Introduction: Repairing a Kodak 500 Photo Printer
My wife likes her little K500 photo printer, but one day it started printing only half of a photo. After an unsatisfactory session with the "help desk" in which they told her half of a heater was burned out, and for $80, they would "try" to fix it, I went looking on the internet to see if anybody else had run against this problem. They had, and a guy at fixya.com had a good verbal description of what he'd done to fix it. I muddled around for quite a while, and by trial-and-error got the job done. I thought it might be useful to others to have some photos of the process so they wouldn't have to do the trial and error thing I'd gone through.
I strongly recommend that you read completely through this Instructable before trying it, and especially study the photos. Some details are clearer in later steps because the machine is more completely disassembled in them.
Step 1: The Problem
Although the people at the Kodak help line told my wife the problem was due to "half of a heater" burning out, this did not make sense to me, and I thought it might be something else. It did turn out to be something else. Photos with this printer are made by film transfer to the photo paper, which requires firm contact between the dye films and the photo paper. This is achieved by a rod with two small levers/cams on the end that at the right time, is rotated so the cams push the dye film down onto the paper. The plastic cams/levers are small and thin, and the combination of time and probably exposure to heat makes them brittle and they split. The split in the cam/lever makes it so the lever cannot exert the force necessary to press the one side of the film down onto the paper, causing the "half-a-picture" fault seen here.
Step 2: Getting to the Problem
Begin by using a small size phillips screwdriver to remove the 5 screws shown circled in the photo. You'll also eventually need a high-quality jewelers' phillips head screwdriver, a small flat-blade screwdriver, and small, thin, needle-nose pliers. All the screws in this machine are similar, but different, so save yourself some grief and carefully label them or place them in small cups or trays so you can identify where they go.
Step 3: CAREFUL ! Just Crack Open the Top
The front of the case has tabs that can be carefully pried open once the screws are removed, but you cannot then just pull the top off. It will open about 1" at the rear of the case.
Referring to the photo, the circled items point out the two ribbon wires/connectors and one plug that must be released before you can go further. The photo shows the top open much more than is possible before the cables are unplugged.
Carefully use the small flat-blade screwdriver (a jeweler's screwdriver is fine) and slide the black locking piece slightly away from the white socket. This will release the ribbon wire and allow you to gently pull the ribbon wire from the socket. You can carefully use the small needle-nose pliers to pull the white plug from the white socket. Work from back to front--that is, pull the ribbon wire nearest to you in the photo first, then the white plug, and finally the ribbon wire in the back, this will allow the top to open a bit more with each one you pull.
There is also a green ground wire identified by the arrow in the center left of the picture. This will have to be unfastened, but you don't have to do it yet. One end of it is secured by a small phillips screw that can easily be accessed once the top is mostly loose.
Once you have the top off, lay it carefully aside, protecting it from damage.
Step 4: Release the Mechanism From the Bottom Case Half
Once the top has been removed, you now need to pull the mechanism from the lower case half.
Gently pull at the top, right above where the dye film cartridge is inserted and "wiggle" the mechanism back and forth and upwards. Some of the electrical connections at the other end of the mechanism may also need to have the case slightly pulled away so they clear, also.
Step 5: Unplug the Fan
The fan is held in its own black plastic piece at the back of the printer, and will come out when the mechanism comes out, but needs to be unplugged from the bottom PCB, as indicated by the circle in the photo. A gentle pull with needle-nose pliers will do the job.
Step 6: Loosen the Upper PCB
Using your small phillips screwdriver, remove the two circled screws and loosen the screw indicated by the yellow box. No need to remove this screw, just get it good and loose so you can pivot the PCB board to the rear.
Also in the photo are arrows indicating the black plastic locking pieces for the ribbon-wire sockets. The one in the right front of the photo is mounted horizontally, and to unlock it the tabs on the end need to be pushed away from you (oriented in the photo). When you reassemble the device, you'll be working from the other side, so remember to push the black locking piece away from you, into the socket, to lock the ribbon wire once it is properly inserted.
Step 7: Untension the Spring and Loosen the Tape
At the left side, outside the roller mechanism, is a small spring that fits in a small hole in the metal top of the mechanism. In the photo (sorry about focus), I'm using a small-blade screwdriver to pull the spring out of its hole (the hole in the circle). You can just let the spring gently loose, it is not tightly wound, and will not fly across the room or anything.
The arrow next to the circle indicates one of the two screws that have to be removed in the next step.
To finish this step, gently pull the tape that holds the wires (yellow and black arrow) from the metal case. Leave the tape attached to the wires, we'll use it to re-secure the wires when we're reassembling the machine.
Step 8: Remove Screws Then Metal Mechanism Cover
We're almost there!
Next step is to remove the two small phillips head screws that hold the metal mechanism cover on. Two of the screws that hold it are the ones under the PCB that we removed in an earlier step. Now it's time to remove the screw noted in the last step, which is next to the spring hole, and the screw shown in the circle in this photo.
