# my lcd tv/monitor not powering up



## csy007 (Dec 8, 2010)

right where to start 
i have no idea what make or model this tv/monitor is 
but i know that it wont power up after my brother decided to plug it into caravan 
unknown by me and him the wires in the van was connected the wrong way eg + to - and - to +

then the monitor wont power on 
no red lights or anything 
so me being me who has a fair bit of tech took it apart 
yet to know avail 
i have test the screen and inverter they are fine 
also tested power pack its fine too
there is power going in but nothing to the inverter or power switch 
the main board has this number on it 
BM-2 E213371 
tried everywhere i know to get info but nothing 

at my wits end now because this is ongoing and would like it solved 
i never give up 
so any help would be welcome


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## cwwozniak (Nov 29, 2005)

Is the power pack some kind of AC to DC power supply that feeds low voltage DC to a power input jack on the monitor and was the van battery connection made to that same jack. If so, see if there is a fuse inside of some kind of compartment on the jack or in series some place between the jack and the power switch. If you are lucky the TV power input circuit has some kind of reverse voltage protection that blows an inexpensive fuse instead of burning up some more expensive electronics.


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## csy007 (Dec 8, 2010)

hi the power pack is ac/dc 12v and yes same input jack 
as for the fuses i still searching for them with multitester 
so far as yet no fuse blown and no bad capacitors 
how ever there is one greenish blue component on the board looks like a fuse or resistor all it says is 5a and its 1 cm away from the jack point next to 2 fuses which test fine but this one i cant get any reading from


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## cwwozniak (Nov 29, 2005)

Does the greenish blue component have two leads or terminals? If so and if you can get a meter probe on each of them, see if there is continuity from one lead to the input jack and from the other lead to the power switch? If so it may have been a fuse or some other type of protection device that got blown by the reversed power.

BTW, you don't need to PM me when you add a post in this thread. I have my site preferences to show threads where I have posted and that have new posts in them.


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## csy007 (Dec 8, 2010)

sorry mate lol 
i have removed the component and on it it says 5a on 1 side and the other ru sa i tried testing andgot nothing at all from it 
it does look like a thermal fuse but unsure 
many thanks for the help


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## cwwozniak (Nov 29, 2005)

Would your parts look something like these 3A (3 amp) fuses?

ttp://cgi.ebay.ie/Axial-Lead-Wire-Fuse-PCB-Subminiature-Quickblow-3A-3Amp-/360304236343?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item53e3ce5737


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## csy007 (Dec 8, 2010)

yes mate it does 
thanks very much
you wouldnt believe how much this means 
any ideas if you can replace with some other fuse but of same rating


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## csy007 (Dec 8, 2010)

just another question for you regarding the same lcd 

what would happen if you connected the backlight wires the wrong way ?

i have 4 wires from screen 2 top 2 bottom that insert into the inverter 4 slots 
they are coloured wires blue white pink and black
but unsure which was connect to inverter board cn2 cn3 cn4 cn5


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## csy007 (Dec 8, 2010)

this is my inverter board


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## cwwozniak (Nov 29, 2005)

csy007 said:


> any ideas if you can replace with some other fuse but of same rating


Any 5 amp quick acting fuse with a voltage rating at least a little above the output voltage of the power pack should work. The physical size limit would depend on how much space you have on the printed circuit board when it is inside the monitor housing.

There are are least two possible reasons the fuse may have blown with the reversed power connection. It is possible that the reverse voltage was overloading one or more of the components on the board and the fuse blew before the components had any permanent damage. If you are lucky, replacing the fuse may restore operation.

It is also possible that the reverse voltage caused a catastrophic failure of some other electronic components and the failed parts then drew much more current and blew the fuse. The fuse protected the power pack and other components from more serious damage and a possible fire. In this case a replacement fuse may blow as soon as you apply external power or turn on the power switch.



csy007 said:


> what would happen if you connected the backlight wires the wrong way ?
> i have 4 wires from screen 2 top 2 bottom that insert into the inverter 4 slots
> they are coloured wires blue white pink and black
> but unsure which was connect to inverter board cn2 cn3 cn4 cn5


If there are four wires and not four pairs of wires, it sounds like the LCD panel has two CCFL tubes for the backlight.



csy007 said:


> this is my inverter board


There was no picture visible in your post but when I quoted it for this post, a possibly corrupted URL appeared as an image link. I think I was able to edit the URL to get a valid picture. Is the inverter that was built into the monitor the one pictured in the attachment? The one in my attached picture looks like it was designed to handle four CCFL tubes, not two

If your backlight cables consist of four pairs of wires with plugs that match the sockets along the upper left and right edges of the inverter in the photo, it should not matter which plug goes into which socket. If there are only four individual backlight wires, then I am not sure how they would connect to the inverter.


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## csy007 (Dec 8, 2010)

YES thats the inverter 
sorry about link not working and inaccurate details 
there is 4 wires from top and 4 from bottom of the screen 
i thank you very much for all your help


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## cwwozniak (Nov 29, 2005)

You're welcome. Please let us know if a new fuse fixes the problem.


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## csy007 (Dec 8, 2010)

hiya i have replaced the 5a pico fuse and then i got the white screen 
so i trace my step backwards and yes u guess it those inverter wires wrongly placed
pink and white to the top left and the other one blue black to bottom left 
and yes went put properly in the lcd tv / monitor working perfectly 
so thank you again 
your help is brill 

lmao what you know about washing machines lol 

many thanks mate


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## cwwozniak (Nov 29, 2005)

You are most welcome.



csy007 said:


> what you know about washing machines lol


Put clothes and detergent in top
Close Lid
Select water temperature 
Turn knob to start position and push in
Open lid when done and transfer wet clean clothes to dryer

That's about all I know. When I was going to school years ago and using a laundromat it was ...

Put clothes and detergent in top
Close Lid
Select water temperature 
Insert coins in slider and push in
Go to pub next door for a pint or two
Come back from pub and ignore dirty looks from people waiting for an empty machine
Open lid and transfer wet clean clothes to dryer


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## csy007 (Dec 8, 2010)

lmao 

well done 
no on a serious note i have dyson cr01 machine with code f11 on it 
turns out to be a fuse onboard but just replacing the fuse is not enough as it wont let the outer door lock lock 
tried replacing lock but no good and also i found out that the rectifier may have gone but i have no idea what this is ?
searching the net its this thats shorted and im wondering if there is a way to test them


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## cwwozniak (Nov 29, 2005)

Might be time to start a new thread for this new problem.

A rectifier is a device that can be used in a circuit to convert AC power to DC. A single rectifier is a two lead part (typically a silicon diode) that only allows electricity to flow in one direction. Sometimes four diodes are connected together in a single four lead device that has two AC input lines and a positive and negative set of outputs.

An ohm meter that applies at least 1 volt or so to the test probes can be used to do a quick check of rectifiers.


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## csy007 (Dec 8, 2010)

Thanks will start new thread


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