Re: Insignia NS-50P650A11 - Bad Power Supply?
A replacement power supply arrived today and the TV fired up right away upon installation. The VS voltage was almost 5 full volts high, so I adjusted that down right away. Then I looked at VA. The panel calls for 55v. The power supply was outputting 54v. I attempted to bring VA up slightly to match the specifications, but the little potentiometer seems unresponsive across it's entire range. [U]Very strange.[/U] Right now, the VA fluctuates between 53.7 and 54.3 depending on the picture on the screen (TV is fully warmed up). Is this an...
tds-1541
Member
Last Activity: 02-05-2015, 11:23 PM
Joined: 01-29-2014
Location: Madison, WI
-
Re: Insignia NS-50P650A11 - Bad Power Supply?
Thank you so much for that video. I was unable to get the power supply to stay on without leaving it plugged into the main logic board. I then jumped the PS-ON connector to ground. This forced the power supply to start. After bridging the jumper on the LVDS interface (top most jumper pair) and powering the unit up, I successfully got the multicolor test patterns to show up. The 15v rail was now at 12.35v. I then removed that jumper and powered the unit up (again with the PS-ON shorted to ground) and the TV came to life and the menu's...Leave a comment:
-
Re: Insignia NS-50P650A11 - Bad Power Supply?
Hmm, I read that form before posting, but none of the symptoms appeared to match mine. Additionally, no combination of connecting or disconnecting connectors has changed that constant click on and off repeating every 5 seconds other than to disconnect the power supply from the main logic board.
I've tested, in circuit using diode mode on my DMM, every large diode/rectifier and transistor/MOSFET on the power supply and both X&Y sustain units and none show dead shorts. Any other tests that you would recommend to verify...Leave a comment:
-
Insignia NS-50P650A11 - Bad Power Supply?
I am attempting to repair an Insignia NS-50P650A11 50" Plasma TV that will not power on. It exhibits the following behavior: Immediately after applying AC to the power supply, the boards two relays click on and after a brief period, the relays click off and this cycle repeats it self every 5 to 10 seconds indefinitely.
I verified that all voltages (Vs, Va, 3.3v, 5v, 15v) appear to be in spec except the 15v rail, which appears to dip down below 11v before the relays disengage. Currently, the high-voltage connector that provides power to the X&Y Sustain is unplugged as is... -
Re: LG Plasma TV will not turn on - Need Help
This unit appears use the same chassis as a plasma that I was just able to repair: [url]https://www.badcaps.net/forum/showthread.php?t=34861[/url]. Long story short, I had to replace a MOSFET on the power supply board as well as an defective Z-sustain board.
The manual entitled " lg_50pc1dr_troubleshooting_manual.pdf" was VERY helpful. I would recommend that you download a copy of that. That PDF outlines resistance values for each board and their major components. You should quickly be able to determine which board/boards...Last edited by tds-1541; 02-15-2014, 04:43 PM.Leave a comment:
-
Re: LG 50PC3D-UD Power Supply Repair
Well, I was able to get the LG up and running. Turns out the power supply was working just fine after the replacement of that MOSFET. After I replaced that FET, I put the unit back in the chassis and when it failed to power the TV up, I started bench testing it. Turns out you need a load on VS, otherwise the voltage just keeps rising eventual triggering the "protect" circuit. This is not the case for any of the other voltages on this particular power supply apparently. After connecting two 120 volt 50 watt incandescent lamps in series...Last edited by tds-1541; 02-12-2014, 10:58 PM.Leave a comment:
-
Re: LG 50PC3D-UD Power Supply Repair
The secondary side of the voltage regulation circuit operates off of a KIA431A voltage reference IC. I was able to verify it's operation in that it does appear to receive 2.47v between the anode and the reference pin. This appears to be where the "adjustment" happens an it is tied to the VR951 potentiometer. From here I am able to verify that the KIA431A then conducts between the cathode and anode which in turn "enables" the optocoupler. I did try and swap both the KIA431A (for an equivalent AS431) and the optocoupler...Last edited by tds-1541; 02-03-2014, 12:12 AM.Leave a comment:
-
Re: LG 50PC3D-UD Power Supply Repair
I am powering the unit up on my workbench. No other boards attached. The AC-DETECT pin measures a constant 5 volts and does not appear to fluctuate.
I pulled the term "Horizontal Grid Voltage" from that LG service manual entitled: lg_50pc1dr_troubleshooting_manual.pdf
I am able to enable each section of the power supply except for the high voltage section. As soon as I enable the high voltage section, the VS jumps up over 215v and the power supply kicks into protect mode. I just have to figure...Leave a comment:
-
Re: LG 50PC3D-UD Power Supply Repair
I was able to take some high resolution photos of the board. The board is just slightly too large to fit on my old flatbed scanner. The power supply part number is: YPSU-J012B REV 1.0 2300KEG003A-F.
The Motorola MC33067P switch mode controller appears to be controlled by two optocouplers. Following the traces, one appears to "enable" the unit by tying into pin 9 (Enable/UVLO Adjus) while the other appears to tie into pin 10 (fault). The circuit trips into protect so fast (around 1 second), but I'll try and measure the...Leave a comment:
-
LG 50PC3D-UD Power Supply Repair
A friend give me an LG 50PC3D-UD (PDP50X30010) plasma TV for repair. The TV would turn on and the green front panel lamp would blink three times, then the power supply would go into some sort of protect mode and shut down. This happened irrespective of what connectors I had plugged into the supply. I started measuring voltages and all low voltages checked out (5v-Standby, 3.3v, both 5v rails, 6v, 12v, and 19v). In the high voltage section, the HorizontalGrid Voltage (VS) was reading 0v (should be 196v according to the service manual) and the Vertical Grid Voltage (VA) was reading 60v.
... -
[B]About me:[/B] My name is Jake and I am from Wisconsin. I work for an internet service provider and I configure services for fiber business customers. I have several industry specific certifications and spend all day configuring service provider routers that cost more than the average house in my neck of the woods! I love my job.
Electronics in general are a hobby of mine. My grandfather worked for a company that serviced pinball machines, jukeboxes and arcade machines. I believe that it is because of him that I have an affinity for electricity! There are photos of me in diapers... -
Re: New Members - please post your introductions here
Hello all. Long time lurker, first time poster. I made an account because I am in need of help diagnosing an LG Plasma TV power supply.
[B]About me:[/B] My name is Jake and I am from Wisconsin. I work for an internet service provider and I configure services for fiber business customers. I have several industry specific certifications and spend all day configuring service provider routers that cost more than the average house in my neck of the woods! I love my job.
Electronics in general are a hobby...Leave a comment:
No activity results to display
Leave a comment: