BX Instrument Cluster Replacement

[MotoDan]

Hello all,

I have a BX2350 that has a failed LCD tach/hour meter display. A new cluster is over $400 which seems crazy considering I just need the LCD. I am considering reverse engineering the LCD, but need a working display in order to do so.

I can't be the only one with a black LCD. If you have a BX series tractor with a bad LCD display and would be interested in having your panel rebuilt at a reasonable price, please chime in. If there is enough interest then I will move forward with the LCD design.

BR's
MotoDan

 

[B737]

Following this as my tiny LCD works but it wont forever...

I read that this kit will convert our old cluster to the newer style. I believe you have to run a wire to the alternator for RPM and it needs some other power supply run to it, in addition to its harness. My understanding is that its install isnt so cut and dry. ($400)

Kubota #K2771-99000 KIT ADAPTER,CLUS

KIT ADAPTER,CLUS

www.messicks.com

Part # K2771-99000

My next thought was if there were a company in the USA who rebuilds LCDs, sort of like services offered to car enthusiast who repair/rebuild old instrument clusters.

Industrial LCD & CRT Monitor Repair - Commercial Monitor Repair Service | ACS Industrial

Our technicians are experts at repairing industrial monitors. Contact ACS today for a free repair evaluation, backed by a 2-year warranty.

www.acsindustrial.com

sorry not much help here, but interested in the suggestions to come

 

[GreensvilleJay]

'black' LCD sounds like no backlight power, which could be a connector or part failure. I've done a lot of 'reverse engineering' in the past. One 'trick' is to find a part number on the LCD,then 'google' it. You should be able to find the OEM that made it( obviously Kubota didn't..), that'll give you the specs and wiring. If you have the wiring diagram for the tractor , that'll give you a great start in 'reveng' !!

 

[MotoDan]

Following this as my tiny LCD works but it wont forever...

I read that this kit will convert our old cluster to the newer style. I believe you have to run a wire to the alternator for RPM and it needs some other power supply run to it, in addition to its harness. My understanding is that its install isnt so cut and dry. ($400)

Kubota #K2771-99000 KIT ADAPTER,CLUS

KIT ADAPTER,CLUS

www.messicks.com

Part # K2771-99000

My next thought was if there were a company in the USA who rebuilds LCDs, sort of like services offered to car enthusiast who repair/rebuild old instrument clusters.

Industrial LCD & CRT Monitor Repair - Commercial Monitor Repair Service | ACS Industrial

Our technicians are experts at repairing industrial monitors. Contact ACS today for a free repair evaluation, backed by a 2-year warranty.

www.acsindustrial.com

sorry not much help here, but interested in the suggestions to come

'black' LCD sounds like no backlight power, which could be a connector or part failure. I've done a lot of 'reverse engineering' in the past. One 'trick' is to find a part number on the LCD,then 'google' it. You should be able to find the OEM that made it( obviously Kubota didn't..), that'll give you the specs and wiring. If you have the wiring diagram for the tractor , that'll give you a great start in 'reveng' !!

The Black LCD in this case has nothing to do with backlighting. In fact, the LCD for this tractor does not have a backlight.

On being able to repair the LCD, this is not possible. The LCD is a custom part and not available for purchase. The "blackness" comes as the display ages and is not reversible. It only gets darker with time. I suspect the operating temperature range of the :LCD is not adequate for outdoor use.

I design electronics for a living and am quite familiar with custom LCD design, I have already done the preliminary design for a replacement LCD module. I'm just waiting to see if there's enough interest before committing to having a custom display made.

 

[B737]

I totally misread your original post, making more sense now...
If you decide to make a replacement display, count me in to buy one from you. I may be incorrectly assuming the LCD is its own separate part that is wired to the circuit board. But I'm gathering from your post it is an integral part of the entire cluster, which is crazy.

paging my fellow 2350 forum mate @PaulL

 

[Mark_BX25D]

I may be incorrectly assuming the LCD is its own separate part that is wired to the circuit board.

