550 2nd BTR Assembly
Welcome back to the lesson in patience which we bravely began two months ago. In that first article, we took the 2nd BTR assembly of a Color 550 almost all the way apart. Not an easy procedure, but doable given enough time and patience. Now we’ll soldier on and finish the procedure, as we lift the core of the unit out and replace the consumable parts within. Afterward, we’ll also talk about the four versions of the units within the DC250 style, with a close eye on what’s the same and what’s different about them.
Photo #10: Extract pivot shaft out front end
Let’s start where we left off in the procedure. After you extract the pivot shaft through the front end of the unit (step #15 in the previous article, see photo #10), you can now get to the most important components in the assembly, which are usually sold in a kit (DC700BTRK): 2nd BTR Roller, Cleaning Brush, Cleaning Blade, and Wax Bar. Below is how the procedure continues:
Photo #11: Lift the transfer roll and cleaning assembly’s front end upward to get the assembly out of the base of the unit.
16. Lift the transfer roll and cleaning assembly out of the body of the unit. You can lift the front end up and out first (see photo #11). Be gentle with the fragile foam gasket strip on the front end, which needs to remain intact. Also watch the Mylar recovery blade, which is along the right side of the assembly, next to the transfer roll.
17. Vacuum out the waste toner in the body of the unit. (see photo #12). Again, be gentle with the Mylar recovery blade.
Photo #12: On the left is the body of the unit where waste toner will be found. On the right is the transfer roll and cleaning assembly.
18. Remove the front end cover from the transfer roll and cleaning assembly (1 screw, see photo #13). With this cover off, you can remove the transfer roll, the cleaning brush, and the wax bar assembly from the metal framework of the cleaning blade assembly (see photo #14)
Photo #13: Remove one screw from front end plate of transfer roll and cleaning assembly
Photo #14: Components of the transfer roll and cleaning assembly
19. Replace the wax bar. The old wax bar’s metal plate is adhered to the rest of its framework by double sided tape. You’ll need some tape to stick the new wax bar back in place. Be gentle with this piece: sometimes they crack, which is OK as long as all the pieces remain in place on the metal plate. This wax bar helps lubricate the cleaning brush so that it lasts longer.
20. Remove the tension springs on the cleaning blade assembly (one at the front end and one at the rear end, see photo #15)
Photo #15: Blade tension springs
21. Pivot the cleaning blade assembly open and remove the 2nd BTR cleaning blade (2 screws, see photo #16)
Photo #16: Removing the cleaning blade from its metal assembly (1 of 2 screws shown in photo)
22. Reassemble everything. Take your time and make sure things fit right against each other, but don’t force anything. There are a few places in this unit (especially near the cam plates of the transfer roll) where delicate parts are in harm’s way. If something is not quite in the right spot and you push too hard against it, you might damage some of these parts. Refer back to the disassembly procedure and the photos to help see how everything should go. Also make sure to pay attention to which screws go where (which are machine thread and which are plastic thread is important).
Now, let’s review the four versions of 2nd BTR assemblies within the DC250 style:
- DC250 version: 059K45987 / 059K88420 (for: DC240/DC242/DC250/DC252/DC260, WC-7655/7665/7675, WC-7755/7765/7775)
- 550 version: 059K68395 (for 550/560/570, C60/C70)
- 700 version: 059K55905 / 059K78323 (for DCP 700/700i/770)
- J75 version: 059K79314 (for J75 / C75)
The 2nd BTR roller, brush, blade and wax bar are all the same for the 550, DC-700, and J75 versions. Only the DC250 version uses different internal parts. Note that the DC5000/7000/8000 are extremely similar to the 700 or J75 version, with the exception of the cleaning blade, which is the only unique piece.
The procedure showed a 550 unit, but the job will be similar for all of these, with a few slight deviations. The procedure should suffice to get you through rebuilding a 700 version or a J75. The DC250 version is supposedly easier to take apart.
The gears on the rear of the unit include a pair of gears for the transfer roll drive and another pair relating to the cam drive. Below is a list of all the varieties of each of the gears for identification purposes:
DC250BTRDG – 2nd BTR Roll Drive Gear 39T (at rear end of roller) (fits all versions)
DC250BTRDIG – 2nd BTR Roll Drive Idler Gear (17/43T) (fits DC250 version only)
DC700BTRDIG – 2nd BTR Roll Drive Idler Gear (24/44T) (fits DC700, 550, & J75 versions)
DC250BTRCG – 2nd BTR Cam Gear (Retract Gear) (67T) (interchangeable across all versions)
DC250BTRCIG – 2nd BTR Cam Idler Gear (30/28T, Black) (fits DC250, DC700, & J75 versions)
550BTRCIG – 2nd BTR Cam Idler Gear (30/24T, White) (fits 550 version only)
For the front end of the unit, we’ll only show the 550 version, as the gear layout is the same for the DC700 and J75 versions (note that the DC250 version has no gears on the front end)
DC250BTRFC – 2nd BTR Front Cam / Actuator (fits all versions)
DC700BTRG40T – 2nd BTR Front 40T Gear (fits 550, DC700, & J75 versions)
DC700BTRG16T – 2nd BTR Front 16T Gear (fits 550, DC700, & J75 versions)
That’s a wrap. Hopefully the procedure makes tackling one of these units less intimidating, as well as less time consuming. Happy repairs folks!
