thanks for reply.
strange coincidence: about a week before I got the 2230, I bought a digital scope (Hanmatek DOS1102, same as OWON) during an action at Ama***n, at almost half the normal price. I could not resist that bargain!
My purpose for it is to be able to see fast and slow things like I2C communication.
My workhorse is a 20MHz Hameg HM205 or so, but unsuited for that.
Now for the 2230:
I have removed the GPIB option (+memory) to take a look fot loose connectors hidden behind the mounting plate and under de CRT.
Without this option, the scope looks to be working analog only, do you need to jumper some cables?
Anyhow, I found nothing suspicious.
Also, I tried the Kernel isolation, and looking at the pins of U9112 and U9114.
All looks similar as in the service manual, except for pins 16/17/18/19 of U9114. There is a nice pulsetrain, but not as displayed on figure 6-3.
It looks they are all the same, but no pins are shorted.
A thing I have never came across before: Have you ever experienced bad EPROMS? Ans if so, where could I find hexdumps?
best greetings, Harry