MS9700 secondary voltage

I would investigate what voltage the transformer connects to for primary and what voltage devices connect to secondary. Bring in a temporary power source and read the amperes it draws to operate and find the product of secondary volts and amps to select a new replacement txr

All transformer comes with a current limit specification in terms of VA units. For example a 24 v secondary coil with 6 VA specification only can hold a current of of 4 amps for a short period of time. So to prevent that it burned out you only pass an 80% of that current, then it really can hold 3.2 amps continuously.
Other possibles causes for burning the transformer are:
1. Accidentally connecting the primary and secondary reversed, the secondary can not manage the voltage and current of the primary .
2. A coil or device that is connected to the secondary is demanding to much current because is shorted or stuck in a position causing an increase on current.
3. The primary have multiple taps to operate on different voltages and the combination is wrong.
3. Faulty wiring. Some times the insulation of the wires became worm, cracked or melted, with the wires torches the metal a short is produced and the transformer burns. Check the wires carefully.

Hope these tips help,.

the usb output is off course 5 volt. Your phono output you can measure with a reasonable meter, depends on the needle and your line output is something you really need to know , since it's a constant , just like usb which has four leads. Two with a constant voltage 0-5. and the other two are for data transport.

You have not mentioned the details of the machine in question. All you need is to check on the LT ( low voltage side ) of the transformer to find the secondary voltage which will be about 20 to 30 % less than the DC voltage shown on the capacitor on the board. If there are more windings then you can get the primary rewound without any changes to the secondary that must help to solve.

1. 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.
   
2. 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.
   
3. 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.
   
4. 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.
   

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

High voltage circuit .......be careful Don't. work until you know how to use multimeter Never try to check the secondary volage across the transformer.its very risky Just check the primary voltage at the transformer if you know how to do it otherwise just leave it If you know how to use multimeter then let me know Thanks Please rate me

Doing a resistance test on a transformer will not give the information you require as you will read very little, if any resistance. What you need to do is an impedance check and that gets involved. If it is a normally wound transformer, not an auto transformer, you can isolate which is the primary and the secondary windings. Unless the transformer is a multi voltage input unit, the primary side will have continuity through only two terminals. The secondary could be more than two if it is a multi output voltage one. If the transformer is a step down, the primary windings will be the thinner wired windings and vice-versa. To actually test the transformer, get hold of a transformer with about a 20 vac output and try it across the two terminals you have identified as the primary windings, you should ge a proportional voltage of the actual output. eg. with 20 vac input and a 2 vac reading at the secondary, the actual output would be 11 vac if your mains voltage is 110 volts. Take care that you are using the transformer at the voltage it is designed for, otherwise it will overheat and burn out.

Transformers USUALLY don't get burned as they are usually protected by a fuse. This one supposedly uses a 3 amp fuse which should have protected it from getting burned. If you can find a schematic or if you can find the specs on the output amp power supplies we can probably calculate the voltage of secondary. We know only that it is supposedly 120 Watts and uses an 8 ohm speaker. The RMS voltage should be about square-root 120*8 = sqrt 960 = 31V*1.4 = approx 44 volts peak... so you will need to get about +/-45 volts out of the supply for headroom... which will need approximately 34 volts AC given diode drop and droop of filter caps. These are really rough educated calculations from the tiny bit of info we have.
Finding a transformer to replace this matching these requirements will be near impossible without getting device from the original manufacturer OR having your rewound.
I would first verify the transformer is bad (only plausible cause is somebody over-fused it or a winding shorted)... Remove all the secondary loads. Put a 3 amp fuse in AND put a 60 Watt light bulb in series with teh power cord to act as a limiting device to test the transformer... Note that transformers DO have a bit of odor as they are usually impregnated with a varnish...

Hello,The transformer (breaks) if the secondary is shorted for any reason.Also a power surge to the house/building will kill it (lighting strike/car hitting telephone pole).It might cause damage to the board.It is cheaper to try a new transformer BUT add a inline 3 amp fuse in the secondary so that will be the last transformer you have to replace(just fuses)if the short is hard to find.Power up the old board & see if it works,unless there is obvious damage.The plug sometimes comes with a new board because there is a wiring change to install it(on some) replacement boards.