Computer Care Tech Tips

HP LaserJet 4200/4250/4300/4350:

An Easier Way to Replace the Swing Plate Assembly (RM1-0043)

The swing plate assembly, a small obscure assembly in the right rear of the HP LaserJet 4200/4300 series of printers, has recently become very popular. Why? One reason is that, obscure as it is, it has a very important job: to couple the printer’s main drive assembly to the fuser. The other reason is that if the fuser isn’t fully seated (which is unfortunately a common problem in this series of printers), it will “bounce” when the swing plate attempts to drive it. This can damage both the gear in the fuser and the gear in the swing plate. The standard remedy for this condition is to replace both assemblies (fuser and swing plate).

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In HP laser printers, the network configuration is stored on the network card (also known as the JetDirect card or EIO card), not on the Formatter board. Therefore, you need to reconfigure whenever a network card is installed or replaced. There are numerous ways to configure the network. Here’s what we recommend:

First, before attaching the printer to the network, install the card into the printer, power up, and then go into the printer’s “EIO x” menu (“x” represents the slot number that the EIO card is in). Menu structures are different in different printer models, so printing out the menu map may help you find this menu. Setup details also differ from one model to another, but in general, assuming that you have an Ethernet network (10Base-T or 100Base-TX) using a TCP/IP protocol (by far the most common), the basic steps are similar:

Tell the printer that you want to configure the network (“Configure Network = YES*” or something similar).

Select “TCP/IP” as the network type (you may also have to set “Configure TCP/IP = YES*”).

Select “manual” as the configuration method (other choices are “BOOTP” or “DHCP” – in some printers, you may have to set “BOOTP = NO*” and/or “DHCP = NO*”).

Enter 3 groups of numbers: IP Address, Subnet Mask, and Default Gateway. Each of these is configured as 4 bytes. For example, if the IP address is 10.1.1.24, “Byte 1 = 10”, “Byte 2 = 1”, “Byte 3 = 1”, and “Byte 4 = 24”, and these are the numbers you would enter. Ideally, you will have a record of the previous configuration, so that you can put in the same numbers. If not (or if this is a new installation), you can always assign new numbers. However, you can’t just put in any old numbers (in particular, if there are multiple devices on the network, you can’t use the same numbers as any of the other devices!), so it is best to consult the customer’s IT personnel at this point.

Now power down, connect to the network, power back up, and print a configuration page to verify the network configuration. In most cases, you’re done at this point, but some operating systems will have trouble finding a printer even after the address has been defined. So we recommend running HP’s “Install Network Printer Wizard”, which can be downloaded for free from HP’s website (www.hp.com) – just type “Install Network Printer Wizard” into the search window and you’ll find it. This program will step you through the installation of a new printer, and will also help the network find an existing printer. (NOTE: You can also do all of this with HP’s “Web Jetadmin” software (also available as a free download), but this is much more complicated, so stick with the software described above unless you are an IT professional.)

Among the most common problems that you'll see in the HP LaserJet 9000 is the false 13.20 error. It will come up during or immediately after the power-up sequence, before you even try to print anything, and you won't find paper anywhere in the paper path. As in any printer, this can be caused by a stuck sensor flag, but in the 9000, there are some other potential causes: a defective fuser or DC Controller board, or bad high voltage connections.

Because this error often comes up after installing a fuser, it's easy to assume that the fuser is the cause. But it turns out that the 13.20 error is much more often caused by the DC Controller, even when you get the error with one fuser but not with another. Here's why: the 9000 detects "wrapping jams" (paper wrapped around a fuser roller) by making an electrical connection to the conductive coatings on the fuser rollers. Early versions of the DC Controller board had a very narrow tolerance for this measurement, and natural variances in fuser conductivity put many fusers outside the acceptable range - even though there was nothing wrong with these fusers.

HP corrected this problem on later versions of the DC Controller, but many printers still have the older versions, and on these printers, it's hard to find a fuser that the printer will accept. To check the DC Controller version, print a configuration page and look at the "printer number" (a two-digit code ranging from 15 to 1C). If the second character is a number (5-9), the printer has an older DC Controller, which will be more likely to cause false 13.20 errors. On newer versions, the second character will be a letter (A, B, or C). All DC Controllers sold by Computer Care are the newer versions.

The bottom line is that by making sure that the DC Controllers are up-to-date in all of the HP LaserJet 9000 printers that you service, you can greatly reduce 13.20 errors and fuser warranties.