On Monday 06 April 2009 06:36 am, droo wrote:
> I meant their website. Their stores are awful. I still don't understand
> how they stay in business. They sell mostly junk.
Surprisingly, Radio Shack turns out to have something useful afterall. I work
next to a RS store, so I walked over there over lunch yesterday, just to see
if they had anything other than batteries and cel phones.
They do have some 12V bulbs. Most were obviously not going to work (screw
base, or too big, etc.). But I did find two that looked like likely
candidates: a grain of wheat bulb with wire leads, and a "bi-pin base" bulb.
I also stopped at the local NAPA on the way home and got some #74 bulbs.
Last night, I pulled the switch out of the dash and fixed it. Here are the
results of testing the bulb options.
http://www.zaccaria-pinball.com/temp/TCCS-74.jpg
This shows a #74 bulb in relation to the one I'm trying to replace. The #74 is
bigger, plus it's a "wedge base" bulb and there's no socket for it on the
board. I was thinking of modifying the board to fit a socket, or just making
a replacement board and designing in some #74 sized sockets, though I'm not
sure that they'd have clearance on the back to fit in to the switch housing.
You can see, though, that the #74 is somewhat bigger than the dead bulb on the
board. I was worried about it fitting in to the front of the housing, with
the light pipes to illuminate the wording on the front.
http://www.zaccaria-pinball.com/temp/TCCS-GOW.jpg
So I moved on to the Radio Shack "grain of wheat" bulb. This has wire leads
attached, but those could be removed. The bulb looks like it might fit,
though it's still not quite the right physical size. This looked like a
better option than trying to fit the #74 in there, though.
http://www.zaccaria-pinball.com/temp/TCCS-272-1154-bulb.jpg
Now we're looking good. This is the Radio Shack part number 272-1154 "bi-pin
base" 12V bulb. The globe is smaller than the original bulb, but the overall
size is pretty close.
http://www.zaccaria-pinball.com/temp/TCCS-bulbs.jpg
Here are the original bulb (left), 272-1154 (middle), and bulb condom (right).
http://www.zaccaria-pinball.com/temp/TCCS-Bulb-Replacement.jpg
Here's the board with the 272-1154 bulb soldered in place. It's a little bit
shorter than the original bulb, and the white insulator around the bottom is
just a little bit smaller diameter than the original bulb, so the lamp condom
wouldn't fit it (too loose). I solved that with a bit of heatshrink tubing to
increase the diameter, and put the condom on over that.
http://www.zaccaria-pinball.com/temp/TCCS-Bulb-Replaced.jpg
Now both light up, where before I only had the blue one in the middle working.
This is full brightness, 12VDC, from my bench power supply. With the dash
dimmer turned down a bit, I measured 9VDC at the connector, so it won't be
quite this bright installed.
http://www.zaccaria-pinball.com/temp/TCCS-Installed.jpg
And here's the result. Now I have 2WD 4HI and 4LO light up on the switch
again, not just the position indicator LEDs.
Was it worth it? I dunno. I already had the dash apart, and had disassembled
the switch for testing, so it was only a little extra work to warm up the
soldering irons and fix this. I don't know that I'd have done it otherwise,
as I can't say that I had even noticed that it wasn't working until I took it
apart.
Another alternative would be to convert to high output white LEDs, but then
I'd have to modify the board to include the current limitting resistors that
would be required. If I notice that this replacement bulb has burnt out
again, maybe I'll try LEDs next.
This archive was generated by hypermail 2b29 : Mon Jun 01 2009 - 00:37:00 EDT
