Welch Allyn 12000 User manual

Section 17

This manual is now part of the Traditional Instruments Service Manual

Binocular Indirect Ophthalmoscope

B. I. O. Model 12000

Model# Model Name Section Page

12000 B.I.O. 1 3 -7 74101 Battery Pack 2 8 74141 B.I.O. Wall Bracket 3 9-10 All Required T ools 4 1 1 All Figures 1.7, 1.10 A&B 5 12-13

Special Instructions for B.I.O. Service

Clean all returned items by wiping with a solution of 10% Clorox/90% water. Do not use alcohol or other chemicals to clean to B.I.O. Inspect the unit, especially alignment prior to disassembly . Duplicate (if possible) customer problem.

Important: Check alignment before and after service.

1. Put B.I.O. on head.

2. Look at object held in hand, arms length. If the image appears as a double image, then the unit is misaligned. The B.I.O. unit must be evaluated on laser alignment equipment at Welch Allyn. Return to Technical Service Dept. for evaluation and or repair . Therefore, proceed with repairs only on units with good alignment.

Disassembly of Model 12000 B.I.O.

Refer to Figure 120103 in Repair Parts Catalog

Abbreviations used in text and parts list:

nn nn

1.1 Lamp Remove lamp cover .

CM EM CMH IM VS IS BIS

Central Mirror Eye Mirror Central Mirror Holder Illumination Mirror Viewing System Illumination System B.I.O. Sub-Assembly without headband

Caution!!! Lamp area will be hot after use.

Loosen the adjustment knob and slide the BIO all the way up. Remove the lamp from its well. Replace with new Welch Allyn lamp. Clean new lamp with alcohol. Insert lamp pin with slot (pin down). Slide lamp cover over lamp. Verify operation of the new lamp.

1.2

Housing Assembly

Unscrew and remove bracket knob. Support the with washer. Remove Remove lamp as per Step 1.1 above. Rremove left and right outer insulators and left/right inner ear insulators respectively . Remove top two screws. Pull back cover off. Remove cable connector assembly . Loosen bottom two screws. Pry off and discard -+- button. Remove two outer bottom screws. Loosen two central screws 3 turns. Do not remove them. This helps VS housing removal. Remove the VS housing form the

BIS

and remove bracket screw, bracket spacer

BIS

from headband.

VS/IS

assemblies.

1.3 Illumination System Place BIO in fixture T-12198 to ease further

(IS)

Sub-Assembly disassembly .

Remove the two central screws that were loosened in the previous step. Seperate the illumination system sub-assembly from the visual assembly .

1.4

1.5 Illumination Lenses When the two hex cap screws are removed from the

Y oke Remove hair spring with tweezers.

Mirror Remove IM yoke and IM mirror/mirror holder sub-

assembly for illumination system bracket.

illumination sub-assembly , it will come apart. Hold the illumination sub-assembly on a foam mat in a horizontal position for complete disassembly . Remove two hex cap screws from heat sink lamp holder. Use 3/32 hex key . Pull Illumination system bracket away from optics carrier. Remove compression spring and mirror tilt control. Remove aperture spacer assembly which contains aperture and filter holders. Remove heat sink lamp holder from contact holder. Remove spring washer, wide band hot mirror disc lens, lens spacer and lens.

1.6 VS Assembly Remove and discard rubber eye cups.

Remove and clean both eyepiece lenses.

End of Disassembly

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