Service manual

Important

MECHANICAL ISSUES

Keyboard:

Originally, three different types of screws were used in the ASR keyboard base pan 832s,

two 6-32s into main board heat sink, and self-tapping into the extrusion. The 6-32s were eventually

changed to

8-32s,

so that there are now only two different types of screws.

Keyboard:

On early units, you may break the disk drive bezel when removing the disk drive from the

unit. The wheel cover was modified on later units to prevent this.

Keyboard: If the mounting posts for the wheel brackets break, call ENSONIQ for a new wheel cover

that has the posts reinforced.

Keyboard: Early units may have buttons sticking or keys clacking. To make sure that buttons don’t

stick on later units, a M4xlOmm hex head set screw was added to the extrusion rail that the

keypad/display board mounts to locate the keypad/display board properly. Don’t remove this set screw.

Rack:

On Rack units, use a drop of Loctite on screws that hold the circuit boards in place if nylock

screws are not used. Nylock screws have a patch of nylon on the threads for greater holding power.

Rack: On ASR Racks with serial numbers between 10000 and 10500, the rack ear screw PEMs (screw

mounting standoffs) may fall inside the unit.

ASR Case (Avoid Stripping Screws)

Be careful when assembling or disassembling any part of the ASR. Avoid over-tightening screws when

repairing a unit! Use no more than 8

incMbs

of torque when tightening any screw. The ASR case is

made of aluminum extrusions and steel. Some parts are held in place by screws that

tighten into aluminum mounting rails that are part of the case. When replacing any of these screws, it is

possible to over-tighten the screws and strip out a hole.

High-Retention Force Connectors (Repair Technicians Label)

Inside the ASR is warning/information label just for you. We wanted to let you know that we use high

retention force connectors in the ASR. This means it is very difficult to remove a connector by just pulling.

We recommend the use of a scribe, screwdriver or similar object when disconnecting cables. Watch out for

them, and please don’t pull on the wires!

We have found that some units develop further problems once a module has been changed. This

may be

a result of improper handling of cables. We suggest removing all cable connectors using the angled end of a

scribe (see Figure 5).

Figure 5

Correct tool for removing cables

Scribes can be found in the following catalogs:

l Techni-Tool catalog part number 400PR144.

l Newark catalog part number

76-

15 10.

ASR Service Manual