MXR dead this morning... (and now alive!)


Philip

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Philip, did you disconnect the charger cable without turning the kill switch to the off position?
Sort-of. I hadn't touched the kill switch ever before, I didn't see the need do. But on the morning when the bike was almost fully charged, I turned off the power switch on the yellow GCFI unit first. This is the only thing that I remember doing differently than before.
 

ababaoka

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Hey Guys, I may have a lead for new BCU's. I used to work for an electronics manufacturer and we made many of the PCBs for Alta. Thinking about the total number of bikes made vs number of boards we made we might have been one of the only suppliers. This being said i may know someone who has "blueprints" including BOM for many of the Alta PCBs.

I am going to reach out to my contacts to see if i can get these as my 2019 EXR is giving me the same problem, no power when key switches. Mine was left plugged in (started charging around 40%) expected to go riding on a 100% battery and nothing. I dont know if my power went out or what but i really need a beer. Very expensive paper weight in the garage atm.
 

Oded

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That will be a great help.
These BCUs are failing, and finding a replacement is not easy.
Please see uf you can also find blueprints for the A packs (EX. MX. SM).
 

Bionicman

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WA
Hey Guys, I may have a lead for new BCU's. I used to work for an electronics manufacturer and we made many of the PCBs for Alta. Thinking about the total number of bikes made vs number of boards we made we might have been one of the only suppliers. This being said i may know someone who has "blueprints" including BOM for many of the Alta PCBs.

I am going to reach out to my contacts to see if i can get these as my 2019 EXR is giving me the same problem, no power when key switches. Mine was left plugged in (started charging around 40%) expected to go riding on a 100% battery and nothing. I dont know if my power went out or what but i really need a beer. Very expensive paper weight in the garage atm.

Very disappointing- I too am concerned about this paperweight scenario

Good luck getting positive results & yes if you can get that information- thank you!
 

Bionicman

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Yikes....I wonder if a power out during charging will cause the same issue?!?!?! LETS ALL START USING THE KILL SWITCH FROM NOW ON!!!!!!!

Yes I would highly stress using the kill switch for any thing that requires rider input on the bike !! I don’t start my bike plug in/out charger without first starting with run switch in off position
 

ababaoka

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Update: I did a series of checks suggested from @Rashid510 and other threads

Checked Key Ignition ON/OFF
Any sign of lights or noise when switching key
Unplugged Battery Connections
Tried standard and rapid chargers on different outlets
Light taps with rubber mallet in case of contactor stuck

Nothing seems to have changed. Seeming more and more like the BCU. I'm going to be tinkering around with @Rashid510 in a couple of weeks in SF, anyone with an R-pack in the area want to join and willing to use your battery for checks?

Lastly regarding information to assemblies. Rocket was a producer of the A pack for sure but not certain on R packs. I'm going to reach out to the owner of Rocket, we used to ride often together, and sit down with him to see what exactly is there and if he would be open running more boards if we pay for materials. This makes sense as they already have tooling. Any notes on ownership of these designs? I'm sure he will be concerned about liability. Just thinking long term as Liquid Performance still has parts.
 

Mark911

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Corona Ca
The whole "12v power on" system starts with the 9v battery and the key switch. It simply sends 9v to the BCU which directs it several ways. One circuits goes to the controller chip, one to the a timer, and another to a photovoltaic isolator which controls the main 12v DCDC down converter (takes 300v and generates a regulated 12v supply to feed 95% of the bike!). Note, there's various voltage regs involved as well which convert the 9v into voltage(s) compatible with the particular chip in question.

If the wiring of or any of the components in these circuits is bad NO 12v and NO GO. In addition, the key switch timer "times out" (just a few seconds) to save the 9v battery and if it "times out" before the DCDC converter fires ups it'll shut down the 9v input to everything else, again, NO GO.

My experience is that weird high voltage isolation issues can occur which either directly or indirectly (via a whole list of possibly overstressed components) cause the DCDC converter to fail as the 12v stage is sensitive to these voltages. Something, possibly charging, possibly hooking up with the RUN switch ON (the RUN switch is part of the HVIL system (High Voltage Interlock Loop) pushes the DCDC or another stressed part that in turn pushes the DCDC into failure mode.

