I got a Malibu 600 watt transformer. Model ML600TW. When I rotate the
on/off knob, it makes the sound of smacking the outer housing with a stick.
A loud audible clank. Then it hums.

When I apply the tester to the bottom connectors, I can't get it to read
anything. Double checked tester with various voltage alkaline batteries on
DC, and they tested fine, so tester is good.

Is this transformer fried? Is the humming normal? Is that clanking noise
normal?

Steve

Steve B wrote:
I got a Malibu 600 watt transformer. Model ML600TW. When I rotate the
on/off knob, it makes the sound of smacking the outer housing with a stick.
A loud audible clank. Then it hums.

When I apply the tester to the bottom connectors, I can't get it to read
anything. Double checked tester with various voltage alkaline batteries on
DC, and they tested fine, so tester is good.

Is this transformer fried? Is the humming normal? Is that clanking noise
normal?

Steve

Mine did just about the same thing.
Upon opening, it was built very cheap. I
tightened the transformer laminations
the best I could, however, they were not
designed to be tightened. I dribbled
some shellac into the laminations and it
made
the hum tolerable. I think I also beat
on it with a hammer to tighten it as much
as possible. I've heard of people
dribbling glue, etc. to try to solve
transformer
humming.

"Art Todesco" wrote in message
et...
Steve B wrote:
I got a Malibu 600 watt transformer. Model ML600TW. When I rotate the
on/off knob, it makes the sound of smacking the outer housing with a
stick. A loud audible clank. Then it hums.

When I apply the tester to the bottom connectors, I can't get it to read
anything. Double checked tester with various voltage alkaline batteries
on DC, and they tested fine, so tester is good.

Is this transformer fried? Is the humming normal? Is that clanking
noise normal?

Steve

Mine did just about the same thing. Upon opening, it was built very cheap.
I
tightened the transformer laminations the best I could, however, they were
not
designed to be tightened. I dribbled some shellac into the laminations
and it made
the hum tolerable. I think I also beat on it with a hammer to tighten it
as much
as possible. I've heard of people dribbling glue, etc. to try to solve
transformer
humming.

Geez, now I'm really scratching the twins. Upon testing with a tester, I
don't get anything. When I hook up a test wire and run it to a spare lamp,
the lamp lights. Apparently, the transformer is still good. I can see no
user serviceable fuses or resets. I'm going to pull the cover and look
inside, but at least I don't have to go buy another one.

Steve

wrote

what kind of "tester"? Is it for AC? Something looking for DC will
probably not see anything on AC

Good Craftsman AC/DC multitester.

Steve

"Steve B" wrote in message
...

wrote

what kind of "tester"? Is it for AC? Something looking for DC will
probably not see anything on AC

Good Craftsman AC/DC multitester.

Test it on an ac outlet. Might not be working.

Steve B wrote:

Geez, now I'm really scratching the twins. Upon testing with a
tester, I don't get anything. When I hook up a test wire and run it
to a spare lamp, the lamp lights. Apparently, the transformer is
still good. I can see no user serviceable fuses or resets. I'm
going to pull the cover and look inside, but at least I don't have to
go buy another one.

Probably needs a load to do its thing.

On Mar 15, 3:36 pm, "Steve B" wrote:
"Art Todesco" wrote in message

et...





Steve B wrote:
I got a Malibu 600 watt transformer. Model ML600TW. When I rotate the
on/off knob, it makes the sound of smacking the outer housing with a
stick. A loud audible clank. Then it hums.

When I apply the tester to the bottom connectors, I can't get it to read
anything. Double checked tester with various voltage alkaline batteries
on DC, and they tested fine, so tester is good.

Is this transformer fried? Is the humming normal? Is that clanking
noise normal?

Steve

Mine did just about the same thing. Upon opening, it was built very cheap.
I
tightened the transformer laminations the best I could, however, they were
not
designed to be tightened. I dribbled some shellac into the laminations
and it made
the hum tolerable. I think I also beat on it with a hammer to tighten it
as much
as possible. I've heard of people dribbling glue, etc. to try to solve
transformer
humming.

Geez, now I'm really scratching the twins. Upon testing with a tester, I
don't get anything. When I hook up a test wire and run it to a spare lamp,
the lamp lights. Apparently, the transformer is still good. I can see no
user serviceable fuses or resets. I'm going to pull the cover and look
inside, but at least I don't have to go buy another one.

Steve- Hide quoted text -

- Show quoted text -

All that you are hearing is the timer contacts closing and the
transformer kicking in. I have had the same model as you for 4 or 5
years, what you are experiencing is normal. The transformer hum
usually lessens once it settles in and is barely noticable after that,
but yeah, when it kicks in one can hear it some distance away.

