Question about Computers & Internet

Open Question

Motherboar short power supply canot working (protect)if i connect to my laptop and the others chipset include onmainboard very hot @regulator sytem

Posted by on


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Connex 3300 went to ground what can i do

There is something shorted in the power supply. See if you can get a schematic from their website. Most likely parts to check are the voltage regulators, protection diodes and capacitors. A shorted diode will go to ground too.

Nov 19, 2014 | Connex 3300 240-channels Mobile Cb Radio...

1 Answer

Kv-27exr10 wont turn on

Have someone open and check in power supply on left side as seen from rear the .1 ohm protect resistor and the two regulators near it, and check for short to ground on horizontal output on other side mounted on metal--read from center pin to ground.

This set starts with a bad connection on t401--horizontal drive transformer and escalates to output transistor, two regulators, protect resistor all being bad= about 25 dollars in parts.

let me know if questions.

May 29, 2012 | Televison & Video

1 Answer

I have a JVC TV AV-21DTG2 the TV goes on protection mode as soon as I switch on the mains power

The power supply regulator section circuit has to be troubleshooted. There might be some shorted component/s. It is a skilled work. You must have sound knoledge in electronics to do this work.

Apr 24, 2012 | JVC AV-32D305 32" TV

1 Answer

Mains supply fuse blows

There is some short circuit with the power switching regulator section. Check the MOV [Metal Oxide Varistor] connected accross the main AC power line, on board. This device will look like a ceramic capacitor, usually green or black in color. If any voltage spike comes over, this device will get shorted, and the fuse will burn off; thus it is used as a protection against overvoltage and current spikes. If it is alright, check the rectifier diodes or stalk rectifer fitted for any reverse short. You can measure the short very easly by measuring the resistance between the two terminals of the main resevoir capacitor. If this point shows any short, check out the revalent components, including the power switchig device, either it is transistor or an STR, whatever may be. Anyway, there is a direct short in your power supply regulation system of your TV. Get it repaired first, before put a new fuse in place. OK.

Aug 14, 2011 | Toshiba 27WL46 27 in. LCD Television

1 Answer

Our lg tv was going ok the night before and when we went to turn it on the next morning it would turn on but not get any sound or pictures and it would not stay on. it was a hot day the before


This is an indication that you have a problem on the power supply section or on the load because of the following reasons : 1. Over Voltage - the regulator might be cycling on over voltage due to lack of load. 2. Over Current Protection - excessive load or faulty power supply cycling will trigger the over current protection circuit. This is because of open fusible resistor in line with a shorted Voltage regulator IC. 3. Leaky Capacitor - a dried up main filter capacitor or other filter capacitor in the power supply that is producing an out-of-regulation condition. A bad filter capacitor on the output of a series regulator may result in excessive/drop of voltage. 4. A problem with the microcontroller, relay or its driver, or standby power supply.

This is not DIY and quite technical, I've advice you to look for a qualified technician or send it to repair shop to isolate the problem.

But first check if your unit is under warranty then avail it because the manufacturer of your unit will fix it for free or with a little charge only.

Hope it may help you.

Have a nice day!

Thanks for using Fixya.

Feb 10, 2011 | LG Televison & Video

1 Answer

What is the first step in troubleshooting color television? dead set..blown fuse..

You haven't specified anything about your Sony Tv. No model number or anything to compare. Although I hereby giving you a general trouble shooting method, first adopted by technicians like me. You have stated that the fude has blown out. Fuse will not burn out without any reason. it is a protective device used in every telivisions,as if any internal components inside it gets shorted, especially in power supply section, the fuse will get burned and protect the other components from further distruction. Therefore you have to trace the reason for the failure of fuse first.
You must beging it from power supply regulator section itself. Chech the resistance accross the main filter capacitor first. Set the multimeter in Ohms range, and the resistance must be above 250Ohms in one direction, and upto infinite in the other direction. If both readings comes below 20Ohms or so, suspect the power regulator Ic; usually sony sets udes STR type regulated power supply, and this STR will get shorted. As you haven't specified your sets model, I can't make sure whether it is circuted with STR or a switching transistor. As both cases, this regulator has a chance to get shorted. Desolder it out and check for short. if it finds shorted, check the rlated components also, such as zener diodes and resistors, for open and short,as they also will get damaged due to this main switching transistor, or STR; whatever may be.
Check the degaussing posistor for short. Check the rectifier stack for short. Check the mains filter capacitor for short. Check each and every diode for short. you must measure the forward reisistance of diodes with multimeter set in 100KOhms range. There shouldn't be any slight leak with this test. If it shows a slight leak, replace it. You just do these and inform me the result through Fixya. I'm ready to assist you furthermore. When you reply to me; please include the model number of your Sony Tv. Ok.

Dec 12, 2010 | Sony Televison & Video

1 Answer

Lambda ews600-18 voltage goes down.

there is a short circuit protection and overoad protection to smps so o/p capacitor may short or secondary diode may short .so check voltage at primary when switched off after 33seconds whether switching process is going or not for that check dc volt at i/p capacitor then check volt at collector of transistor if metr shows 1digit then switching is going if not then meter shows full dc volt check component near about that

Apr 13, 2010 | Lambda 40-Watt Power Supply

1 Answer

TDA3653 keeps blowing when the TV is switch ON

Without checking components associated with the TDA3653, the exact cause is impossible to say.
This IC has extensive built in protection circuitry that should protect it from overloads caused by such things as shorted turns in the vertical deflection coil, or from faults with any associated components, e.g. open/shorted resistors/diodes/capacitors.
The following data sheet describes this IC in detail:

Therefore as the IC keeps failing at switch on, and if no other components are failing or suffering damage, suspicion must fall on the supply voltage delivered to Pin 9 and Pin 6 being excessively high (or spiked) and thus causing a rapid demise of the IC. As most LV (low voltage) supply voltages in TVs are derived from a common regulated source, this would imply that the power supply circuitry itself may be faulty - dried out electrolytic capacitors being prime suspects.

However, as with any fault in complex circuitry such as this, there may be other causes including less logical ones such as dry joints or shorts in wiring or between PCB tracks.

Nov 23, 2009 | Sansui Televison & Video

1 Answer



The simplest would be to connect the power supply to a motherboard since this is where the on/off switch is also connected. The power supply needs to be triggered on before it will operate. Plugging in power from the mains is not enough.

Alternately in most PC power supplies, you can try force triggering to turn it on with just your fan and lights connected. This is done by shorting the Green (or Gray in some) wire to the GND (black) wire on the biggest connector.

In most modern power supply designs, it needs a load across the +5V rail (latch on) to operate otherwise it will power on but then immediately switch off when it senses that there is no load connected. Sometimes this can be defeated by shorting the Orange (Power Good) wire to the Red (+5) wire.

A word of caution, some old Dell power supply as well as a few other brands do not follow the standard wiring color coding

Hope that this be of some help/idea. Pls post back how things worked out or should you need additional information.

Good luck and kind regards.

Hope that

Dec 08, 2007 | Computers & Internet

Not finding what you are looking for?
Computers & Internet Logo

Related Topics:

33 people viewed this question

Ask a Question

Usually answered in minutes!

Top Computers & Internet Experts

Les Dickinson
Les Dickinson

Level 3 Expert

18424 Answers

Doctor PC
Doctor PC

Level 3 Expert

7733 Answers

David Payne
David Payne

Level 3 Expert

14162 Answers

Are you a Computer and Internet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides