asked Jul 24, 2011 at 1:29pm
Hp HP DeskJet Plus

HVPS for HP LJ4 - RG5-0969 ok, or RG5-0513 needed?

Two questions...

Q1: the RG5-0969 high-voltage power supply for the 12ppm LaserJet 4 Plus and LaserJet 5 looks identical to the RG5-0513 HVPS for the 8ppm LaserJet 4 and 4M. So, will an RG5-0969 HVPS work in a LaserJet 4 and 4M, or is an RG5-0513 needed?

Q2: this LJ4 printer (which I bought new back when dinosaurs roamed the earth), recently started sporadically printing very faint pages. Sometimes the print looks perfect, sometimes it is so faint that it is barely visible, and sometimes it's somewhere in-between. One test page started out with light grey print at the leading edge of the page, which transitioned to dark grey in the middle of the page, and nice black print by the bottom of the page. My uneducated guess is that the HVPS is having trouble firing up. Does that sound right?

First try a known good toner cartridge.
by dmzcompute on Jul 24, 2011 at 4:35pm Add comment
Did that already.
by geeksalive on Jul 24, 2011 at 5:51pm Add comment
They're probably interchangeable. No reason for them not to be. A lot of HP's p/ns for newer models change, but they fit in the older models.
by moe on Jul 24, 2011 at 8:57pm Add comment
Thanks, Moe. Does HVPS sound like the most likely culprit, to you?
by geeksalive on Jul 24, 2011 at 9:10pm Add comment
No, I would agree with dmz about it being a toner cartridge. Usually when a client calls with a problem like this, we suggest trying a toner cartridge before they have to pay for the service call. Can't tell you how many times I've gone out to a client only to find the toner cartridge is the culprit. Just happened again last week and they swore they put in a "new" cartridge. I have trouble believing it's a HVPS, but that would be the next thing to try as long as we know that you tried a "Known Good" toner cartridge. - moe
I replaced the RG-0513 HVPS with an RG-0969 (purchased on eBay), and the LJ4 is working well again.
by geeksalive on Jul 29, 2011 at 6:50pm Add comment