Question about SAMTRON 55V 15" CRT Monitor

# Set dead no smps starts but 300v dc supply is ok and ground to filter capacitor positive termial 145 v is ok but no dc volts in out put

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• ronnel Mar 03, 2008

my samsung samtron 553 is when you turn it ON,the LED will light then it will sond shsssssss then it will turn of

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All the dc voltage out from sm but monitor not on

Posted on Feb 12, 2008

All the dc voltage out from sm but monitor not on

Posted on Feb 12, 2008

• Level 1:

An expert who has achieved level 1.

• Contributor

Try replacing the filter capacitor of the PWM ic. 47uF-50v.

Posted on Feb 07, 2008

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
goodluck!

Posted on Jan 02, 2017

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## Related Questions:

Tip

### How to wire and size a potential relay

To size a potential relay you must read the Start winding voltage (the BEMF)
which will be above the supplied line voltage, in this example I use 300 volts for math.
BEMF = 300 volts,
300v x ,50 = 150v minimum
300v x .80 = 240v maximum
300v x 1.20 = 360v continuous
So you want the Start capacitor to stay in the circuit to at least 150v BEMF or risk stalling, and you do not want the Star capacitor to stay in beyond 240v BEMF or risk
exploding the Start capacitor.
The 120% continuous rating is to oversize the coil in the potential relay that remains in the system to protect it .
If you have a compressor that is not running you will need to jump it with a Start capacitor(a large one) to the run capacitor for 1 second or so to bump start the compressor, then you can read the Start winding for the BEMF reading.

on Oct 14, 2013 | APPROVED VENDOR Potential Relay, 35A, Pick...

### Have Eiki LC-X1000 projector. Recently had a power outage and since then it has not come back on. Have tried the reset, 230 AC ok and 300 DC volt ok, No standby light, nothing,then what can i do

dried out smd capacitors in primary part of power supply , common problem with this and similar models. 1uf, 2.2 uF and 1 radial 220 uF
replace bij 105 oC type

Apr 05, 2012 | Eiki LC-XG250 LCD Projector

### I have a desktop PC that when I turn it on it will power up and then after 6 seconds turn back off.

The first solution is right on the money, It's the video card, or many of us today forget to plug the damm thing in and the computer doesn't read and we think that there is a serious problem. If none of this helps then try troubleshooting through this PC repair guide. Hope this helps.

Dec 29, 2011 | E-Machines eMachines Desktop PC

### I have a EMACHINE W5243 with a MCP61SM-GM Motherboard. When I press the power button the keyboard lites flash, fans come up to full speed than drop to a slower speed, than I get beeps about every...

Suggest Don, that you check the voltage power rails in the Power Supply, first. Make sure the Power Supply is working correctly.

Power Supply voltages check out, look VERY close at the motherboard.
(Power unplugged to computer, Anti-Static Precautions taken, motherboard OUT in hand )

Reasoning?

eMachines are budget computers. Nothing wrong with that. Problem is the manufacturer saved the consumer on the cost, by using two low quality components.

A) The Power Supply
B) The motherboard

Both of these come up for the BIOS Beep Code you stated.

Power Supply's are usually Bestec, Delta, or HiPro.
These particular generic units use low quality Electrolytic Capacitors, MOSFET's, Rectifier Bridge, less than adequate gauge of wiring, and so on.

The motherboards, (MSI, ECS, TriGem, etc), use low quality Electrolytic Capacitors.
This is generally the item/s that go bad first. They are the 'weakest link'.

Yes, Electrolytic Capacitors are the weakest link in the Power Supply, also.

In the Power Supply they are used as Filters. They filter the incoming AC electricity, (Input Stage), and the outgoing DC electricity. (Output Stage)

http://en.wikipedia.org/wiki/Switched-mode_power_supply

I really feel the problem is the Power Supply.
Why?
1) If ALL of the LED lights were on at once, they would use less than 1 Watt of power.

2) EACH fan uses 2 to 3 Watts of power.

3) A typical Processor can use 51 to 125 Watts of power. Just depends on what Processor it is. (Older Intel Pentium III's, II's, and so on, use less power than 51 Watts. Same with older AMD processors )

(The PSU { Power Supply Unit} in your personal computer is a SMPS.
Switched-Mode Power Supply)

Click on the photo to the upper right, in the link above. The letter B is on the top of an Electrolytic Capacitor. You are looking at a Top View.
The blue ring is part of a plastic sleeve, which goes around the 'can' case of the capacitor.
These large capacitors are in the Input Stage.

The letter E is near a few more Electrolytic Capacitors. These capacitors are in the Output Stage.
These capacitors are Radial Aluminum Electrolytic Capacitors.
This is a side view of an example,

http://en.wikipedia.org/wiki/File:Capacitors_electrolytic.jpg

The top capacitor is an Axial Electrolytic Capacitor. The leads come out of each end. The bottom capacitor is a Radial Electrolytic Capacitor. Both leads come out of the same end. The capacitors in your Power Supply, and on your motherboard, are Radial Aluminum Electrolytic Capacitors.