A reasonable assumption, since that's the norm. Not 100%, but pretty close to it.

But I'm gathering from your post it is an integral part of the entire cluster, which is crazy.

Crazy enough that I'd have to see it to believe it. It's hard to see how it would make sense for this application. That approach is a lot more expensive. You need a really big run-rate and some special design requirements for it to make sense.

 

[PaulL]

For me, my LCD works OK. It only provides rev counter and hour meter. I can live without an hour meter if I had to - my maintenance is somewhat haphazard at this age anyway, and mostly driven by elapsed time rather than operating hours, since I don't put a lot of hours on it. A rev counter would probably make more sense to replace with an external rev counter, that'd be easy enough on a petrol engine, but I realise I have no idea how a rev counter works on a diesel - no spark leads to trigger off.

I can't imagine that it's some unique special LCD, it must surely use a standard LCD control mechanism. I guess the question is whether the panel is standalone, or the logic that counts the hours and determines revs is built into the one unit. i.e. is the panel getting a feed of hours and revs, and just needs to display what it's told, or is it getting a feed of whether the engine is running or not (and using a clock and storage to determine hours), and getting a feed of some sort of pulse off the crankshaft (and using an internal clock to turn that into revs).

To be honest, $400 for a new one doesn't sound that bad.

On my current cluster the temperature gauge doesn't work, nor does the fuel gauge. I guess I'm pretty tolerant of things like that not working. If my LCD stopped working, then putting a new cluster in might get me three things starting working.

 

[MotoDan]

Paul,

The good news is that the total time is accumulated in the panel's microcontroller and not the LCD. This means that your tractor will continue to accumulate time - even after the display fails and will magically reappear once the LCD has been replaced.

The micro pretty much runs the show for all of the gauges (stepper motors) and lights and drives the LCD unit directly. The LCD is not technically a "module" since it has no smarts, but is definitely a custom piece of glass made for Kubota. This is not a display that you can source from electronic components distributors, etc. The LCD solders directly to the instrument cluster PC board and can be replaced.

There's a good possibility that your temp and fuel gauges can be repaired as they are driven by small stepper motors - similar to most auto gauges these days.

As for the diesel tach, most are measured by sampling the alternator pulses which correlates directly with engine RPM as long as the pulley ratios are known.

 

[GreensvilleJay]

'black' could also be that the 'contrast' for the LCD module is wrong. Unlike LED displays, LCD units require a square wave signal to turn on/off the segments or pixels of the display. If DC is used ,eventually they will go all black ,looking permanently on.
I'd have to have the dash in my hand to see who made it, when, and what parts are used. For sure Kubota didn't make it, and whoever did more than likely used used 'off the shelf' parts for the LCD display, LCD controller with a custom programmed microcomputer to be the 'brains'. All rather boring stuff to me as I've had 4 decades using micros and LCD for 'proof of concept' for various clients.

 

[Mark_BX25D]

For sure Kubota didn't make it, and whoever did more than likely used used 'off the shelf' parts for the LCD display, LCD controller with a custom programmed microcomputer to be the 'brains

Yep. For Kubota to have this custom made would be a very stupid waste of money on their part. They would have to have a very compelling reason to make this simple device more expensive than it needs to be.

Which means, there is a very high probability of being able to buy an exact replacement. Just look up the part number. No reverse engineering needed. The Internet is a wonderful thing.

 

[lugbolt]

the meter assembly is sold by kubota dealer

the dealer gets it from kubota

kubota gets it from whoever makes it for them

Thus, when you go to order a new hourmeter for your BX, you get whatever kubota sells you. If they ain't got just the hourmeter, you get to buy the whole meter assembly. And yes it's kinda expensive.

kubota ain't the only one who does stuff that way either.

I have a PT35 power tilt unit on my little jon boat. The motor died on the tilt unit. I took it apart, yay, just needs brushes. Easy (and cheap) fix. Call the manufacturer, they don't have any parts to put in it, had to buy the whole actuator for $420. All I needed was $2 worth of brushes, or $20 for the whole brush plate, but no. They (company who builds the PT35) doesn't tell you who they get the actuators from so the customer (me) can't source motor brushes or any other part. It's because they buy them complete from some chinese company more than likely and the chinese company doesn't want to mess with selling any of the parts. Or that chinese company buys the motor parts from a manufacturer in bangledesh or timbuktu or wherever and just assembles it, etc. No telling. Almost all manufacturers do it this way including car/trucks.

 

[MotoDan]

Yep. For Kubota to have this custom made would be a very stupid waste of money on their part. They would have to have a very compelling reason to make this simple device more expensive than it needs to be.

Which means, there is a very high probability of being able to buy an exact replacement. Just look up the part number. No reverse engineering needed. The Internet is a wonderful thing.

All I can say is I wish you luck on finding the LCD display which has the exact pinout, segment drive, etc. The company that makes the complete instrument cluster for Kubota designs these for their various clients and usually per the customer's specifications. The cost to design a custom LCD is nothing when you are selling thousands if instrument clusters.

 

[Mark_BX25D]

It would be something on the order of a miracle if that company makes one special LCD that is ONLY used for Kubota. It's a very simple, generic LCD. There is no benefit to making it a specialized, custom part.

If I wanted to take mine apart I could probably find a replacement in about 15 minutes.

 

[lugbolt]

It would be something on the order of a miracle if that company makes one special LCD that is ONLY used for Kubota. It's a very simple, generic LCD. There is no benefit to making it a specialized, custom part.

If I wanted to take mine apart I could probably find a replacement in about 15 minutes.

Good. Get after it and post up the information so that the rest of us can find a replacement LCD.

 

[Mark_BX25D]

If I wanted to take mine apart

If mine ever dies, I'll do that, instead of making the highly unlikely assumption that it is an uber-custom-made-to-order-never-to-be-duplicated part.

Meanwhile, one of you who has a dead LCD could do that. The only obstacle you might run into is that it might be soldered onto the circuit board. Not a problem if you have the tools and skill to desolder it, but not all do.

 

[GreensvilleJay]

re: All I can say is I wish you luck on finding the LCD display which has the exact pinout, segment drive, etc. The company that makes the complete instrument cluster for Kubota designs these for their various clients and usually per the customer's specifications.

I've 'reverse enginneered' equipment like this for 50+ years, have to admit it's easier now with the Internet and serch engines. Obviously I'd have to have an instrument cluster on my bench to tear apart but it ain't 'rocket science' to me. There's no way Kubota would spec out what LCD pinout for the segment drives,or parts or their placement ONLY that the connector be 'here' and have 'these pins'. They will have a say in the burned program that controls the display based upon whatever sensors(fuel, temp, etc) the tractor series has,as well as temperature specs but NOT the actual chips and parts,let alone PCB layout.

 

[Mark_BX25D]

The company that makes the complete instrument cluster for Kubota designs these for their various clients and usually per the customer's specifications.

*sigh*

No, they don't. They go to a catalog and pick an off-the-shelf display that meets their size requirements and they fit it to their board. That same display will be sold to hundreds of other companies.

They would have to be brain-dead stupid to do otherwise.

 

[B737]

paging @bluedunn how do you like your new instrument panel? how did the swap go? Do you still have your old panel? maybe that could be of some help to MotoDan

 

[GreensvilleJay]

I didn't say that, I was quoting MotoDan, a few posts above...
I'm well aware of how the industry works, was in it for 50 years...though I retired when I turned 40.

 

[UH46CREW]

I don’t know if I’m out of order here but here goes. I have a BX2670-1 with a dead meter panel. I have located the problem but without a real schematic of the PCB or even a photo of a board with all its parts I’m unable to make repairs. I will try to post photos of the problem. It would be great if someone has or could get me a working photo of same area and/or part info of missing part.

any assistance would be greatly appreciated.