Magnavox L01-1UAC kills HOT quickly
 

Hi. Got a Magnavox L01-1UAC-7638. Came in, shorted HOT. Ordered Mat Elec kit
(HOT, 2 elec caps and 2 driver transistors), put in, lasted 2 weeks. Put
another kit in 3 days ago (thinking maybe a bum part) and HOT died in
minutes. Nothing seemed overly hot, just dropped in chirp from power supply.
No oddball solder joints or anything else obvious. Runs perfectly with great
picture and sound, then dies with no warning.

Flyback perhaps?

Cheers, Danny

Magnavox L01-1UAC kills HOT quickly
 

wrote in message
...
Hi. Got a Magnavox L01-1UAC-7638. Came in, shorted HOT. Ordered Mat Elec
kit
(HOT, 2 elec caps and 2 driver transistors), put in, lasted 2 weeks. Put
another kit in 3 days ago (thinking maybe a bum part) and HOT died in
minutes. Nothing seemed overly hot, just dropped in chirp from power
supply.
No oddball solder joints or anything else obvious. Runs perfectly with
great
picture and sound, then dies with no warning.

Flyback perhaps?

Cheers, Danny



We've seen counterfeit transistors in some of these kits. Often the original
part is the only way to go.
Assuming there's no bad solder connections at the horizontal drive
transformer, you're probably looking at timing caps, (usually blue in color,
I'm told) or B+ too high.

I doubt it's the flyback.


Mark Z.

Magnavox L01-1UAC kills HOT quickly
 

Sounds like a problem in the H drive circuit. There is a mod kit for the
L04 chassis that replaces the H drive coil, a surface mount transistor in
the drive circuit and a resistor. There is some confusion as to whether the
same applies to the L01 that a Philips ASC may be able to clear up. The
parts in the two circuits are different, but the problem may be similar. I
have had several of the L01 sets that had bad H drive transistors and a bad
related cap. The area around the parts was darkened from heat so it is easy
to find.

Leonard

wrote in message
...
Hi. Got a Magnavox L01-1UAC-7638. Came in, shorted HOT. Ordered Mat Elec
kit
(HOT, 2 elec caps and 2 driver transistors), put in, lasted 2 weeks. Put
another kit in 3 days ago (thinking maybe a bum part) and HOT died in
minutes. Nothing seemed overly hot, just dropped in chirp from power
supply.
No oddball solder joints or anything else obvious. Runs perfectly with
great
picture and sound, then dies with no warning.

Flyback perhaps?

Cheers, Danny

Magnavox L01-1UAC kills HOT quickly
 

It is a 32 inch set. I don't have the location numbers at hand, set is at
ladies home and my notes are at the shop, but it came with HOT, 2 small
transistores for H drive, 1 pnp and 1 npn, and 2 caps. I believe they were a
220 and a 47 uf, but don't hold me to that right now.

Danny

Magnavox L01-1UAC kills HOT quickly
 

Alot of forums suggest replacing the transformer 7460, along with
47uF35v cap. to fix this problem. There is a "repair" kit p/n
483531057577 from Andrew's Electronics that contains T8 fuse, diode,
Bu4508DX. I am just a novice electronics tech here, does anyone know
if this would fix the problem?
tvguy wrote:

The known bad crts are A80QCF340X34(N). See what happens when you
remove the anode and the crt board from the crt. See if the hot blows
or not.

Magnavox L01-1UAC kills HOT quickly
 

I haven`t seen anything about the transformer on this problem but
could be. Are those fuse and diode thats listed still good in this
set ? Also do you have the schematic for it. If you need it let me
know with an email addy that I can send it to.

Magnavox L01-1UAC kills HOT quickly
 

In most cases, replacing the transformer won't do anything for you,
since the culprit is usually the failed 47uF coupling capacitor.
That and the circuit designers who decided to use this capacitor to
pass a signal that is hard on electrolytics. When the cap goes
soft, the HOT receives insufficient drive and spends too much time
in linear conduction which generates excess heat. Usually the cap
and transistor are all that need replacing. The "kit" is a shotgun
approach that contains extra parts you may need only rarely. And
some people calling themselves "techs" do not seem to have the
diagnostic skills to figure out what is really wrong, so kits work
well for their "bag of tricks" approach to repair.

In article . com,
says...
Alot of forums suggest replacing the transformer 7460, along with
47uF35v cap. to fix this problem. There is a "repair" kit p/n
483531057577 from Andrew's Electronics that contains T8 fuse, diode,
Bu4508DX. I am just a novice electronics tech here, does anyone know
if this would fix the problem?

Magnavox L01-1UAC kills HOT quickly
 

The kit from Philips for the L04 chassis contains the transformer, drive
transistor, and a resistor. That chassis will eat the output and I suggest
installing the Philips kit. Every one of the L01 sets that I have seen has
had a bad cap and drive transistor, but none has caused a failure of the
output transistor.

Do any of you Philips ASCs know if there is a kit from Philips for the L01?

Also, please post at least something from the previous post, if not more of
the thread, so that we can know to whom you are responding and add some
context to your post.

Leonard

"tvguy" wrote in message
...
I haven`t seen anything about the transformer on this problem but
could be. Are those fuse and diode thats listed still good in this
set ? Also do you have the schematic for it. If you need it let me
know with an email addy that I can send it to.

Magnavox L01-1UAC kills HOT quickly
 

"Leonard Caillouet" wrote in message
news:wSXNf.77234$bF.29338@dukeread07...

Do any of you Philips ASCs know if there is a kit from
Philips for the L01?

MAT Electronics in their 2006 winter catalog lists
the LO1.1U repair Kit #: 62-280, for US$ 4.95
or 10 for US$ 4.50 each. Includes 1 each:
BU4058DX, BC547, BC557, 47M/50V, 220/35V
It is a good deal! For more info:

www.matelectronics.com Fax: 1-800-628-1005