Cleaning Lamp Sockets

 From: overturf@bigbootay.sw.stratus.com (Dallas Overturf)

Newsgroups: rec.games.pinball

Subject: Re: Cleaning lamp sockets - suggestions wanted.

Date: 19 Aug 92 22:22:46 GMT

Fixing lamp sockets using bayonet style bulbs (#44, and #47 bulbs).

Note:  All of the following assume that your light bulb is new and

not coroded.

Check light bulb for corrosion at the two bayonet

posts (the two thingys that stick out of the bulb).

These two posts are what make the common connection

to the bulb as well as at the center of the bulb.

There are two problems with the bayonet sockets (not counting bad design)

A.  The bad common connection:

This is the connection from the "screw in tab" to the

base of the socket.  It is a press fit like connection

and when it becomes loose and or corroded, the lamp 

will flicker, dim and or just not work.  To prove it is simple;

touch a wire from the common wire (often this is a bare wire

running to the screw tab on older games though not

always) to the actuall outside of the socket, being carefull

not to press against the socket.  If lamp is correct

        you have a bad common connection.

Fixes:

1.  Put in a new socket. (same old design problem still exists!)

2.  Fix the design.  This can be done with a 100 Watt

soldering gun by soldering the base of the 

socket to the point where it is pressed to

the screw tab.  Be carefull not to bridge the

solder to the center terminal!

Also clean off the two notches in the socket where

the bayonet tabs of the bulb sit.

A small dremmel tool wire brush on the end of a drill

can be used to easily clean the outside base of the socket

where it is pressed against the common screwtab.

B.  Bad center connection: (connection to the center post of the

bulb is bad).  

Proof:  jumper from the center tab to directly to the

center post of the socket, if lamp works then the following

fixes are in effect:

1.  Put in a new socket.

2.  Fix the design as follows:

The design fix here is easy; with a bulb in the socket,

and using a 100 Watt soldering Gun; remove the wire from

the center tab and solder it directly onto the center pin

of the socket.  (you may wish to clean off the center pin

before soldering to it; a file works nicely.)  Be carfull

not to bridge to the socket base connection.

The above assumes that the inside of the socket is clean.

If it is not, then a small "dremmel tool" wire brush on the

end of a drill can be used to easily clean out the inside

of the socket.  This wire brush is tiny and should be available

at most hobby stores.

Warning:  The fixes can be time consuming and require that you

be skillfull with a soldering iron.  If you are not

good with a soldering Iron then do yourself a favor

and replace the socket, or get someone to do the

work who is (Or practice on a spare socket first).

The fix to the bad "common  connection" is time

consuming and while simple it is not so easily done.