Your Power Supply converts AC electricity form your home, or business, and turns it into low DC electricity.

A) The 3.3 Volt power rail
B) The 5 Volt power rail
C) The 12 Volt power rail.
(In comparison two D cell flashlight batteries produce 3 Volts DC )

In the power cables coming from the Power Supply.
1) Orange wires are 3.3 Volts
2) Red wires are 5 Volts
3) Yellow wires are 12 Volts
(All DC voltage)
Black wires are Ground wires.

Now, about the voltage power rail.
All 3.3 volt wires (Orange), end in one central 3.3 Volt point, in the Power Supply.
The central point is the 3.3 Volt power rail.

Same for the 5 Volt power rail. All 5 Volt wires (Red), end in one central 5 Volt point, in the Power Supply.
Same for the 12 Volt power rail.

This means, for example, if you test one Orange wire, and it shows 3.3 Volts on the multimeter, the 3.3 Volt power rail is good.
Test one Red wire in a power cable. Shows 5 Volts, or VERY near?
The 5 Volt power rail is good.
Same thing for the 12 Volt power rail.

One method to check the 5 Volt power rail, and the 12 Volt power rail.
Use a 4-pin standard Peripheral power cable. (The connector on the cable is misnomered as a 'Molex' connector),

http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral

Most of the time there is an unused Peripheral power cable.
You can use it's Red wire, Yellow wire, and Black wire, to test for 5 Volts, and 12 Volts.

Disregard the following if you are aware;
An economical multimeter can be purchased for around \$5 to \$12.
Available in a multitude of stores. An auto parts store is but one example.
Analog, or Digital, is fine.

The Red lead is the Positive lead. The metal tip is the probe. I refer to both as the Positive probe lead.

The Positive probe lead ALWAYS goes to the power wire to be tested.
3.3 Volt, or 5 Volt, or 12 Volt.
The Negative lead ALWAYS goes to Ground. (A-N-Y Black wire, is a Ground wire)

Computer sitting on a table, or workbench, computer case open, 4-pin standard Peripheral power cable, untangled, and pulled to the outside where you can access it easily, the computer is plugged into power.

The center knob in the middle of the multimeter, is the Function Knob.
It is set to DC Voltage.
If there are only symbols, the symbol is a dotted line over a solid line.
(NOT a curved line over a solid line)

If there is more than one setting for DC Voltage, set it to the 0 to 50 Volt scale.

Turn the computer on. Holding the connector in your hand, of the 4-pin Peripheral power cable, insert the Positive probe lead's tip, into the socket hole with the Red wire.

Hold the probe lead, with the hand that is already holding the connector. With the other hand, insert the Negative probe lead's tip, into the socket hole with one of the two Black wires.

Watch the multimeter. You should be reading close to 5 Volts.
Test the 12 Volt wire using this method also. (Yellow wire, and Black wire. Black wire is Ground. Either one of them)

The 3.3 Volt power rail is tested using the Orange wire, in the 24-pin ATX main power cable.

http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24

Power cable plugged into the motherboard, as in the photo to the right.
At the end of every wire, going into that long whitish connector with 24 socket holes, is a metal terminal.

The metal terminal is pretty far down in the socket hole. The probe lead must touch the metal terminal, but cannot due to it's size.
Use a straightened out paper clip.

The paper clip's diameter is small enough to slide into the socket hole, RIGHT NEXT TO the Orange wire, and touch the metal terminal.
Then the Positive probe lead is held against it. (Or with an alligator clip attachment, it is clipped on)

Do the same for A-N-Y of the Black wires. They are all Ground wires. Pick one. Insert a straightened out paper clip. The Negative probe lead touches it.
(Paper clips inserted, THEN computer turned on. It is only 3.3 Volts DC, but I want you to feel safe)

More in a Comment.

Dec 13, 2011 | E-Machines eMachines Desktop PC

### When my computer starts the power light will blink and the fan starts. When the computer first had problems it froze and the fan turned on and wouldnt stop. I also smelt a burnt rubber smell. I read to...

Yes the voltmeter measures the voltage.
When you power up the computer to test the voltage on the 4 wire connectors.
Test the voltage red and balck wire should read 5 volts.
Test the voltage yellow an black wire should read 12 volts
If the burning smell is from the power supply then most likely a capacitor has blown in the switch mode power supply.
I would advise you purchase a new power supply, do not try and repair it, these mains devices can be dangerous if you don't have knowledge.

Sep 14, 2010 | HP Pavilion a705w PC Desktop

### I BOUGHT MY BROTHERS COMPAQ PRESARIO PC OVER A YEAR AGO AND THE GREEN LIGHT HAS GONE OUT AND I CANT GET IT TO TURN ON,BUT THE MONITOR STILL WORKS. I WOULD LIKE TO TRY AND FIX THIS ON MY OWN,OR WOULD IT BE...