On 15 Mar 2007 14:21:50 -0700, "volts500" wrote:


- Show quoted text -

All that you are hearing is the timer contacts closing and the
transformer kicking in. I have had the same model as you for 4 or 5
years, what you are experiencing is normal. The transformer hum
usually lessens once it settles in and is barely noticable after that,

You may be thinking of basketball.

but yeah, when it kicks in one can hear it some distance away.

On Thu, 15 Mar 2007 11:39:32 -0700, "Steve B"
wrote:

I got a Malibu 600 watt transformer. Model ML600TW. When I rotate the
on/off knob, it makes the sound of smacking the outer housing with a stick.
A loud audible clank. Then it hums.

When I apply the tester to the bottom connectors, I can't get it to read
anything. Double checked tester with various voltage alkaline batteries on
DC, and they tested fine, so tester is good.

But if this thing is a transformer, isn't its output supposed to be
AC. That the tester will test DC doesnt' mean it is ok on AC. Each
setting usually has its own resistor, and even the switch contact
could conceivably be broken. Not that I think this has happened,
but..

Is this transformer fried? Is the humming normal? Is that clanking noise
normal?

Steve

On Mar 15, 6:11 pm, mm wrote:

But if this thing is a transformer, isn't its output supposed to be
AC.

Yes, the output of that model transformer is approx. 12 volts AC. As
you said, if he uses the DC scale on his meter it's going to read zero
volts.

"volts500" wrote in message
oups.com...
On Mar 15, 6:11 pm, mm wrote:

But if this thing is a transformer, isn't its output supposed to be
AC.

Yes, the output of that model transformer is approx. 12 volts AC. As
you said, if he uses the DC scale on his meter it's going to read zero
volts.



Bingo. The label says 110 in, 12v out, but doesn't say AC or DC. When I
just put it on the AC scale, it was 12.0 volts. I saw the automotive style
bulbs used on some of the lights, and ass-u-med that it was DC.

You learn something every day.

Steve

Steve B wrote:
I got a Malibu 600 watt transformer. Model ML600TW. When I rotate the
on/off knob, it makes the sound of smacking the outer housing with a stick.
A loud audible clank. Then it hums.

When I apply the tester to the bottom connectors, I can't get it to read
anything. Double checked tester with various voltage alkaline batteries on
DC, and they tested fine, so tester is good.

Is this transformer fried? Is the humming normal? Is that clanking noise
normal?

Steve



This is a switching power supply, which requires a load to show an
output w/ a conventional VOM. A scope is needed to see what's really
going on with these.

Rob

trainfan1 wrote:
Steve B wrote:
I got a Malibu 600 watt transformer. Model ML600TW. When I rotate
the on/off knob, it makes the sound of smacking the outer housing with
a stick. A loud audible clank. Then it hums.

When I apply the tester to the bottom connectors, I can't get it to
read anything. Double checked tester with various voltage alkaline
batteries on DC, and they tested fine, so tester is good.

Is this transformer fried? Is the humming normal? Is that clanking
noise normal?

Steve


This is a switching power supply, which requires a load to show an
output w/ a conventional VOM. A scope is needed to see what's really
going on with these.

Rob
I may be wrong, and frequently are, but
I don't think any Malibu light power
units use a switching power supply.
They usually, as has been stated, run
simply on the AC output of an old
fashioned transformer. But, with that
said, I have seen 12 volt "transformers"
for indoor low voltage lighting, which
do use switching power supplies. So,
anything is possible. The advantage of
the switching power supply is a
reduction in size and weight.

Art Todesco wrote:

trainfan1 wrote:

Steve B wrote:

I got a Malibu 600 watt transformer. Model ML600TW. When I rotate
the on/off knob, it makes the sound of smacking the outer housing
with a stick. A loud audible clank. Then it hums.

When I apply the tester to the bottom connectors, I can't get it to
read anything. Double checked tester with various voltage alkaline
batteries on DC, and they tested fine, so tester is good.

Is this transformer fried? Is the humming normal? Is that clanking
noise normal?

Steve


This is a switching power supply, which requires a load to show an
output w/ a conventional VOM. A scope is needed to see what's really
going on with these.

Rob

I may be wrong, and frequently are, but I don't think any Malibu light
power
units use a switching power supply. They usually, as has been stated, run
simply on the AC output of an old fashioned transformer. But, with that
said, I have seen 12 volt "transformers" for indoor low voltage
lighting, which
do use switching power supplies. So, anything is possible. The
advantage of
the switching power supply is a reduction in size and weight.

That 600 watt transformer, at 12 volts output(600 VA or 45-55 amps),
would be 50+ lbs. if it were NOT a switching power supply.

Rob