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Re: Sharp LC-32sb28ut Power Supply has Pulsing DC Voltages
Is the PS-ON on main board pulsing too?
I cannot think of any way it is not the power supply. Perhaps it is a common fault. Or even what it does in standby, for example to save power?!Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: Sharp LC-32sb28ut Power Supply has Pulsing DC Voltages
The pin labeled "PS" on the power supply, which looks to
be the PS-ON, pulses from 3.1V to 0 V, again in time with
the blinking blue LED.
This PS-ON signal comes from the main board, right? So if it's pulsing,
perhaps that is why even the big main filter cap is pulsing as well,
because all it's doing is ramping ON and OFF.
Bummer, but perhaps I have two good power supplies I can sell....Comment
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Re: Sharp LC-32sb28ut Power Supply has Pulsing DC Voltages
That makes sense.
If it is anything like the cheap made in China TVs I have serviced, they will begin the power up, "crash" due to a fault, wait a few seconds then restart. Hence the pulsating DC, the entire PSU is being switched on and off. This isn't a real Sharp, so they haven't designed it well -- a good Sharp would go into lock out, blink an error code and everything would hopefully be easy to locate.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: Sharp LC-32sb28ut Power Supply has Pulsing DC Voltages
Man, I feel bad not asking you to check the PS_ON signal!Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: Sharp LC-32sb28ut Power Supply has Pulsing DC Voltages
Yeah, it's amazing how you can veer off into the wrong
path completely!!
BUMMER!! Oh well, at least I can sell two good power supplies now!
And the inverter board is probably ok too, but I've had bad experiences
with Ebay buyers lately, so maybe I'll hold off......haha!Comment
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Re: Sharp LC-32sb28ut Power Supply has Pulsing DC Voltages
Yep, I missed this one right here" Then I checked the +5V when I first plug it in (Red LED standby
mode), and it was at +4.1V" The main board is drawing too much current form the standby power supply (or the standby is not steady since it is not controlled by the PS_ON). It is not easy sometime when you do not have the board in front of you.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump
One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy... -
Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hello everyone!
I have this board that got slightly water damanged and it is stuck at S5 state. It pulses once every 5 seconds.
When connected the magsafe 2 to the bench psu, the current goes from 0.02A to 0.10A when is pulsing.
When using the genuine magsafe 2 charger, the light turn on and it became green and then amber. The fan is not spinning.
When I tried the SMC bypass mode, the fan spins a quarter every 5 seconds and the pulsing is still present every time the fan spin.
The pulses are present in the CPU Vcore rails on L7320 and L7310.... -
I have been working on this concept for quite some time now with limited success but recently I found a switching power supply that is setup for the voltage that this soldering station needs to operate at however it also needs part of the secondary circuit from the original switching power because you need several voltage rails
I once tried to get a ZD-915 desoldering station to work on a 18 volt battery power supply but unfortunately things did not go well but I did find a work around but I might try this idea again but going at a little differently more about this another time... -
Hi Guys
I Have this Samsung smart tv that needs repair.
with everything connected i get pulsing A5V at the PSU connector. if i unplug the main board then all voltages pulse on the output connector.
I dont get any voltage on the LED connector.
there is also an audible click around the mosfet marked below
The connector to the Buttons all voltages pulse (3v)
I have searched and found a similar problem but there was a stable 14v, but was also not repaired.
I checked and replaced the mosfets with no effect.
Any ideas where...
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