Hi there, I'm new to this forum (from USA) but I have two of these units in working condition. One unit I replaced the cracked display with a retrofit LCD I put together that fits inside the original housing. But that's not the reason for my post. What I want to say is on the two switchmode supplies I replaced ALL the electrolytic capacitors. I used my Sencore LC103 and 80% of the original caps were bad or out of spec. I found replacing these caps to be very important for the health of the Boardmaster 4000 -overall. I made sure that I had date codes from this century too,
I used Nichicon capacitors for everything. 105C rating. They datecode their caps and you can request date coded caps made within the last year. 2019/2020. Next I cleaned up the pcb and replaced the two surface mount caps on the Hitachi Inverter INVC158. If you do these simple house keeping things it is going to save you a lot of headaches down the road. Its awesome that there are people out there still using these units. . I Just don't have keyboards for my two units.