:
- disconnect the printer from the mains and USB.
- using a small screw driver, pry off the control panel cover from the end nearest the LCD display.
- using the screw driver, depress the tab found in the square hole (centre front) under the panel and slide the panel forward to remove it.
- unplug the ribbon cable from the circuit board on the underside of the control panel, making a note of its orientation as you do so (so you know which way to plug it back in later!)
- remove the two star screws exposed by the panel removal (one at the front, one right rear) and the screw near the rear left corner of the printer. (This third screw is described as being at the rear right on fixyourownprinter.com, which set me hunting around for something that wasn’t there for five minutes. Also, if you don’t have a star screw driver, a small flat screw driver might just work. Otherwise, head for your nearest electrical specialist for the correct tool – I got one for £1.26).
- look through the glass with a torch at the center front of the printer and you will see a U-shaped tab sticking down from the top cover that engages a projection on the main cover. Using a thin blade inserted between the covers (I used a very small screw driver which marked the case a bit, but I’m not that bothered), push the U-shaped piece gently towards the rear and carefully lift off the cover complete with the glass.
- you can separate the lid from the glass assembly by simply popping the hinges out (obvious when you look at it).
- carefully clean the glass on both sides, paying particular attention to the white strip. Yes, I know that it looks clean, but clean it anyway. Mine had a thin greasy residue across the entire underside surface which came away nicely using those tissue computer screen wipes.
- VERY carefully, using a cotton bud, clean the mirror that is underneath the lamp in the scan head assembly. Some users of fixyourownprinter.com said that they used an alcohol solution to do this, but I just used two clean dry cotton buds. Be very careful, as that lamp would be expensive to replace and is fragile.
- now to reassemble: place the glass assembly back on the printer, taking care to feed the ribbon cable back through the slot that it goes through.
- reconnect the ribbon cable to the circuit board on the control panel.
- now test that the printer works. Reconnect the mains (not USB yet) and switch on. Hopefully, it will initialize correctly. If it doesn’t, disconnect the mains, remove the ribbon cable and control panel, lift the glass assembly off and have another go at cleaning – you missed something and might need to use alcohol to get it really clean.
- assuming your initialization went well, turn the machine off and disconnect the mains again (better safe than sorry).
- replace the three star screws, taking care not to over-tighten (I actually haven’t tightened mine all the way in order to facilitate any future removal).
- replace the lid (the hinges just pop back in).
- replace the control panel by pushing it towards the back (taking care not to catch that ribbon cable).
- replace the control panel cover by inserting the front tabs first and then pushing down at the back (you may need to use a screw driver to gently help the tabs on their way).
- reconnect the mains and USB and you’re ready to go.
I shouldn’t be surprised if this trick doesn’t work for other scanners and all-in-one machines, although of course the assembly/reassembly will be different for every machine. However, it seems from fixyourownprinter.com that these instructions hold true for several models of HP machine.