Fixing Paper Tray Latching Problem
On Okidata LED Page Printers
Okidata OL400/600/800 series
Okipage 4/6 series
and similar models
Okidata LED page printers have been attractive for home use because of their compact size and inexpensive price. However, one exasperating problem common to these models is a paper tray latching mechanism that sometimes doesn't hold when the paper tray is closed.
When the paper tray is pushed all the way in, the latching mechanism clicks and the tray is locked when you take your hand away. To release the tray, press in until the latch clicks again, and the tray pops out forward when you release your hand pressure.
At least that's the way it's supposed to work. The problem is the latch doesn't always catch and the tray pops right back out as soon as you take your hand away. To fix this problem, follow the procedure below.
Remove the paper tray and turn the printer upside down. Along the side rails that the paper tray slides into, and about two-thirds of the way from front to back, notice a cutout in each rail. In each cutout is a 2-1/2" long finger, anchored at the back and extending forward. At the front end of this finger is a nub that protrudes inward toward the paper tray. This nub can be easily seen in the closeup view (note the paper tray is removed).
When the paper tray is inserted, this nub follows along the side of the paper tray until it encounters a heart-shaped island (see diagram). As the tray is pushed all the way in, the nub is forced up and over the heart until it snaps into the crook of the heart. The tray is now locked. When the tray is pressed in again, the nub, which is on the end of a spring-loaded finger, drops out of the crook and the tray can be removed.
The latching problem occurs because this nub doesn't press far enough into the heart-shaped track on the paper tray. This may be due to manufacturing tolerances, wear on the plastic parts over use, or a combination of both. The solution is to tweak the finger sideways slightly so the nub mates with the paper tray's track more closely.
There is a gap between the outside edge of the finger and the case. You can tweak the finger inward slightly by jamming a shim into this gap.
For a shim, I used the stick from a Q-Tip(tm) cotton swab, cut to a length of about 3/4". The center portion of a round, wood tooth pick will also work. Wrap the stick with a piece of plastic electrical tape about 1/2" to 3/4" long. This increases the diameter of the shim for a better fit, and also provides a slightly cushioned surface to the shim that will hold it in place better.
Insert shims on both sides. A shim, wrapped in blue tape, can be seen in the closeup view. The finger tapers slightly and is narrower at the front end, so insert the shim at the front of the cutout and slide it back in the gap until it fits snugly. Be careful not to overdo it, but slide it back firmly enough that the paper tray now latches reliably.
Jan-20-2001, by Dan Goodell
Note: the author is not associated in any way with Okidata, Oki Electric Industry Co., or Oki America, Inc.