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I have a Mackie SR40.8 audio console. The power supply led voltage indicators show that all voltages are present (-17.4, +17.4, +5, +12 and +48). When I connect the power cable to the console, the -17.4 volt goes missing while the power supply led indicator for -17.4 (or -18v) is still lit. I removed all of the attached ribbon cables to the power distribution board (055-077-00 REV) but no lasting change. Sometimes it may appear and then dissapear. Help!!! Is the -17.4 volt MOSFET (Q2) failing, the op amp or diode(D2) is bad or a capacitor is shorting on the power distribution board?

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6 Suggested Answers

6ya6ya
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SOURCE: Model CF1926A TV with insufficient

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

Posted on Jun 04, 2008

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jaedon_jacks
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Try a different usb cable or mabey the actual usb port

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gewiz
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SOURCE: shop rider sovereign voltage indication. Brand new fully charged

hi Richard,

Does the scooter actually lose power after the 3 leds show ?

If it is losing power then a suggest to try some other batteries to confirm dodgy batteries, check the terminal connections etc.

If it does not lose power then the volt meter is at fault, if you can check the voltage before riding then after it shows only 3 leds , if there is a big drop, check the charger first to make sure the batteries are getting fully charged.

Regards
GeWiz.,

Posted on Dec 21, 2009

budmrtn
  • 11361 Answers

SOURCE: we have samsung LCD with

So the standby 5vdc is working but not the rest of the power supply outputs are working? Look for PS_ON signal (3.3~5vdc for ON) from the main board that feed the power supply board. You can tak ethe power supply moudule out the do bench test using 24v lamp attach to the 24vdc out put and feed the PS_ON with 3.3v to see if the 24vdc will turn on.
Basic LCD monitor and TV troubleshooting guide:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting
http://www.fixya.com/support/r7406380-tv_training_manuals
Failed TV and Monitors pictures: http://s807.photobucket.com/albums/yy352/budm
Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague
Parts: www.shopjimmy.com
Parts: http://interliquidparts.com/

Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps.
Or www.digikey.com, just make sure to use caps with low ESR, 105c, high ripple current and long life rating such as PANASONIC FM or FC series.
Please post back what you find.
I have a feeling that the main board is damaged since the protection Diodes are blown, it may have taken out the processor.

Posted on Jul 01, 2011

jeffsterrett
  • 108 Answers

SOURCE: I have lost my power

24V DC, 2.5A

pg 7 of User Manual

http://download.p4c.philips.com/files/d/dc910_37/dc910_37_dfu_eng.pdf

Posted on Sep 15, 2011

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LG TV 39LN5300 - What is normal voltage at LED connection to power supply?


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Can you help me troubleshoot my TV? It has audio but no picture.


Use a voltmeter to confirm all the voltages are present when the TV is powered on. If they are all correct then replace the led driver.

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LG 42LN5400-UA.BUSYLHR back lights not working, sound working, flashlight test shows video working.


This is a common problem for LG 42LN5xxx & 47LN5xxx LED TVs, the problem is defective LED back lights strips, it has nothing to do with main power supply & the main board.
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Lg 50LN400-ua is the led driver on the power board


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My new visions t9550 treadmill will not calibrate. it completes the speed calibration but treadmill will not elivate therefor fails calibration. what do i do?


Step 1:

follow this steps for troubleshooting and fix it. God bless you

The SCR lower board is designed with diagnostic LED lights. The LED's are color coded according to

their specific function. Green indicates a properly operating treadmill; the green lights should always

be ON when power is supplied to the treadmill. Yellow indicates a treadmill function. Red indicates a

treadmill malfunction. Here is a list of each LED and what it signifies:

MOTOR (yellow) - The MOTOR LED illuminates when dc (direct current) voltage is sent to the drive

motor. The LED gets brighter when the dc output is increased.

RLC (yellow) - The RLC (R = Reactance / L = Inductance / C = Capacitance) LED illuminates when

the filtering system is properly working. The filtering system includes the capacitor and filter choke. If

there is a short in either component then the RLC light will not come on.

DN & UP (yellow) - The DN and UP LED lights tell us if the elevation DN and UP relays are

functioning properly. When the LED lights, it tells us that the relay has energized and is sending high

voltage (110vac or 220vac) to the elevation motor.

AC PWR (green) - The AC PWR (Alternating Current Power) illuminates when AC line voltage is

delivered to the treadmill. It then passes through the in-line fuse (110)/s(220) and lights the AC PWR

LED.

+12V (green) - When the proper AC voltage is delivered to the treadmill, passes through the in-line

fuse/s, through the full wave bridge rectifier (changes AC to DC), through the transformer (steps down

Step 2:

DC to +12vdc) then the +12V LED lights.
This the board LED, who control the signal for Main Motor+Elevation Motor. You must see, the LED DN+ UP( both will be Lit) in any position down or Up.

2) The RELAY board is designed with diagnostic LED lights. The LED's are color coded according to

their specific function. Green indicates a properly operating treadmill; the green lights should always

be ON when power is supplied to the treadmill. Yellow indicates a treadmill function. Red indicates a

treadmill malfunction. Here is a list of each LED and what it signifies:

AC PWR (green) - The AC PWR (Alternating Current Power) illuminates when AC line voltage is

delivered to the treadmill. It then passes through the in-line fuse (110)/s(220) and lights the AC PWR

LED.

VDC (green) - The VDC LED will light when it receives DC voltage from the DC power supply.

DN & UP (yellow) - The DN and UP LED lights tell us if the elevation DN and UP relays are

functioning properly. When the LED lights, it tells us that the relay has energized and is sending high

voltage (110vac or 220vac) to the elevation motor.

UPSW (green) - This LED will illuminate when the low voltage dc is delivered from the upper display

board to the elevation UP relay. This low voltage dc is what energizes the coil of the relay.

DNSW (green) - This LED will illuminate when the low voltage dc is delivered from the upper display

board to the elevation DOWN relay. This low voltage dc is what energizes the coil of the relay.

BELTSW (green) - This LED will illuminate when the low voltage dc is delivered from the upper

display board to the belt (motor start) relay. This low voltage dc is what energizes the coil of the relay.

SPD (yellow) - The SPD LED flashes on and off (relative to speed) when the speed sensor is

operating properly.

PWM (yellow) - This LED will light when the upper board is sending a speed signal to the PWM.

Both the PWM LED and BELTSW LED must be lit for belt movement.
Finally this this Relay Board, the Each Led will be Lit, for any Relai control for DN down, or UP for elevation Motor. You must clean contact of the Relay with Special Spray(Radio Schack).

With this you must fix it.

Step 3:

Try this again. and fix it.b) LUBE the gear motor, shaft and turn the POT a little and see if the motor get RPM.

The Steps for Newer Style Console Calibration:

  1. Locate the calibration area on the rear or underside of the console (a hole, near the console's center, that goes through to the electronics board. (This hole should not have a screw in it.)

  2. Insert a pencil (eraser end), into the hole and feel around for the cal button (will click when pressed).

  3. Press the button 2 times (with the pencil eraser). The first click should show CL11 in the console, the second click should show CL21.

  4. If the process was done correctly, and CL21 appears in the console, you are in "calibration mode." The next few steps consists of pressing buttons on the console and observing settings. This will not require any other tools.

  5. Press ENTER. CL22 should display in the TIME window and (??) in the SPEED window.

  6. Press ENTER. CL23 should display in the TIME window and (??) in the SPEED window.

  7. Press ENTER. CL24 should display in the TIME window and (??) in the SPEED window.

  8. Press ENTER. CL25 should display in the TIME window and (??) in the SPEED window.

  9. Press ENTER. CL26 should display in the TIME window. You should then see the letter "E."

  10. Press ENTER. You should see "SS" or "55" in the console.

  11. Push the STOP/START button. For safety, at this point, you should step off, or be off, the treadmill.

  12. Push the ENTER button. The walking belt should start to move, accelerate to maximum speed, then stop on its own.

  13. When the belt stops, the incline should self test by raising to its highest incline position, then lowering back down to its lowest position.

  14. Once the incline test is complete, push the POWER button 2 times. The unit should shut off and the console should go completely blank. If this happens, the treadmill is done calibrating and is ready for use.

  15. If the letter "F" appears in the SPEED or INCLINE window when the power button is pressed 2 times, the treadmill is indicating a failure somewhere either in the SPEED or INCLINE (depending on the window the "F" appeared in).

1_7_2013_8_21_43_pm.jpg1_7_2013_8_22_06_pm.jpg

Jan 07, 2013 | Vision Fitness T9550 Folding Treadmill

1 Answer

Initial calibration keeps failing. the treadmill will not elivate


Step 1:

please see this test and fix it. God bless you

The Steps for Newer Style Console Calibration:

  1. Locate the calibration area on the rear or underside of the console (a hole, near the console's center, that goes through to the electronics board. (This hole should not have a screw in it.)

  2. Insert a pencil (eraser end), into the hole and feel around for the cal button (will click when pressed).

  3. Press the button 2 times (with the pencil eraser). The first click should show CL11 in the console, the second click should show CL21.

  4. If the process was done correctly, and CL21 appears in the console, you are in "calibration mode." The next few steps consists of pressing buttons on the console and observing settings. This will not require any other tools.

  5. Press ENTER. CL22 should display in the TIME window and (??) in the SPEED window.

  6. Press ENTER. CL23 should display in the TIME window and (??) in the SPEED window.

  7. Press ENTER. CL24 should display in the TIME window and (??) in the SPEED window.

  8. Press ENTER. CL25 should display in the TIME window and (??) in the SPEED window.

  9. Press ENTER. CL26 should display in the TIME window. You should then see the letter "E."

  10. Press ENTER. You should see "SS" or "55" in the console.

  11. Push the STOP/START button. For safety, at this point, you should step off, or be off, the treadmill.

  12. Push the ENTER button. The walking belt should start to move, accelerate to maximum speed, then stop on its own.

  13. When the belt stops, the incline should self test by raising to its highest incline position, then lowering back down to its lowest position.

  14. Once the incline test is complete, push the POWER button 2 times. The unit should shut off and the console should go completely blank. If this happens, the treadmill is done calibrating and is ready for use.

  15. If the letter "F" appears in the SPEED or INCLINE window when the power button is pressed 2 times, the treadmill is indicating a failure somewhere either in the SPEED or INCLINE (depending on the window the "F" appeared in).


Step 2:

The SCR lower board is designed with diagnostic LED lights. The LED's are color coded according to

their specific function. Green indicates a properly operating treadmill; the green lights should always

be ON when power is supplied to the treadmill. Yellow indicates a treadmill function. Red indicates a

treadmill malfunction. Here is a list of each LED and what it signifies:

MOTOR (yellow) - The MOTOR LED illuminates when dc (direct current) voltage is sent to the drive

motor. The LED gets brighter when the dc output is increased.

RLC (yellow) - The RLC (R = Reactance / L = Inductance / C = Capacitance) LED illuminates when

the filtering system is properly working. The filtering system includes the capacitor and filter choke. If

there is a short in either component then the RLC light will not come on.

DN & UP (yellow) - The DN and UP LED lights tell us if the elevation DN and UP relays are

functioning properly. When the LED lights, it tells us that the relay has energized and is sending high

voltage (110vac or 220vac) to the elevation motor.

AC PWR (green) - The AC PWR (Alternating Current Power) illuminates when AC line voltage is

delivered to the treadmill. It then passes through the in-line fuse (110)/s(220) and lights the AC PWR

LED.

+12V (green) - When the proper AC voltage is delivered to the treadmill, passes through the in-line

fuse/s, through the full wave bridge rectifier (changes AC to DC), through the transformer (steps down

This the board LED, who control the DC to +12vdc) then the +12V LED lights.
signal for Main Motor+Elevation Motor. You must see, the LED DN+ UP( both will be Lit) in any position down or Up.

2) The RELAY board is designed with diagnostic LED lights. The LED's are color coded according to

their specific function. Green indicates a properly operating treadmill; the green lights should always

be ON when power is supplied to the treadmill. Yellow indicates a treadmill function. Red indicates a

treadmill malfunction. Here is a list of each LED and what it signifies:

AC PWR (green) - The AC PWR (Alternating Current Power) illuminates when AC line voltage is

delivered to the treadmill. It then passes through the in-line fuse (110)/s(220) and lights the AC PWR

LED.

