HP DLT - How to Rethread a Dropped Leader in a DLT40, 70 or 80
This document details how a dropped leader many be manually rethreaded.
Media cartridges that have been dropped or damaged can cause the Tape leader loop to be "sucked" back into the cartridge.
Figure 1: Tape leader loop
1 - Tape leader loop
When this is inserted into the DLT drive, the leader that would normally drag the Tape leader loop into the take up spool cannot find it, because it has disappeared inside the cartridge.
When the leader is lost or dropped, the leader is to be found wrapped around the spindle of the Takeup Spool.
HP is not liable for any damage done to the drive. Customers, who undertake this process, do so entirely at their own risk.
Removal of shrouds or covers will usually invalidate the warranty upon the tape drive. Therefore, this process should usually not be attempted if the drive is in warranty. If the drive is in warranty, then contact your local call center for further advice and a possible unit exchange.
Click here for a list of call centers
If an out of warranty exchange is arranged after this process has been abortively attempted, then all parts of the tape drive must be available for exchange. Penalties may be applicable if an exchange drive is incomplete or physically damaged.
Be fully aware that opening your DLT drive will invalidate your warranty unless you have specifically agreed to do so under the supervision or express permission of HP.
All Tape devices contain printed circuit assemblies that are static sensitive, ensure that you take the proper precautions beforehand.
In addition, the leader within the drive is sensitive and you must not expose it to contamination. Always wear nylon or latex gloves when handling it.
Opening the Tape drive
Ensure that the power is turned off. If the drive is mounted internally to your system, remove it. If it is an external drive, then dismantle the drive accordingly:
Remove the shroud by removing the four screws on the base and sliding the shroud forward.
Two further screws in the underside mount the power supply. Remove these.
The drive is held in the cradle by two screws on each side. Remove these screws.
Disconnect the SCSI and power cables and slide the mechanism forward and free of the chassis.
Opening the drive
Be careful not to introduce any dust into the head area while the cover is removed.
For DLT80 drives
Lift rear release tab slightly.
Gently press front locking tabs with a small flat screwdriver.
Lift dust cover.
Figure 2: Removing DLT80 cover
1 - Dust cover release tabs
2 - Warranty seal (warranty is void if seal is broken)
3 - Small flathead screwdriver
|| Rear release tab is under the warranty seal.
For DLT40 and 70 drives
Unclip the dust cover catches.
Figure 3: Dust cover catches
1 - Dust cover catches
Re-attaching the leader
The picture here is of a DLT70, but the principles apply equally to a DLT40 and DLT80. The leader is shown in red. The Buckling arm is shown in blue and the tape loop is shown as a green line. Remember that you will need clean gloves to handle the leader.
Figure 4: DLT70 Leader
1 - Hook
2 - Buckling arm
3 - Takeup spool
4 - Head assembly
5 - Solenoid
As mentioned earlier, when the leader is lost or dropped, it is to be found wrapped around the spindle of the Takeup spool.
Drag or feed the leader through the tape path until it reaches the Buckling arm area. This is easier than it looks, especially in the DLT40. Be very careful when pushing or feeding the leader past the head assembly, the heads are extremely
Defeat the door catch by pulling the Solenoid arm away from the door flap (or raising the operate handle), insert your finger (shown in orange in Figure 4) through the doorway and gently push on the Buckling arm to re-engage the hole in the leader over the hook of the Buckling arm (see Figure 5).
Figure 5: Tape leader and Buckling arm
1 - Tape leader end
2 - Buckling arm
When refitting the cover, be careful not to trap the head flexible printed circuit strip. Discard the latex gloves.
Refit any shrouds.