No 3.4 volt output

It is dependant on how many LED's are present in the back light LED array. IT can be 35 to 60 volts. In most cases the power unit does not fail, the LED's do because they are pushed to their maximum output for the illumination of the screen. All it takes is one LED to go bad and the rest wont come on. The diagrams for the unit are not posted

Confirm power is availible at starter main power supply, step one , using mutl meter check for 12 volts at battery positive terminal , 2, check main voltage supply lead to starter from battery pos post , 12 volts present? yer check voltage supply lead from battery pos post to altenater , then to starter , 12 volts present, yes , check small wire to starter at starter for switched 12 volts present yes change stater after confirming suitable ground, no, trouble shoot ignition / starter switch in colume

Check the voltages of a 4 pin connector with a multimeter.
The 5 volt will be on the red and black wires.
The 12 volts will be on the yellow and black wires.
If the voltagws are not present or wrong then the power supply is faulty and needs to be replaced.
When you replace the switch mode power supply, make sure the total wattage of the new power supply is equal to or greater than the old power supply.

the power supply of your TV must be check.the power output of the power supply suppose to be 12 volts for audio,24 volts for the backlight lamp and 5volts for the main CPU. use a multimeter to measure the voltage In the case of your TV it seems only 5 volts is present that is why you have a power indicator lit....open the back cover of your TV and measure the power supply.power supply board is where the power cord is connected...

Is the fuse located before or after the main power switch?

If the answer is before the main switch, then maybe you should also check the main power switch (dirty contacts - these may cause insufficent voltages from the power supply).

Note that the (electrolytic) capacitors can be faulty but will not have visible damage, so check the DC voltages on the power supply output and try to replace the associated capacitors if the voltages seem to be too low (usually, there will be 12 and 5 volts outputs, sometimes a 3 volt output on some brands/models).

If it turns out that these voltages are not present at all, then there may be damage to the transformer driver IC (i'm assuming this is a switching power suply) - see if there is any AC voltage present at the secondary terminals of the transformer, if there is none, then the primary is most likely not being driven by the 110 V and this points to the driver IC as the possible cause. It may also be some other component in the primary section, but you said you've checked them out, so i don't know what else to suggest.

Hope you can fix it.

regards

Triarcuate

OK you need a volt meter to check the voltage output of your power pack as two things cause this now enough power out the pack to run your unit or the unit has a short both problems will unlight the light so you need to know if the power supply is working right first as it should say like 120 volts AC in and 12 volts DC 1000 ma out so you will need to mesure this with a volt meter. this is a common problem loading the load of the curcuit as in your TV is mor the the power pack is giving out thus shorting out the power pack of any voltage present, as the little LED light your seeing only takes 5 volts at very ittle current to light and dose not repersent the total voltage output of the power pack itself

Hello rcgibson, output of charger for (if this is correct 'Roadmate 800 GPS unit) AC wall power supply or 12/24 volt DC is 5 volt at 455 milliamp.

Try these test, the only common possibilty would be the transformer and the power supply if both channels are out.You better to check both the positive and negative voltages from the power supply to see if both are present or if one or both are missing.This would be dc voltages of approx.20 to 40 volts.The positive voltage must be equal to the negative voltage,with the exception of their polarity.If one higher than the other, the regulator in power supply is busted already.The transformer can be checked for AC voltage before the power supply.This reciever uses a single power supply so the problem would be,common to both channels.You better change the regulator and checked some capacitor near the regulator.

I think you missed one cap. Look for another 1ufd cap close to the jungle chip. It will have the circuit designation in the 300's like the others in the vertical circuit. It is just not located close by. I think that one will fix it.I don't have the service data with me so I can't give you the exact designation.
Dan

verify your b+ voltage on collector of horizontal output transistor 7405 and if 130 volts is missing or way off go to power supply circuit and verify voltage on pin 14 of ic 7511 and if there is not approx 150 volts present should replace that ic and startup capacitor 2511 and opto isolator 7513. if 130 volts is present on collector of 7405 then scope signal on 7404 and if not clean signal replace micro processor