New Eagle digital indicator

[2PAC Mafia]

Hi,

I´m trying to repair a few of these digital indicators. They are from New Eagle (ASM-Gage-002-00). The problem is they are not showing anything.

As a main components I have:


L9616D --- CAN communication IC

24C02WP --- Memory

SMD code: NY9Q = TC1185-1.8VRX (Voltage regulator)

5333 SMD (5 pin SOT)= Not sure about that, I thought it was LED driver for back light but it´s not matching in configuration as it should be.

LPC2119FBD64 --- IC microprocessor

KD8 = AZ23C5V1 (OK)

M393 = Comparator. (Tested of circuit)

I have tested the power supply inside, I have 5V, 3,3V and 1,8V.

I have tested the reset at pin 57 of microprocessor and I have 3,57V and oscillator running.

The LED´s for back light are not switching on, I forced them just to see if that was the problem but the LCD is not showing any information.

Now my question is, I´m thinking if the unit needs some kind of external communication signal through the L9616D to start up.
I also would like to know if is possible to test the LCD itself. It has a flat cable from board to LCD.
I´m thinking in these two options, LCD broken or L9616D broken as I don´t see other fault as much as I can check.

It seem it has a common failure as the company who works with this brand told me and they seem to be obsolete. They are installed at yachts to monitor Seakeeper system. Some pictures:

http://www.restoretronic.com/descargas/New Eagle Vista placa.jpg

http://www.restoretronic.com/descargas/New Eagle Vista LCD.jpg

 

[dr pepper]

I'dve done just what you have.
The only other thing is if you have a logic probe, probe around the pins of the ic and see if anythings going on other than the osc, might also be worth poking around the connector and cycling the power to see if theres any comms at fire up, at this moment you dont know if the unit is faulty or its powering up and refusing to display anything, might even just be a setup thing.

There are diffo types of lcd, but generally the backplane is driven with a squarewave, and the segments not lit are driven with the same squarewave, when the wave to the segments are out of phase with the backplane the segment lights (I think I got that the right way round).
You can get lcd to show segments with an electrotstatic field, but thats not going to check the connector strip, the little rubber liquorice allsort doofer that connects the lcd to the board is a possible cause of the fault, might be worth cleaning, allthough from the pic it looks like theres a flexible pcbtaking the signals to the display.

 

[2PAC Mafia]

Hi dr pepper,

I'dve done just what you have.
The only other thing is if you have a logic probe, probe around the pins of the ic and see if anythings going on other than the osc, might also be worth poking around the connector and cycling the power to see if theres any comms at fire up, at this moment you dont know if the unit is faulty or its powering up and refusing to display anything, might even just be a setup thing.

There are diffo types of lcd, but generally the backplane is driven with a squarewave, and the segments not lit are driven with the same squarewave, when the wave to the segments are out of phase with the backplane the segment lights (I think I got that the right way round).
You can get lcd to show segments with an electrotstatic field, but thats not going to check the connector strip, the little rubber liquorice allsort doofer that connects the lcd to the board is a possible cause of the fault, might be worth cleaning, allthough from the pic it looks like theres a flexible pcbtaking the signals to the display.

What do you mean with logic probe around pins? Just to see if the IC is communicating or we have some kind of signal apart of oscillator? I have scope to check them.

By your experience, do you think it should show anything only with power or should it receive some external communication signal to start running?

May be if I measure these squarewave signals for backplane and segments at processor means that LCD is the problem.

This LCD is working with a flexible flat communication cable, there is not elastomeric.

 

[dr pepper]

Yes just probe around and see if theres any digital activity, nothing specific, your 'scope will suffice just as well as a 'probe, I find a probe being smaller easier to deal with and if you have/get one with tones you dont need to take your eyes off the pin being checked and risk shorting something.

I have some experience of aircrfaft instruments, if something is wrong or theres no comms the display usually shows something, though this is marine not aviation.

