I'm getting 165 volts on q1 & q2 on the power supply of a loud technologies power supply board ( model srm 1801 but no other dc voltages and all three legs of q11 are showing a short I can

do you have a diagram or are you just winging it?

You need to use a ESR meter to check capacitors

The computer's switch mode power supply produces DC (direct current) electricity.

( "Power Supply Problem Not Switching "???? )

How do you know it's Not Switching? Do you mean the TV wont turn on when you push the power button on and off on the TV and also with the remote control unit? Is that what you mean? If YES! Then, If your Vizio TV wont turn on and has NO-PICTURE, NO-SOUND and a BLACK SCREEN, Then the TV has an AC or a DC Voltage Problem.

1 - First, check the wall outlet socket by pluging in a lamp to see if you have 110 AC-volts there. If the lamp works, the wall outlet is OK! That means the problem is inside the TV.

2 - Before, you remove the back off the TV. I want to *(CAUTION - YOU)* The Power Voltages inside your TV are Very, DANGEROUS!!! There is 110 AC Volts at a 20-AMP-Rating ***CAN BE A LETHEL DEADLY SHOCK HAZARD to HUMANS!!!*** Also there are DC Voltages ranging from 3.3 to 24 volts. And R-F- VERY-HIGH-VOLTAGE of 20,000 Volts or More.

3 - You will need hand tools and a Digitle Volt Ohm Meter to check AC & DC Voltages and the OHMS Meter section to check resistors, capacitors, coils, grounds and contacts.

4 - With the Back removed, and no-power to the set. Inspect the power board for any signs of BURNED, LOOSE or BROCKEN parts like resistors, capacitors, coils, fuses on all boards. If you discover damaged parts, make a list of them. Then you must deside if you are qualified to do the on board repair or just order a new replacment board.

5 - If on the other hand you didn't discover any damaged parts by your inspection, It's time to put the Meter to good use. Plug the TV power cord to the wall outlet. Set the Meter for AC - voltage range of 200 or more. check for 110 AC volts going to the power supply board fused inputs.
If NO replace the cord. If YES, look on the board for voltage test points marked on the board. (SAMPLE!) 3.3 vdc, 5 vdc, 12 vdc, 24 vdc, and so on. Set Meter for DC Volts now, range 50 to 100. Put the black lead to ground and the RED lead to each test point marked on the board while repetetedly pressing the TV power on & off button..

6 - If ANY of the DC voltages were LOW, WRONG or MISSING, The Main power board is defective and needs to be removed and replaced with a new one. Write down the board number that is on the board and use that number to order the new one. You can order it on the Net!

*****(NOTE)***** If you are not an electronics tech. don't try to fix the old defective board... but, keep it handy, you might need it for parts later. :-)

Hope This helped... GOOD LUCK! NOW, GO FIX YOUR TV!

Likely the amp blew and the power supply is being overloaded and keeps trying to power on but finds an overload and continues as the power goes away. This is NOT a DIY unless your are electronically adept.

Download the schematic at:

http://elektrotanya.com/mackie_1604-vlz_mixer.pdf/download.html

Scroll down to the link to download that says "Get Manual"

This is for the 1604 unit which is just a truncated version of yours. When downloaded, find the phantom power supply on page 18.

There are too many components to guess which one so best just to troubleshoot.

I would even suspect the phantom switch since they have POOR design with no inrush current limiting when charging the input capacitor. Since the 48 is not individually fused, if the inpout cap C3 shorts, it probably will take out the switch or the diodes.

Another user had the Zener D9 fail which would cause the problem. Meter the voltage across C3 (probably about 60 volts) and D9 and C4 (47 volts). First check C4 as that cap is run TOO close to the rating of 50 volts... poor design... C5 would also be suspect... or Q1 and Q2.

Then it gets dicey as there are UNDOUBTEDLY many bypass caps in the mixer portion of the board.

http://www.google.com/products?q=advueu+power+supply&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&ei=zJ4hS_mFBMuBnQeetMTxCQ&sa=X&oi=product_result_group&ct=title&resnum=4&ved=0CCAQrQQwAw


Advueu ADV178B LCD Monitor POWER SUPPLY CORD
19V AC power adapter for Advueu Technology EZ18A LCD monitor
Adapter Type: LCD monitor power supply

Input Voltage: 100-240VAC (50-60Hz)

Output Voltage: 19 Volts DC

Amperage: 3.16 Amps
Price: $24.99

· Scanner home position sensor failure
· Defective scanner motor
· Defective main board
· Defective dc power supply board
· Incorrect scanner drive wire position
· FU202 on the dc power supply board open (blown fuse).
- Action -
Turn the main switch off and on.
Check the position of the 1st scanner sensor actuator.
Actuated De-actuated
Does the scanner motor rotate when the main switch is turned on?
No Yes
Correct the scanner drive wire position.
Check the voltage at CN106-2 on the main board.
24 volts 0 volts
Check FU202 on the dc power supply board.
Good No Good
Replace FU202
Replace the dc power supply board.
Check the voltage at CN105-1 and 6 on the main board.
24 volts 0 volts
Replace the main board.

generac was purchased by Briggs Stratton some years ago, however some information is available at the following web address, just enter your model number:

http://www.generac-portables.com/service_support/owner_manuals/owner_manuals.cfm

The small board that you describe is the bridge rectifier that converts ac from the windings to dc for the armature. You can test the brush/board by removing the part from the generator and applying 12 to 16 volts ac to the input tabs/wires then test/read dc (dc voltage will be lower than input ) voltage at the brushes. Use meter to make sure that you are getting dc. I use a small power supply less than one amp that I purchased at the thrift store for a couple of dollars. If test fails replace part. If it tests ok re-install brushes and re-connect the ac power supply to brush/board which in turn will energize the armature. At this point test the armatrue for magnetic power. I use a thin welding rod or wire against armature. If you feel a magnet start the engine. If the windings are good you should get some voltage at the plugs and the two wires that feed the brushes (will not be full voltage). If voltage is present, kill engine and disconnect ac power supply and connect the original wires to brushes/board and start engine. If you now have voltage at plugs you spiked the system indirectly by energising the armature. If still no voltage you may have an open circuit that feeds the brushes or diode pack is failing with the incresased voltage. Good luck with your repair and email if you have questions.

Q1 - Possibly, I have not seen an SC581 error before. Usually using too much power would give you something like an SC240 error "Power Supply Excessive". So it depends on the extent of the damage. You could also have to replace the main board, motors, etc.

Q2 - You will have to pull back the feeder tray, remove the back panel, there is a cover over the main board and the power supply is below it and fairly easy to get to. But if other components were damaged it could be a much more involved repair.