Hellwin stage 100 midi 5 buttons footswitch problem

[MassHysteria]

Amplifier is working. I can change channels from the amp front panel switches. The problem is the 5 buttons midi footswitch. Tried using TS and TRS cables with no difference.


Symptoms>>>
Powering on the amp >>>>>>> midi footswitch led lights will flash sequentially (initialization). After that, all the lights on the footswitch will be off and amp will not respond to footswitch (amp will respond to the front panel switches).

initial troubleshooting>>>
Disassemble the footswitch to see any loose connection. Good connections on the jack, no apparent defects on the PCB, and switches are OK.

Any insight would be greatly appreciated.

 

[MassHysteria]

UPDATE>>> somehow the internal processor for the footswitch got corrupted. I suspect the electrical ESD generated during connecting/disconnecting. It is important to connect the footswitch first and then power on the amp. Making sure the footswitch cable is unpowered before the connection. Otherwise, fluctuation of power in footswitch cable during plugging on/off will toast the onboard chip from the footswitch.

The components in my footswitch are still good but the programming got corrupted. So my footswitch is bricked at this point. It needs reprogramming. I will check with the manufacturer about reprogramming it (if they even offer the service). These footswitches are discontinued so i will have to hunt for another one in the wild. wish me luck.

The footswitch itself use SiliconLabs C8051F314 processor for switching functions. The programming is hard-coded into the processor so I will not be able to just swap a new chip. It will not function as intended without correct programming. It use serial communication to communicate with another C8051chip inside the amp via TS cable.

Attached file is the spec for the C8051 chip

 

[MassHysteria]

Workaround>>> The amp accepts TS footswitch cable and 5 pins MIDI. Since my original footswitch is bricked, i like to use the MIDI signal from Boss GT8 (or any other midi switching device) to switch amp channels. Now i can use GT8 to change amp channels and use onboard GT8 effects with it.

This is the optocoupler for the MIDI function. I swapped mine out with a fresh new one. These optocouplers have LED inside, and will burned out over time (disabling footswitch AND MIDI functions). with this i can use MIDI plug to change channels from the amp. Using 5 pins MIDI cable, (GT8 MIDI out to Hellwin MIDI in). Step on GT8 footswitch (GT8 automatically send out MIDI signal to the amp), save the setting on the amp using "MIDI learn" button. The amp will go to the saved setting when i step on the same GT8 footpedal.

Loud amp with killer feedback
Thank you Ed Seith and Eric Kane for providing me with schematic. It helps a lot making sense of the modern day circuitry.

 

[MassHysteria]

Guitar input jacks are getting wonky from plugging in/out constantly so i swapped them out with new ones.