Yes thats a good idea, check to see if the lcd is driven by hardware, if so the pins to it will go to a driver ic, if not maybe the processor has a built in lcd driver, its unlikely the lcd will be totally driven by software, you should at least get the backplane squarewave, if you get plenty of squarewaves and some are out of phase with others then the unit is trying to display something.
Older lcd's 'wear' with sunlight, they fade, it unlikey this has faded to the point where you cant see it, has the unit been messed with?, there is a polarizing plate on the lcd that if removed or put back wrong you wont see anything, look at the lcd through a pair of polarized sunglasses (not a joke, when I was at school I modded a cheap digi watch so you could only see the digits through sunglasses).

Cant remember where or what but I sort of recall some lcd manufacturer having probelms with the adhesive used to bond the flexible pcb to the display, it reacted with the tracks on the glass and erroded them away, if this is the case then looks like its dead, you might be able to see it with a mini microscope.

 

[2PAC Mafia]

Hi,

Yes just probe around and see if theres any digital activity, nothing specific, your 'scope will suffice just as well as a 'probe, I find a probe being smaller easier to deal with and if you have/get one with tones you dont need to take your eyes off the pin being checked and risk shorting something.

I have some experience of aircrfaft instruments, if something is wrong or theres no comms the display usually shows something, though this is marine not aviation.

Yes thats a good idea, check to see if the lcd is driven by hardware, if so the pins to it will go to a driver ic, if not maybe the processor has a built in lcd driver, its unlikely the lcd will be totally driven by software, you should at least get the backplane squarewave, if you get plenty of squarewaves and some are out of phase with others then the unit is trying to display something.
Older lcd's 'wear' with sunlight, they fade, it unlikey this has faded to the point where you cant see it, has the unit been messed with?, there is a polarizing plate on the lcd that if removed or put back wrong you wont see anything, look at the lcd through a pair of polarized sunglasses (not a joke, when I was at school I modded a cheap digi watch so you could only see the digits through sunglasses).

Cant remember where or what but I sort of recall some lcd manufacturer having probelms with the adhesive used to bond the flexible pcb to the display, it reacted with the tracks on the glass and erroded them away, if this is the case then looks like its dead, you might be able to see it with a mini microscope.

There are not digital signals, the only oscillating signal is cristal, I´ve checked all the processor pins, mainly I have 5V, 3,3V, 2,5V, 1,8V... but not typical communication signals.

There is not driver IC, it seems the processor is in charge of LCD. The unit was working at the boat and failed for some reason, it´s sun readable but they are not installed at sunny place directly usually.

I have checked at CAN bus IC just when we switch on if we have some signal at TX but nothing.

With this behavieur now I would say the processor is like hanging or damaged partially.

 

[dr pepper]

Agreed, is the rom ic part of the processor?, maybe the rom is corrupted, or the checksum doesnt add up and the chip just sits there.
The only other thing you could look for then is a reset i/p to the processor, its probably internal but possibly theres a r/c or a timer ic/supervisor chip in control of it.

 

[2PAC Mafia]

Hi dr pepper,

it has internal flash memory. Externally it has eeprom 24C02.

The reset pin 57 at processor goes to a J56C (SMD code) SOT23. It´s connected to 3,3V, ground and reset output, which is in 3,3V. This means it´s some kind of voltage supervisor and send high level or low level to processor (reset active at low level). This pin 57 also goes to LCD connector.

The processor has also I2C bus to drive an LCD or similar.

Finally I leave it as I don´t think I can do anything else to repair it. Thanks for your help.

 

[dr pepper]

Yes maybe your right, theres only so much you can do.

Is there much work out there for this kind of thing, allways something I fancied. I have a welding certificate and all the gear too, I know someone who went doing fabrication work on yachts, not seen him for a while I think he's doing well.

 

[2PAC Mafia]

Do you mean if there is work for yacht building and repair?

 

[dr pepper]

Yes.
Theres a couple of people at a local marina that travel and do repairs and building for people, sounds like an interesting way to earn a living.

 

[2PAC Mafia]

Yes, marine market here in my island is very important, as we are located in the middle of Mediterranean sea there are a lot of yacht ports so is plenty of maintenance marine companies. Year after year marine industry is grewing.

I only work on electronics for marine and industrial.

 

[dr pepper]

Good to hear, I have that as an option then.
Scotland part of the UK has an important marine culture too, there are lots of islands, however they are very remote.