I have a magnavox 42mf531d/37 lcd . 4 caps were popped on power supply. It would not do nothing. Replaced the three 1500uf 35v caps and the 2200uf 25v and now it sounds like its coming on but still doesnt light back light. I have 24v at the plugs going to each side of the inverter boards but its like somethings not telling them to come on. I can slightly unplug the left board and the backlights begin to flash but wont stay on its like its jumping the voltage to another pin. What direction now.
-
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Check BLON, DIM on connector. You have 24V and GND wires, then two wires for the BLON and DIM.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. -
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Also check the caps in both inverter boards, all fuses, especially if it has small black fuse with '15' or '20' on the top. Also inspect the IC and the MOSFETs of both boards.
Chassis number of this TV?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
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Alright on powersupply voltage on plugs to backlights
Left backlight right backlight
0v von 0v g
0v vdim 0v g
0v g 0v g
0v g 0v g
0v g 0v g
0v g 24v v
0v g 24v v
24v v 24v v
24v v 24v v
24v v 24v v
24v v
24v vComment
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
OK, it is not getting either BL_ON (Von), or the Dimming signal (Vdim) from the main board.
Time for more pictures of the boards.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
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Here are the pics i did find a smoked place on the cover over the main board it was directly over the black square thing in the bottom middle of picture 5.Attached FilesComment
-
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
So far I cannot find the service manual for this model, we will need that to troubleshoot the main board. Is there chassis number on the model number sticker tag? Something like Model number xxxxx TPE1.0U-LANever 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
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
No additional
information was on tag
just the 42mf number.Comment
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Can we see the tag? Very strange if that is the case.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
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
One other thing, those axial lead Nichicon are not low esr so not suitable for the PSU. Not going to be a problem yet (24V is good) but may be a problem when under load or after the caps have aged.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
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Where is the tag located you want to see.Comment
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
The tag which you state only has the model. It may be in a different encoding.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
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
I have the service data if needed it 's large file I'll be glad to upload or send
also have the panel info just need the information on sticker in set there's about 4 panel versionLast edited by RON_CET; 05-11-2013, 09:39 AM.Ron Driver,BSEE,CET,ISCET,NESDAComment
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Here are pics of back of tv cover, and back of lcd panel with the requested information on them.Attached FilesComment
-
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Here's the service data from your picture for the panel,also attached is a service bulletin,check make sure your serial number falls within the scope of this bulletin,hope this information helpsAttached FilesRon Driver,BSEE,CET,ISCET,NESDAComment
-
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Not that familiar with surface soldering, repalcing these things fix the signal power to the inverter boards.Comment
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
I have just noticed this repair is for a 42mf231d/37 and i have a 531d so this
would not apply to my unit.Comment
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
I have checked diodes on power supply none were shorted except one that was setting the meter off both ways , i took it out of the board and it tested normal i guess its in a parallell or something. Anyway diodes seem to be ok.Comment
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Well, you have 24V, problem is not on PSU...
VON is your problem, so mainboard has to be considered.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
-
Re: Recapped Magnavox 42mf531d/37 still no inverter lights
Well i know that the main board had a couple of smoked spots so i may have to try another board. thanksComment
-
I just got this tv today and it appeared to have no backlight on. After taking off the rear cover and checking again in the dark I can see that MAYBE one quadrant is lit.. But still it's quite dim. I was going to check the LEDs with my tester, and I found LED 1 and LED 2 + pins on the wire from the inverter, but I couldn't identify a ground. Nonetheless I tried using a mounting screw on the inverter board and also the chassis as ground but regardless my tester reads 300 which is what it reads when there is no voltage draw.
I don't know how exactly to test the inverter itself. Is it... -
Hello, I came here after finding some similar questions asked on other monitors and hope someone here can help me get an ancient Viewsonic VP230mp (23" 4:3 LCD) back to working condition.
First a little background, I have a background in computer and electrical engineering, and I'm smart enough to know I know nothing about LCD displays and how they work. For this topic I'm as green as they come.
When the display is turned on the viewsonic logo displays in the uppper left for 2 seconds then the screen goes black, the power LED is green (on) and when a computer is connected... -
I have a tripp-lite aspint 3636vr inverter charger which blow some of mosfet transistors. I replaced them repaired also the driver circuit and tested but the mosfets burn again.
It work very well as inverter and also as charger if I let the rear switch in auto mode (inverter) and charger only(charging) but in auto when I connect the feed line 220V AC first time it pass ok to line and start charging the batteries but when I remove the feed line it pass to inverter mode and if I do it again the second time when passing from charging to inverter the Main transformer start making a...03-06-2023, 07:07 AM -
For some reason I'm just not going to let this 19" TV defeat me. I guess because I have a schematic to work from I feel like I'm oh so close.
History- while adding a turn-on circuit I let a small screw roll under the power board. Worked through all of that circuitry, probably replacing a MOSFET and PWM controller that were not bad but I was following the service manual. Finally figured out that the power supply is in working order when the inverter section (for the backlights) is disconnected. When the +12 supply to the inverter is disconnected the +12 and +5 will come up... -
Hi is any one can help me on getting the Schematics for Magnavox MDR515H/F7 And Magnavox MDR537H/F7 PDF file thank you I really appreciate it. Just need to change some component on
the main board and the power supply board. I looked all over for the internet and I cannot find the Schematics sheet for both of them. I don't know where else to look I hope someone can help me...03-07-2025, 01:03 PM
Comment