Sorry i have to do this in English, but this language is better then my German.
I have 2 defective Revoxen a B710 and a B780
Problem 1:
The B710 has all kind of problems if you touch the processor chip it will start it's own life, spool engines start running, capstan axe is activated etc. etc., this could be the connection to the feed but also the chip itself. Will try to solder it out and change the feed 40 pins but also have to unsolder the piggy back board to get to it. Will keep you informed, but i suspect the processor has an internal failure.
Problem 2:
The B780 seems to have a dead processor, no clock or signals at all (in test mode it has a clock) display gives some chinese on Power on, therefore i suspect this processor Mostek 3872 is really gone. Would like to change it but it's no longer available.
Solution i think: There is a chip called 38P70 this chip has no internal ROM but you can put a 2k( For the Mostek 3870) or 4K (For the Mostek 3872 its the same for the Mostek 36P70) EPROM as piggy back on it's to. If we can program this Eprom (24-28pins) with the original code then we are able to replace this chips.
I am curiuos if someone tried this in the past and if it worked, but how can we get the HEX code listing from STUDER for all types they used this chip?
If nobody has done this sofar, i will try to do it myself in the near future (BUT I NEED THE CODE, SOMEONE MUST HAVE THESE CODES. IF SOMEONE HAS SOME LOVE FOR THE REVOX FORUM AND THERE IS SOME INTEREST TO KEEP THIS STUFF ALIVE FROM STUDER OR REVOX FOREVER PLEASE SUPPLY THIS CODES),
Thanks in advance,
Please reply, any ideas and experience will be very welcome.
Many greetings,
Gert-jan aus die Niederlande
