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Cannot find datasheet or replacement part - flyback transformer

Jman89

Nov 24, 2015
1
Joined
Nov 24, 2015
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1
Hello,

So I have an old LCD monitor that I put aside because of a high pitch squeel. I now have a use for it and am trying to fix it, I have narrowed the noise down to a flyback transformer which is part of the SMPS but I cannot for the life of me find a datasheet for it or find a replacement part with the same dimensions/winding setup.

The information labeled on it is as follows:

DELTA
2804004600
E115982 MP-130I
DCGM 0723A

Any help or advice would be appreciated, also see attached image of the item.
 

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dorke

Jun 20, 2015
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Try searching by the monitor brand and model.
If you can find it's service manual,it may lead you to the part you need.
 

73's de Edd

Aug 21, 2015
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Sir jman89 . . . . . . . ( so that makes you ~26 ?)


Hey feller . . . . .I'll swap you a much BIGGER blurred pic-choor, for your much smaller blurred one.

Seems like Delta ( RED Box logo on the pcb) provides stand alone power supplies for several big name manufacturers.

Your shown unit is different from THIS one, but both of them use that commonly shared MP-301 switch mode power transformer .
Looks like yours dates from a 23rd week of 2007 date of manufacture, while this unit is being a 21st week of 2006 unit.

As far as your mentioned "flyback " transformer being used . . . . . a la . . . being found in older conventional CRT tubed monitors /and / Tee Wee's.

The closest you will get to finding that part on a LCD unit, are the inverter transformers that kick out a couple of KV's for the sets
mini back light CCFL lamps.

You can see 2 being used on this unit, ( RED stars), the bigger the screen size, the need for more CCFL back light lamps and their HV inverters.

Look at this units board part number ( DAC 12M033 xxx ) and pass on the board number that is being on YOURS.

You mention of a "squeal" and somehow, I just am assuming that it is being up in the high 5-10 Khz audio spectral region.
Since the unit is basically operating up in the ~ 150 Khz frequency region, some sub harmonic of the pulse width modulation of that frequency must be exciting
some inductive element and it is then acting as a "transducer" for your ear to then hear..
In addition to the core of that ferrite cored transformer , any surrounding inductors like the mini bobbin 3.3 uh inductors seen at the very top of this picture.
Also you might have some ferrite bead(s) being used at the primary of the power transformer and its power semi, being located in the area at the side of the 150 ufd
400 V main raw DC filter .

Note the liberal use of "white pookie" around the board, in addition to holding parts in position it also DAMPENS any tendencies of a part to become a "transducer".
When SNOOPING, touching a pencils soft rubber eraser to a suspect part can dampen its acoustical output and cast suspicion on that device.

Can I assume that the "noisy" board syndrome, developed gradually with time, and was not there on day ONE, when the unit was fresh out of the box?

At the very top of the board are all of the power transformers secondary FILTER / BYPASSING electrolytic capacitors .
With time onset and the "HAMMERING" of them with the powerful square waves across them, gradual heating onset can warm up their internal elctrolyte and pressure
build up can let a smidgen escape as vapor at the wire lead /plug interface.
This effect is incremental, and with time onset, progressively more of the electrolyte will dissipate and a "drier" electrolytic evolves.
The heating effect also accompanies the effect along with a higher vapor pressure build up and an increasing ESR.
This shows up as a HOTTER case temperature, the taking on of a bulge in the alumin-i-ninny-yum-yum case top / dome.
Eventually the case ruptures at the cross indentions, designed as a weakened area and placed there just for that reason.
That way, a controlled rupture can occur there, instead of a case explosion, and a launching of the case at another random weak area.

This info below may be why your "noise" has developed.

When a leg of a SMPS secondary voltage source starts developing an increased ESR, any series resistance / or / inductor before its filter capacitor will start
heating more in the case of a resistor, or the inductor will both heat and "ring" with that increased current through it, due to the poor bypassing now being provided by
its deteriorated companion electrolytic.
Indeterminate spurious parasitic oscillation onsets maybe another side effect.
You can also catch fault with the determination that a 'lytics case is running hotter or warmer than others, by the placing of a fingertip atop them to temperature
sample.
God forbid . . . . . if you are blessed with an IR/Laser spot thermometer.

The failure mode on this referenced power supply below was mainly the three YELLOW upwardly domed electrolytics and the very top one which had split open and
totallyvented.

Analyzing your problem . . . . . Howtodoittoit . . . . . .

To more closely zero in on the PRECISE source of your high frequency friend xxxxxxxx "fiend", use a stethoscope or if not automechanically or medically gifted, a
length of clear vinyl aquarium tubing inserted in one ear with a tissue paper plug / wrap will make up a selective sound probe, while your finger holds the other ear closed.
In a pinch, a drinking straw will also suffice, if you initially get in close and pre- position and then bring in the ear to the free end.

No extra charge . . . . if you want to get the absolute maximum side effect . . . .check to see if there might be an "audience" present and then break out into one of your
loud vocal transcendental . . . .OOOOOOOOOOOOOOMMM's . . . while WILDLY flailing that one free arm about in the air.

Standing by for your findings or any further comments. . . . . .

Reference technopix . . . . .

awh9xCk.jpg




73's de Edd




.
 
Last edited:

davenn

Moderator
Sep 5, 2009
14,077
Joined
Sep 5, 2009
Messages
14,077
Hello,

So I have an old LCD monitor that I put aside because of a high pitch squeel. I now have a use for it and am trying to fix it, I have narrowed the noise down to a flyback transformer which is part of the SMPS but I cannot for the life of me find a datasheet for it or find a replacement part with the same dimensions/winding setup.

The information labeled on it is as follows:

DELTA
2804004600
E115982 MP-130I
DCGM 0723A

Any help or advice would be appreciated, also see attached image of the item.

Edd has given you lots of good info
Its unlikely to be the transformer, that is VERY rare, even if it is making the noise. It is likely to just be "complaining" due to incorrect voltages etc
caused by the possible failing electrolytic caps and any other problems

So check ALL the electro's replace any that have obviously bulged at the top and consider replacing the others anyway
if they haven't failed yet, they are probably well on their way


Dave
 

amendar

Jul 2, 2013
3
Joined
Jul 2, 2013
Messages
3
Hey 73's de Edd, man I will read all of your post here!

You explanation was wonderful. Thanks.
 
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