Alright, just to give a bit of an update. I bought another dead controller from ebay, being sold “as parts”. The owner thought it mostly worked, but the power extension no longer functioned. I don't have power extension on my lift, so I thought I might have a good shot here...
However, I was disappointed once I opened the unit and found the exact same part had exploded on the board, as on my controller!
Once again I could see no part numbers on the dead component.
This must be a common problem with these boards! So I set this aside for a couple of days, ruminated, and then the most awesome thing happened! I took it outside to show someone, and by chance the sunlight reflected off it in a way that I got a small outline of a part number. HOLY COW!!!! Very exciting.
I was able to read “VN31” from the remaining half of the board still intact. After doing some research, this was a part that was previously made by STMicroelectronics. It is a discontinued part these days, but you can still find people that have these chips.
It appears this chip hasn't been made for 10plus years. Now I didn't want to just replace this with the same one as I feared this part might be a ticking time bomb. However, I did a lot of research and came across a component that appears to be better in every way:
The New component is “BTS441RS”, made by Infineon Technologies.
I compared the spec sheets of both the old and the new component, and it has a couple of key things that I think made it way better.
#1 - Protection Circuitry - This new component has an internal protection Diode. My electronics friends think this component is most likely failing due to back driving EMF which might be caused by the contractor when it disengages. The Control board does have some protection Diodes that are supposed to handle this, but after closer inspection they are not the correct type that the Datasheet called for for VN31.
#2 - Efficiency - This part is about half the resistance as the previous component, which means it is more efficient and will produce less heat. This is great since these components are typically attached to a large heat sink. In this case, it is just bolted to the fiberglass motherboard which doesn’t allow for efficient heat removal. Now I understand this component is not being driven to its full potential, so the heat should be small anyways, but still; less heat = good.
#3 - Availability - This part is currently in production which bodes well for it being around for a while. I am just guessing here, but the other manufacturer stopped making these series of chips completely, which leads me to believe there may have been a known issue with this component.
Anyhow, once I have the new chip, I will install it and post another update.
Thanks for following along!
Also, just to add to make this post easier to find, I am talking about the JLG controller 1600286 and the component on the board is labeled as Q31.
