Have a Memorex 32" tv will not power on set is dead.have checked large cab in center of power suppy board 158v. Checked con3 power is fluctuateing 5vSB 0 to 6v, 5V o to 1v, 12v 0 to 6v. The board is a Proview Ipos 150 Rev 3.3.I know there are some posts on this but there all over the place would like to start this fresh. Thank you for any help.
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Memorex MLT3221 no power
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Re: Memorex MLT3221 no power
Look real close at all the caps, especially the ones under the heatsink on the right of the board. What you can also do is to unplug the TV, use the hair dryer to heat up the board for 3-4 minutes, then plug the TV in and monitor the 5VSTBY to see if it becomes stable, it sounds like it has bad start-up cap. The bad part is that you have to remove the hest sink to get to them. They are also known for having 2 bad 10uf 450vdc caps for the inverter section.
http://s807.photobucket.com/albums/y...t=DSC04333.jpgNever 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
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Re: Memorex MLT3221 no power
You will need to inspect the caps real close, as suggested, the startup cap for the stby5V which is under the heatsink. Do you have ESR meter?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
Comment
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Re: Memorex MLT3221 no power
They use the Poly caps instead.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
Comment
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Re: Memorex MLT3221 no power
On this model there aren't any known failures with those caps and anyway the TV standby voltage would still be good as they only couple the drive to the inverter transformers.
I see the disc on the main big capacitor (marked 25/105/V46) is bulging, try pressing this down, if you can depress it so it is flat the capacitor is OK, but if you can't then it could be failed.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.
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Re: Memorex MLT3221 no power
The large cap on my board also has domed plastic cap, remove the top, it turns out to be the plastic cap is deformed but the metal cap is flat, you can remove the black disc and see.
It is hard to get to the start up caps since they are mounted under the heat sink. You may be able to fish it through the hestsink hole, you can see it in your pictures. The two caps on my board are lytics type your are Poly type and they are for the inverter circuits, you need to fix the 5CSTBY problem first to see if anything else are bad.
You can also check the DC on that large cap to see if it is fluctuating when the TV is OFF, when TV is on the PFC Voltage booster will kick in, then the voltage will go up to around 380-400vdc.Last edited by budm; 01-09-2013, 12:07 PM.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
Comment
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Re: Memorex MLT3221 no power
At this point it will probably not work since the processor does not have steady standby voltage to run the main board circuits. Need to get the stby fixed first.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
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Re: Memorex MLT3221 no power
https://www.badcaps.net/forum/showthread.php?t=12886
same power board i think maybe worth a read
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Re: Memorex MLT3221 no power
Originally posted by vinceroger69 View Posthttps://www.badcaps.net/forum/showthread.php?t=12886
same power board i think maybe worth a read
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Re: Memorex MLT3221 no power
You have the advantage that you can see what D 10 looks like? Is it like D5 or D7Please upload pictures using attachment function when ask for help on the repair
http://www.badcaps.net/forum/showthread.php?t=39740
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