Hi everyone - Just thought I would share a few details about the repair of my LP3065 power supply. The monitor would exhibit the 2 seconds to black issues detailed in other posts. I tested the CCFL lamps via an external supply and found all 9 sets to be working OK. I tried to replace the inverter board (salvaged from a Dell 3008) and still no-go. I then removed the power supply for testing independent of the monitor. I found that you have to load the output voltages to properly test the unit. I used resistive loads for about a 1 amp load on the 5VSB, 18 and 24 volt outputs. This supply uses an L6561 Power Factor Correction/boost regulator (8 pin SOIC in one corner of back side of PC card) just beyond the bridge rectifier to provide a V+ of about 400 Vdc when properly functioning. The 5VSB supply is developed via an SG5842 IC(only other 8 on SOIC on rear of board). The +18 and +24Vdc outputs are developed via the L6598 IC on the top side of the PC board (16 pin dip partially hidden by heatsink plate). I could read some of the part numbers on the ICs. The others I read under a microscope while bathed with isopropol alcohol. As the alcohol evaporates there is a short interval where the alcohol in the depressions of the part number remains so you can just make out the number for a few seconds. In the end the problem with the supply was an open resistor in a divider network that supplied a half wave signal to the L6561 from the bridge rectifier which made the L6561 unstable and the supply would cycle on and off. I put a lot of effort into reverse engineering the design and creating schematics as best I could but I don't trust them enough to publish them. I want to close with the typical cautionary statement - Please be careful if you're going to work on the HOT side of SMPS devices as the results of any mistakes can be fatal.
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Re: HP LP3065 Power Supply Details
That is why I recommend to use Isolation transformer (Neutral NOT tied to Ground on the outlet) for the UUT specially if you are going to use the scope on the Primary side of the circuit, and at least plug the UUT into GFI outlets.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=24809 -
Re: HP LP3065 Power Supply Details
Thanks for sharing! I don't suppose you would remember which resistor id it was, Rxxx, or what value it was?Comment
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Re: HP LP3065 Power Supply Details
R102 - 620kComment
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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... -
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... -
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 all, I just need to know that, can i use SMPS type power supply to test and short circuit detection on a laptop motherboard?
I saw 95% of repair guys are using only Linear bench power supply. linear bench power supply is pricy, thats why i planned to get one SMPS supply.
i know that in linear power supply the noise will be very low comparing to SMPS supply.... -
Hello Everybody,
Trying to repair a power supply from a Russound CA4 Multizone Controller (picture attached)
Russound no longer supports it but were kind enough to provide a schematic of the power supply (pdf attached).
The outputs marked 12v and 20v are all measuring only 1v.
The board is clicking, which I think means it is in something called hiccup mode when the flyback transformers switches because of an internal problem or something else on the board Overloading it.
The capacitors physically look clean (no bludgesor leaks) and...
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