stan
May 23rd 08, 07:35 AM
I was fortunate enough to pick-up a Pioneer SX-3700 on eBay recently without
any burned-out bulbs - which is pretty amazing considering the unit was 28
years old and has no less than 11 bulbs inside! Imagine my dismay when,
after using DeoxIT to clean the noisy switches and pots, then reassembled
the unit only to find I had somehow broken two of the bulb filaments while
working on the receiver.
The required bulbs with leads can be purchased through eBay, but not wanting
to wait for the auction to end, in addition to the shipping delay, I thought
I would take a chance with a wired bulb that is readily available from a
nearby Radio Shack. The service manual calls for an 8V; 50 mA bulb, whereas
the closest Radio Shack equivalent is 6V; 25 mA (cat no. 272-1140). Since
the bulbs were only $1.49 each, I wouldn't be out too much money if they
didn't work, either. I snipped-off the old bulbs near the base of the bulb
with wire cutters, then soldered the new wired bulbs with a Ό-Watt; 100-Ohm
resistor in series, to drop the higher supply voltage to match the
requirements of each replacement bulb. You'll need to thread the leads of
the new bulb through the plastic holder before soldering, since the bulb is
too "fat" to be slid up through the back end of the plastic lamp holder. I
wrapped the soldered leads individually with electrical tape, including the
entire resistor and all conductive surfaces to avoid any potential arcing
with other nearby circuitry - ideally heat-shrinking insulation would
probably be a better choice if you have it available.
Also note that the bulb diameter is just a hair larger than the
factory-installed bulb - this shouldn't be a problem, though. The bulb
holder spreads-out from the back-end to the front-end, so the bulb will seat
a bit farther forward - but not so much that it would protrude beyond the
face of the holder. In my opinion this is an advantage, since it increases
the visible luminescence of the replacement bulb - while it consumes half
the current of the bulb it replaces, the brightness seems comparable to its
surrounding siblings.
So if you have a Pioneer SX-3500/3600/3700/3800/3900 with burned-out bulbs,
and you also have a soldering iron, with a bit of care and patience you too
can fix them today!
any burned-out bulbs - which is pretty amazing considering the unit was 28
years old and has no less than 11 bulbs inside! Imagine my dismay when,
after using DeoxIT to clean the noisy switches and pots, then reassembled
the unit only to find I had somehow broken two of the bulb filaments while
working on the receiver.
The required bulbs with leads can be purchased through eBay, but not wanting
to wait for the auction to end, in addition to the shipping delay, I thought
I would take a chance with a wired bulb that is readily available from a
nearby Radio Shack. The service manual calls for an 8V; 50 mA bulb, whereas
the closest Radio Shack equivalent is 6V; 25 mA (cat no. 272-1140). Since
the bulbs were only $1.49 each, I wouldn't be out too much money if they
didn't work, either. I snipped-off the old bulbs near the base of the bulb
with wire cutters, then soldered the new wired bulbs with a Ό-Watt; 100-Ohm
resistor in series, to drop the higher supply voltage to match the
requirements of each replacement bulb. You'll need to thread the leads of
the new bulb through the plastic holder before soldering, since the bulb is
too "fat" to be slid up through the back end of the plastic lamp holder. I
wrapped the soldered leads individually with electrical tape, including the
entire resistor and all conductive surfaces to avoid any potential arcing
with other nearby circuitry - ideally heat-shrinking insulation would
probably be a better choice if you have it available.
Also note that the bulb diameter is just a hair larger than the
factory-installed bulb - this shouldn't be a problem, though. The bulb
holder spreads-out from the back-end to the front-end, so the bulb will seat
a bit farther forward - but not so much that it would protrude beyond the
face of the holder. In my opinion this is an advantage, since it increases
the visible luminescence of the replacement bulb - while it consumes half
the current of the bulb it replaces, the brightness seems comparable to its
surrounding siblings.
So if you have a Pioneer SX-3500/3600/3700/3800/3900 with burned-out bulbs,
and you also have a soldering iron, with a bit of care and patience you too
can fix them today!