I also think it has something to do with the SMPS.

MOST computer failure can be attributed to Power Supply failure.
MOST computers out there are dirty inside, as well as the Power Supply.

Also, your diagnosis of the green light going out indicates PSU failure.
(Power Supply Unit)

The two cooling components for an SMPS are it's Fan, and any Heatsink's used inside.

Heatsink:
Generally a metal plate that has tall, thin fins protruding from it.

The metal plate absorbs heat from whatever object it is placed against, and the fins absorb heat from the metal plate.

The fins then radiate the heat away.
If a cooling fan is used in conjunction with the Heatsink, the air movement helps to dissipate the heat, that has been absorbed by the fins.

Internal view of an average SMPS,

http://en.wikipedia.org/wiki/Switched-mode_power_supply

Upper right photo. (You can enlarge the photo by Left-clicking on it. You can enlarge it twice)

Once the cooling components of the SMPS are clogged with 'Gunk', the cooling capacity drops tremendously.

Heat = Wasted Energy

The SMPS tries to keep up with the call for power, but eventually cannot, and hardware components inside the SMPS fail.

NEVER open a SMPS, and try to repair it, unless you are a qualified tech. A qualified tech, knows the proper procedure to drain the power from the capacitors, before working on the unit.

(Frankly it's not worth the effort. The procedure is to just replace the SMPS)

Inside the SMPS are Electrolytic Capacitors.
They are used as Filters.
They filter the incoming AC electricity, (Input Stage), and the outgoing DC electricity made by the SMPS. (Output Stage)

An Electrolytic Capacitor slowly builds up a charge, and then releases it all at once.

You may compare it to a large swimming pool being filled up by a garden hose, then one wall of the pool is taken down all at once.

Electrolytic Capacitors hold a charge for Weeks, Months, or even over a year, in some instances, after being removed from power.

(In this instance it would be unplugging the PSU from power)

IF, your finger/s touch the terminals on the bottom of a Radial Aluminum Electrolytic Capacitor, the charge could be released to You!

IF, your fingers complete a circuit, that one or more of those capacitors are in, the charge could be released to You!

Shock can be Bad to Fatal!

(See those two large Electrolytic Capacitors, in the SMPS link photo I provided?
Upper left corner of the SMPS photo. They have blue plastic sleeves around them. They are indicated by the letter B.

These are Electrolytic Capacitors used in the Input Stage. If they are good, they have enough power stored to put X's in your eyes)

Ready to test this puppy (SMPS), or replace it? Just post in a Comment. (Believe upper right of your page)

(The SMPS in your computer puts out three main Voltages.
A) 3.3 Volts (DC)
B) 5 Volts (DC)
C) 12 Volts (DC)

Two C cell flashlight batteries produce 3 Volts (DC)

The test is done with a multimeter, or a power supply tester.
One example of a power supply tester,

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5250576&CatId=5471 )

Buy a new Harddrive for it? Why?
If you do, be prepared to buy another genuine copy of Windows.

Information on the Compaq Presario SR1530F desktop computer;

HP Support>Compaq SR5301F desktop computer>Product Specifications main menu,

Jun 09, 2010 | Compaq Presario 5000 PC Desktop

### Where to hook up com neg. lead to check dc volts on tv????

Most TVs today use a "hot-chassis" design and a switch-mode power supply. You should use an isolation transformer when doing any service work on a TV. This helps protect you and your test equipment, and can prevent accidental damage to the TV by grounding parts to the wrong point.

Hot-chassis sets use two different grounds. The power supplies have one ground reference for the primary side (hot ground) and a different point for the secondary (cold ground). The point you pick will depend on what part of the TV you're measuring.

If you are troubleshooting a dead set and working on the primary side of the power supply, use the negative lead of the large electrolytic capacitor you'll find near the AC input connection. There's almost always a bridge rectifier and filter cap (300 to 400 uF range, 180 to 250 volt rating, so physically pretty large) in that area to make the raw DC. That's a guaranteed good hot ground. Sometimes the set will have a labeled hot ground point right on the circuit board for you.

For measurements on the secondary (output) side of the supply, almost any shield can is ground. The tuner cover is a good choice.

Jan 29, 2009 | Sanyo DS25390 TV

first remove all the dust from smps then check power cord output by multimeter whether right or not ok then open and you will find one fuse there check it without supply if open then replace it if not then check whether a.c. supply reaches or not if present then check the thermister resistance it should be low also check the dry solder if present then remove it please check dc supply at primary filter (big cylendrical capacitor) if not present then 4 bridge rectifier diodes may faulty replace it

Oct 23, 2008 | Mad Dog Multimedia SurePower (MD-350WPS)...

There should be a small valued cap in the primary side (22ufd?) at 250V. Check that. Also, look for other small caps int he range of 2.2ufd with 200V ratings in the same general area.
Dan

May 07, 2008 | Televison & Video

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