How to test for bad transformer - Emerson LC320EM8 32 in. LCD TV

I would suspect bad transformer. The board may not have a light because it is not receiving low voltage from transformer. With a multimeter you can test the transformer. But, since you likely have a short somewhere be sure to install a fuse right after the transformer or you will be burning up another transformer until you figure it out.

If you check between the power source and the transformer you may find it, but if you didn't then you would have to change the transformer. it is bad.

If and this depends on brand and model number, the output transistor is shorted confirm the voltage from it to the transformer and if being held down or High voltage only comes up to 5 or 6 thousand volts the flyback is suspect.

Most shops of course have a ringer which will with part out of set test the primary winding (one that goes to and from the sweep transistor).

Some models are more prone to bad transformer than others so look at the history of this brand/model.

A bad one will usually take the sweep transistor out sometimes repeatedly--but other issues in for example the driver circuit in some models will cause the transistor to pull excessive current and get hot very fast---not usually the transformer.

Two basic ways--most shops use a ringer---with flyback out they connect across the primary (where sweep transistor collector goes to where that lead on the transformer exits--a good bad indication is seen.

Second way is voltage into the transformer is tested and High Voltage is measured at the CRT---usually if transformer bad you will have 4kv or so (4,000 volts) and the suspect is clear.

If HV just comes up full (over 20 Kv) and drops to zero it is not the problem and something is shutting the set down.

First, check the 220v line and breakers are properly grounded and that you are getting a constant 220v at the plug. Then you will need to check the transformer on the unit.To test a transformer you need to know what type of transformer it is first. There is a step up transformer which steps the voltage up and a step down transformer which steps the voltage down.
You will still test the transformers the same way for step up and step down transformers. If it is a step up transformer apply the incoming power to the transformer or plug it up. Now take your multimeter and place it on the AC volt scale and test the voltage if the voltage on the data plate says the transformer should step up to 220 volts and it doesn't then your transformer is bad.
Now repeat the same steps for a step down transformer. Plug up the incoming or primary power and test voltage on the outcoming or secondary side the voltage should step down to the proper value. If you don't read any voltage on the secondary or outgoing side then the transformer is bad.
To read the voltage place the two meter leads on the secondary side, or the side you will plug your equipment into. If the secondary side is an outlet then place the two meter leads into the top two slots in the plug and read voltage. You also want to make sure the incoming power is working as well. Otherwise you will be reading a bad reading every time.
If all that looks good, then you will need to replace the control board. Here is a link to the parts for your range.
Regards,Richard

Hello, most common faults, such as CRT TV will not turn on. The reason stems from the low power supply failure, or from the high power supply. There are two transformers suppliers, with more common high-tension transformer goes bad. Price of 80 or $ 100, sounds reasonable replacement of transformer. Along with this need to perform some tests that require a professional, to confirm that the problem is due because of transformer. One test is to test basic stability, voltage power reaching the high-voltage transformer. If lower than normal voltage. Then perform the same test, when you break the initial snap of the transformer. If the voltage rises to the desired level must be to replace the high voltage transformer. Good luck!

You could be correct on the transformer. I'm kinda leaning towards a bad cell in the battery. Sounds like it will need replacing.

then you need to replace the transformer.If you are not sure that the transformer is bad just use a multimeter to test it. There are a lot of helpful websites that have step by step instructions on how to test them, but in most cases if a transformer is bad you will see burn marks on it.