It's important to have a good quality, sharp phillips-head jeweler's screwdriver for this step, because these screws are really tight, and you'll strip the heads, or even break your screwdriver, if you try to use a cheap jewelers' screwdriver.
By the way, in the yellow box in the center of the photo is the screwhole for the green wire screw terminal mentioned earlier. It's much easier to see here.
Step 9: The Culprit Revealed !
Once again, I must apologize for my focus problems, but in this photo, with the cover off, you can clearly see the split cam/lever that is causing our problem. When the shaft rotates, the cam just slips inside it, rather than rotate with the shaft.
Step 10: Another View of the Problem
I included this photo to help orient you as to the location of the problem area. It is on the end of the machine into which you insert the "ink" cartridges, with the front, or side from which the pictures come, facing toward you.
Step 11: End View of the Problem Area
Here's a final view before we start fixing it. Note the green plastic piece which you might recognize as the tab you push to release the "ink" (dye film) cartridges when you change them.
Now let's get it fixed!
Step 12: Roughen the Shaft Next to the Cam/Lever
This printer is a precision and delicate machine. You don't want any foreign crud in there. So I used some 3 inch square Post-It notes to protect the area under the surgery area. First step is to roughen the metal shaft immediately next to the split cam/lever with some emery paper. Exact grit isn't all that important anything between about 220 and 400 ought to be OK.
When you've got visible roughening on the shaft, also roughen the surfaces of the plastic cam/lever.
Carefully blow, or vacuum out any grit, or other crud that falls on the paper.
Step 13: Close Up the Split
My mentor on Fixya.com said he used thread to wind around and close the gap, but another guy on the blog said he used wire. Wire sounded better to me because you can twist it and it will keep its tension--with thread you have to carefully maintain tension as you wind and secure it.
I used a single loop of copper wire, about #20 or so, and using the needle-nose pliers, carefully twisted it until the gap was almost completely closed. I didn't want to twist the wire off so I didn't over-tighten it. When done, I trimmed it as closely as I dared and pushed it over to protrude as little as possible from the surface of the cam/'ever.
Step 14: Clean Everything Up
Using rubbing (isopropyl) alcohol and a cotton swab, clean everything--shaft--cam/lever, and copper wire with a good swabbing. Allow to dry thoroughly.
In this photo, I had not yet installed the wire, but I did swab again after I did. Gotta be clean or the dope won't stick!
Step 15: Some Additional Protection
The next step is potentially very messy, with glop that will completely ruin your printer if it gets into the wrong places. So I added a bit more protective Post-It-note, taping it in place to hold it.
Make sure that anywhere the dope can drip, run, or otherwise go where it isn't supposed to, is protected.
Step 16: Mix Up a Small Batch of JB Weld
Carefully mix a batch of fresh JB Weld. (Probably other brands of epoxy will probably work, but JB worked for me). I used two large-size paper (Gem) clips--one to mix, and one partially straightened, to apply it.
Step 17: Cover the "Wounded Area" With JB Weld
As mentioned, I used a straightened paper clip to dab on JB weld all over the repair area, including packing it into the remaining split, on and over the copper wire, all over the plastic cam/lever, and onto the roughened part of the shaft next to the cam/lever.
One place you do NOT want any JB Weld is on the shaft where it goes through the frame--locking the shaft so it will not turn.
You may find, as I did, that the JB Weld wanted to sag and "bloop" downward, while I wanted it to stay evenly distributed around the shaft. To achieve this, turn the unit upside down at about 10-minute intervals, until the epoxy hardens enough to stop sagging. I also set the unit up on its end with this area down, to let the epoxy run toward the cam/lever, being VERY CAREFUL to observe that it was not running to the end of the shaft where it meets the frame.
Allow your fix to dry overnight, at least. Nothing to gain by rushing it.
Step 18: One Reassembly Trick
As I reassembled the unit, I found this black plastic piece loose. I hadn't paid much attention to it as I disassembled the printer, and had a heck of a time figuring out where it goes.
It goes at the top of the front of the case, as shown. (Sorry for clutter in background of photo). The key to figuring it out is to find the little black tab right in the middle of the piece. This tab is the lock for the front door of the unit, that "clicks" it into place and holds the front door closed. Orient this little tab down, and to the front of the printer, test the door to make sure it clicks shut, and you've got it installed right.
Step 19: Success !
I'm pleased to say the printer worked perfectly on first try after disassembly and has produced about 50 perfect photos so far. I'm not sure how permanent the fix is, or if another part will break, but so far, we're about $80 ahead of the curve--(actually a lot more than that, because we were going to buy a new printer before putting $80 into repairs for one that wasn't all that old.) Hope Kodak's next generation of photo printers is a bit more robust!