Lg42lb5 no voltage on PS board except for input cord.
-
-
Re: Lg42lb5 no standby or turn on
Here is psupply pictures, I have no voltage at the 5vs or anywhere, what could be bad.Attached Files -
-
Re: Lg42lb5 no standby or turn on
No voltage on main filter capsComment
-
Re: Lg42lb5 no standby or turn on
so there is really nothing on those 2 big black caps on the bottom? Make another picture of the backside of the PSU.Comment
-
Re: Lg42lb5 no standby or turn on
No voltage on two large capsComment
-
Re: Lg42lb5 no standby or turn on
Back side of psAttached FilesComment
-
-
Re: Lg42lb5 no standby or turn on
check fuse F101. If that is ok, check the bridge rectifier (4 legged thingy mounted to the heat sink).Comment
-
Re: Lg42lb5 no standby or turn on
Fuse is good , how do I test the rectifierComment
-
Re: Lg42lb5 no standby or turn on
Youtube: test bridge rectifierComment
-
Re: Lg42lb5 no standby or turn on
Bridge rectifier tests goodComment
-
Re: Lg42lb5 no standby or turn on
then you should have ~170V DC on the big main filter cap, when you plug the PSU in. Be very careful on the primary side, there are lethal voltages.Last edited by CapLeaker; 08-22-2015, 05:35 AM.Comment
-
Re: Lg42lb5 no standby or turn on
I have 118v coming in bridge rectifier and 102v DC leaving it. Test the two main big filter caps have 0 volts DC.Comment
-
Re: Lg42lb5 no standby or turn on
Not sure what's up with your meter, but a 120V AC gives a 170V DC. Maybe your battery is almost dead.
You have to chase the Positive path from the bridge rectifier to those big filter caps. Set you DMM to DC put the negative to the negative on the bridge rectifier and the positive to the pad EL129. Then take another measurement on the other side of R509. Just don't slip with the leads!
What is your board number? Starts like EAY and some numbers.Comment
-
Re: Lg42lb5 no standby or turn on
Update: rechecked bridge rectifier in diode mode and from outside leg measures 580 to next leg and 560 to the next and from outside leg to outside leg it measures 1400. I think its out of range , from what I see should be 400-700, gonna take out of circuit and testComment
-
Re: Lg42lb5 no standby or turn on
That's not good. Check it out of circuit and replace it if you have toComment
-
Re: Lg42lb5 no standby or turn on
Bridge rectifier tested out of circuit good same as a new one. Put new one in, same thing.Comment
-
Re: Lg42lb5 no standby or turn on
and what's with all the other stuff on post 13?Comment
-
Re: Lg42lb5 no standby or turn on
I have 102v from + bridge rectifier to el129 and R609 but zero v from - of bridge rectifier to those points. I have 102v at both filter caps from + of bridge to filter capsComment
-
Re: Lg42lb5 no standby or turn on
Board is eay32731102Comment
-
Re: Lg42lb5 no standby or turn on
Anybody?Comment
-
Greetings!
Thank you in advance for your understanding, I am writing to you through a translator.
A Harman Kardon AVR171S amplifier was given.
The history of the machine is as follows:
It was faulty when I bought it, I want to fix it.
I replaced the HDMI switch and one of the DAC ICs in it.
After that it worked without a problem.
I watched a movie using the amplifier, and at the end the amplifier got really hot.
The cooling was faulty, I will fix this later.
I switched it to standby mode, waited for... -
Hello, i have some issues with my laptop Lenovo Y700-17ISK (motherboard BY511 NM-A541), it started when i turn on the laptop, but the lcd wont turn on, i then connected it via hdmi to tv and screen was ok. So i thought maybe lcd stripe is faulty, i removed the bottom cover, disconnected main battery, reset the cmos by disconnecting battery for 1 min, then slighty move the lcd stripe. Conncted power supply and tuned on my laptop, the lcd turn on, it started to load os, then it turn off, after a second it turn on, then after like 3 seconds turn off again, and so on. Removed power supply, waited... -
My Samsung LN32B540 never turned back on after I had to turn off the power at the mains at house. It won't turn on, but the red standby led lights up when it is plugged in. If I hold down the power on the remote, the standby light turns off which I think means it is trying to turn on, but there's no sound or backlight. If I try to turn it on/off from the power button on the TV instead, it doesn't do anything at all.
It was plugged into a surge suppressor and was off (on standby) when I turned off the power,, so I don't know if it got a power surge or was on its way out anyway. I... -
Hello,
I need advice in troubleshooting Telefunken TV (it is actually Vestel). There is red Standby light but TV cannot be turned on either by remote control (which is good and tested on another TV) or by actual on/off switch at the back of the TV.
Power board is Vestel 17IPS71 and I'm not sure about the mainboard, it seems like 17MB82S
Both boards are shown in the attached photos.
What is normally first that is checked in this case. I have removed power board, make sure it has no dangerous voltage on the big caps and check many components (transistors and diodes)... -
Hello everyone!
I'll try not to create big posts this time (though I'm sure I'll fail).
Ok, here we go...
Back in 2017. one capacitor on my monitor power board failed, so I had to replace it. I decided to change all the caps (except the BIG one), and everything was working well. I had a big help from other members, especially from momaka. He had enough patience to give answer to all my questions.
For those interested in reading that topic, here it is: [help required] which capacitor type for monitor power board
...
Comment