Simpson 2 Series - Maintenance; How to Open the Case; Battery Replacement

SECTION III
MAINTENANCE
HOW TO OPEN THE CASE
The case of the Simpson Volt-Ohm-Milliammeter Model 270
Series 2 has been designed to provide easy and quick ac-
cess to the inside for all necessary adjustment and replace-
ment of parts. Use a 1/Á-inch screwdriver to remove the four
screws through the bottom of the case. Then slip the entire
front panel forward out of the case. The meter, the front
panel, the printed circuit, and the batteries are all attached
together and will come out as a unit.
BATTERY REPLACEMENT
There are five batteries inside the case of the Model 270
Series 2. They are used to supply power for resistance
measurements. One is a large size (#2, Size D) flashlight
cell, and the other four are smaller (#Z) flashlight cells.
When it is no longer possible to bring the pointer to O for
the R x 1 and R x 100 ranges (see ZERO OHMS ADJUST,
page 22), replace the large cell with a fresh one. When it
is no longer possible to bring the pointer to 0 on the R x
10,000 range, replace the four smaller cells with fresh
ones. This will restore operation of the ohmmeter circuit.
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