Most of the BCUs with issues that I've seen have had bad DCDC converters (at least). They're not cheap (about $250 new), but there's usually some on ebay for less, you just need to know what specs (and the corresponding PN) you can afford to deviate from OEM with. For example, I don't think my bike will ever see the low temp that Alta speced for the DCDC so I can live with one with a higher low temp limit. Same for things like lead used or not used in the terminals, I don't care. The 350v mini seems to produce 12v just fine within the pack voltage range so if I can't find a 300v . . . . . . . . . etc. Problem is, unless you find the actual cause and fix it the issue will no doubt happen again.

Now, getting that sucker out of the PCB (and the PCB out of the cover for that matter) is a real PITA, particularly with the A packs, but it can be done with typical hand tools and a good strong soldering iron (and good low temp melting solder).
 

ababaoka

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Fremont, CA
So i should be able to verify 9V going into BCU. I did get a 9v low voltage when i first received the bike but after a good charging never saw it again. Where would i measure downstream from BCU to verify which DCDC down converter is not functioning?

I had to retrain myself to use the killswitch because with my BMW F800R the killswitch had a bad flex cable which would wear and not work if used too many times. I retrained myself to use it again for the Alta and now find myself using it on my gas bikes instead of just ignition key. Granted I am sure there was a time or two that due to laziness after a long ride didnt take note of killswitch position.

Coming from EMS industry and having a roommate who still works in EMS I would have no problem reworking the board given I know what part to replace.

Going back to legality of pcba design ownership, was it bought up or no mans land?
 

Rashid510

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Update: I did a series of checks suggested from @Rashid510 and other threads

Checked Key Ignition ON/OFF
Any sign of lights or noise when switching key
Unplugged Battery Connections
Tried standard and rapid chargers on different outlets
Light taps with rubber mallet in case of contactor stuck

Nothing seems to have changed. Seeming more and more like the BCU. I'm going to be tinkering around with @Rashid510 in a couple of weeks in SF, anyone with an R-pack in the area want to join and willing to use your battery for checks?

Lastly regarding information to assemblies. Rocket was a producer of the A pack for sure but not certain on R packs. I'm going to reach out to the owner of Rocket, we used to ride often together, and sit down with him to see what exactly is there and if he would be open running more boards if we pay for materials. This makes sense as they already have tooling. Any notes on ownership of these designs? I'm sure he will be concerned about liability. Just thinking long term as Liquid Performance still has parts.

If you can get a connect with the owner of Rocket, that will be funny as he has made quite a few comments about Alta in the past. Boards should not be the issue, its putting them together to create topcovers (as a member once said, hard to part with). Bummer the easy stuff did not work. Now for the fun stuff.
 

Mark911

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Location
Corona Ca
So i should be able to verify 9V going into BCU. I did get a 9v low voltage when i first received the bike but after a good charging never saw it again. Where would i measure downstream from BCU to verify which DCDC down converter is not functioning?

I had to retrain myself to use the killswitch because with my BMW F800R the killswitch had a bad flex cable which would wear and not work if used too many times. I retrained myself to use it again for the Alta and now find myself using it on my gas bikes instead of just ignition key. Granted I am sure there was a time or two that due to laziness after a long ride didnt take note of killswitch position.

Coming from EMS industry and having a roommate who still works in EMS I would have no problem reworking the board given I know what part to replace.

Going back to legality of pcba design ownership, was it bought up or no mans land?

The 9v system doesn't charge, it's just a high quality 9v Lithium battery from the Energizer Bunny, similar to what you might find in a good household fire alarm. You'll find it under a little access cover inside the ACM. I'm sure there's a link somewhere in the AOF showing how to replace it. The circuit goes from the ACM (the module under the seat with all the wires) and travels down the LOW VOLTAGE harness to the battery. It's a pretty short trip! This pigtail doesn't have many wires and on my MX it's the PURPLE wire. I'm pretty sure your bike is the same.
 

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