VDC (green) - The VDC LED will light when it receives DC voltage from the DC power supply.

DN & UP (yellow) - The DN and UP LED lights tell us if the elevation DN and UP relays are

functioning properly. When the LED lights, it tells us that the relay has energized and is sending high

voltage (110vac or 220vac) to the elevation motor.

UPSW (green) - This LED will illuminate when the low voltage dc is delivered from the upper display

board to the elevation UP relay. This low voltage dc is what energizes the coil of the relay.

DNSW (green) - This LED will illuminate when the low voltage dc is delivered from the upper display

board to the elevation DOWN relay. This low voltage dc is what energizes the coil of the relay.

BELTSW (green) - This LED will illuminate when the low voltage dc is delivered from the upper

display board to the belt (motor start) relay. This low voltage dc is what energizes the coil of the relay.

SPD (yellow) - The SPD LED flashes on and off (relative to speed) when the speed sensor is

operating properly.

PWM (yellow) - This LED will light when the upper board is sending a speed signal to the PWM.

Both the PWM LED and BELTSW LED must be lit for belt movement.
Finally this this Relay Board, the Each Led will be Lit, for any Relai control for DN down, or UP for elevation Motor. You must clean contact of the Relay with Special Spray(Radio Schack).

With this you must fix it.





Step 3:

please lube the elevation motor, shaft, and gear, and adjust the POT for RPM, and see what happen. see the diagram + block diagram attached for troubleshooting and fix it.
God bless you
1_7_2013_8_26_09_pm.gif1_7_2013_8_26_56_pm.jpg1_7_2013_8_27_18_pm.jpg

Jan 07, 2013 | Vision Fitness T9550 Folding Treadmill

1 Answer

Good evening, I bought a second hand Mackie mixer 1604 VLZ-Pro, and I was not lucky. First of all I had to buy a new transformer which I already mounted. The problem is that after I turned it on all the...


With LED intensity changing with operations, that MIGHT be a symptom of the power supply going into current limiting mode.

The first thing I would do is to check the power supply voltages with an oscilloscope to assure that the voltages are stable and not dipping...

Now from my experience when I hear that a transformer had to be replaced that means it suffered over voltage or under frequency. I would IMMEDIATELY suspect that one or more of the rectifier diodes might be open. With only half wave into the caps the voltage will dip below what the regulators can handle giving weird effects. Check the +/- 16 volts with a scope that they are PURE DC and don't have ripple due to either damaged diodes or C6 or C7 being degraded. I assume you have a schematic... if you don't here is a link:

http://elektrotanya.com/mackie_1604-vlz-pro_mixer.pdf/download.html

Jan 28, 2011 | Mackie 1604 Vlz3 16 Channel Mixer

1 Answer

I tried several different cards but no luck. Cards work ok on other computers.


5V Stand-By Indicator LED
The power supply will always supply a 5V standby voltage to your
motherboard so that it can power on via for example Wake On Lan
technology. This LED shows that your power supply is supplying
this standby voltage to your motherboard.n :D

You may need to replace your power supply, if the LED is flashing, it's not supplying the power the motherboard needs.

[JP-25]

1 2 3 4 5 6 7 8 9
. . . . . . . . .
. . . . . . . .
10 11 12 13 14 15 16 17 18


1] Power Led (+)
2] --
3] Power Led (-)
4] --
5] --
6] Speaker (+)
7] --
8] --
9] Speaker (-)
10] Reset switch
11] Reset switch
12] N/A
13] Power Switch
14] Power Switch
15] ACPI Led (+)
16] ACPI Led (-)
17] HDD Led (+)
18] HDD Led (-)


For future reference you can download your motherboard manual here:
(PDF) Soyo K7VKP2

May 09, 2009 | Computers & Internet

1 Answer

42 plasma tv model42mf230a/37 blue light on no picture no sound


with solid blue led set could be still powering on but would need to verify by checking power supply voltages. if up and signal is present with no menu or audio would be ssb as audio amplifier, micro processor and eeprom are on that board. if voltages are not present you need to offload x and y sustain boards one at a time from power supply and check voltages and if vs comes up with either board disconnected replace that board

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