Replacing backlight with LEDs in Raymarine E-Series E120 display

[PhilMay]

I could not find a good description of this process, so I have written one to help anyone else who wants to fix their display.

See http://blog.mailasail.com/anastasia/489

 

[petem]

Nice write up!

 

[andy59]

Thanks for that , i have one in the garage that needs doing .

 

[Assassin]

You don't need 24 volt LED's as they are all the same LED and they only vary in the resistor which is fitted, perhaps looking at this and better understanding it a little more thoroughly would see you have several options which you could give to others, this can also be transferred to other forms of lighting and make an above average write up a superb write up.

 

[jrudge]

This seems an unpleasant and critcal reply given the op posted something that over time may prove useful to many

Whilst the led underlying it maybe the same the product sold is 12v and 24v which the op pointed out needs to match the power supply of the unit.

If you have a solution to making the unit operate over a wide voltage range then why not post specifics ?

 

[petem]

This seems an unpleasant and critcal reply given the op posted something that over time may prove useful to many

Whilst the led underlying it maybe the same the product sold is 12v and 24v which the op pointed out needs to match the power supply of the unit.

If you have a solution to making the unit operate over a wide voltage range then why not post specifics ?

I agree, an ungracious / rude response. It takes time to write these things up and share them and that's to be encouraged.

 

[Andrew M]

This seems an unpleasant and critcal reply given the op posted something that over time may prove useful to many

Fully agree.

Thank you to the OP for putting this up, I've had to have one of our 4 MFDs repaired for this very fault and believe that Raymarine may, may, be pulling out of that service as parts become obsolete, this could be a very timely and useful DIY. Much appreciated.

 

[Switch]

I agree, an ungracious / rude response. It takes time to write these things up and share them and that's to be encouraged.

+ 1 Thanks for posting petem, I wish I'd seen this a few months ago when my back lighting went 'kaput' on my E120. Ended up paying Raymarine a few hundred quid to fix it.

 

[PhilMay]

You don't need 24 volt LED's as they are all the same LED and they only vary in the resistor which is fitted, perhaps looking at this and better understanding it a little more thoroughly would see you have several options which you could give to others, this can also be transferred to other forms of lighting and make an above average write up a superb write up.

I think you meant to say the 12V and 24V strips just vary in the number of LEDs wired up in series? The 12V strips have three 5050 in series and the 24V have six in series between the cut points.

So yes, you could cut up the 12V strip into the groups of three and wire those in series to get groups of six, but it would a mass of wiring that you get for free if you buy the 24V strips. If you took a short cut and series wired a pair of 12V strips containing multiple groups of LEDs then
- you would have to ensure there were the same number of LED groups in each strip to balance the voltage equally across each strip
- the failure of a LED group would unbalance the voltage split and eventually lead to failure of both strips.

Personally I have a 24V supply but rather than use 24V strip I chose to go with 12V strip and power the display from an external 5A Buck converter. My original plan was to put a little MP1584EN converter inside the display so it could still run off either 12V or 24V, but the converter was getting too hot at max brightness and going into thermal shutdown. Adding a heat sink would probably have solved the problem, but in the end I chose to minimize the number of components sealed inside the display casing that might cause problems.

Always best to keep it simple.

 

[kashurst]

well done finding the PWM output on the circuit. Did you have a diagram or just poked about with a 'scope until you got lucky/intelligent guess?

 

[jimmy_the_builder]

I'm waiting for jfm to jump on this thread with instructions on how to make the leds colour-change

 

[vas]

I'm waiting for jfm to jump on this thread with instructions on how to make the leds colour-change

.. and link to a fusion soundsystem, don't forget that

V.

PS. to the OP, welcome to the forum and very well done with the writeup!

 

[PhilMay]

well done finding the PWM output on the circuit. Did you have a diagram or just poked about with a 'scope until you got lucky/intelligent guess?

Actually the point I chose is just the input to the high voltage transformers, so pretty much the first place I tried. I spent a long time trying to eliminate the glitch in the dimming, but it looked to me like the PWM is generated by the PIC microprocessor, based on a protocol exchange with the main processor. (That is just a guess based on what looks like a flurry of messages going into the PIC when you dial the dimmer knob.)

There is another PWM signal used to dim the keyboard LEDs, and that one does not glitch. I looked at using it to control the LEDs, but it does not have a common ground with the display power source so I would have had to introduce an optical isolator in order to decouple the signal. Also the keyboard LEDs turn off at full brightness, so it would have needed some more electronics to prevent that.

 

[MrB]

Actually the point I chose is just the input to the high voltage transformers, so pretty much the first place I tried. I spent a long time trying to eliminate the glitch in the dimming, but it looked to me like the PWM is generated by the PIC microprocessor, based on a protocol exchange with the main processor. (That is just a guess based on what looks like a flurry of messages going into the PIC when you dial the dimmer knob.)

There is another PWM signal used to dim the keyboard LEDs, and that one does not glitch. I looked at using it to control the LEDs, but it does not have a common ground with the display power source so I would have had to introduce an optical isolator in order to decouple the signal. Also the keyboard LEDs turn off at full brightness, so it would have needed some more electronics to prevent that.

Gone over my head but a bloody good tutorial. PLEASE stick around and post more invaluable advice, people like you make this forum great.:encouragement:

 

[Assassin]

Hardly rude or ungracious, merely constructive.

The OP had an excellent opportunity to expand on this article and apply it to so many things ranging from backlighting to various marine lighting applications and in my opinion it could have led to the encouragement of other people to produce their own LED items for various parts of their boat which I would wholeheartedly encourage.

 

[JerryC]

Many thanks PhilMay for an excellent first post! Welcome to the forum and please just ignore the banter and criticism, there are a few big egos on here, but most of us ordinary mortals really value helpful and informative posts like yours.

 

[BlancoJr]

I could not find a good description of this process, so I have written one to help anyone else who wants to fix their display.

See http://blog.mailasail.com/anastasia/489

Hi, and thank you for sharing this excellent guide!

It actually encouraged me to purchase an e120 (+radar) with broken backlight. I ordered the parts from Ebay (approx 30 USD), and dove in.
2 hours later i pressed the power switch and it worked, and I now have a complete nav setup and only had to part with 570 USD :encouragement:

The only "trouble" I had was that I got a LED strip with silicone cover, so i had to remove the silicone on both ends of each strip to expose the connectors. But well worth the effort.

 

[Elessar]

I'm waiting for jfm to jump on this thread with instructions on how to make the leds colour-change

no - it's raymarine he'd just test to see if it floats.

 

[starfire]

Good work!
I spent ages replacing all the semiconductors around the display backlight power supply, only to find one of the (unavailable!) Transformers had gone. The mfd was robbed for spares instead.
I did have a partial circuit diagram somewhere. Part of the circuit monitored the display current & could still be useful.

Cheers

 

[Kcman]

I read your procedure for replacing e120 backlights.
Question. Did you ad a heat sink for the mosfet? If so, what did you mount it to?
Thanks