Recent content by GrahamN

I have an A1200 here that won't boot. When trying with DiagROM I get a message on the serial port that says: Parallel Code $ff - Start of ROM, CPU Seems somewhat al and that's as far as it gets. There is no video output at all. I get the same message with an accelerator card fitted. I've...

Yes - I get a signal that looks OK (from the chip), but I don't currently have a working Amiga here to compare it with. I am starting to wonder if I have a faulty CXA2075 - I only have the one at the moment, but I've ordered some more, so may try replacing it when they arrive.

Yes - but even a capacitor only from the composite video out pin should surely show something on the monitor?

I even tried temporily soldering a lead directly to pin 20 of the CXA2075. I tried the originally specified 470uF electrolytic (Panasonic - of the same type I've used on dozens of recapping A600 / A1200 boards without issues). I also tried a basic 100uF electrolytic capacitor that I've used...

Thanks for your thoughts. The signal comes from the -ve pin of the capacitor through a 75 ohm resistor to the socket. The path to the socket and the socket itself was checked and is good. To be absolutely sure I removed the capacitor, connected the +ve lead of the capacitor only to the board...

I've spent the last hour or so scratching my head with this A1200 problem as it isn't the usual composite video problem with a dodgy delay line. I have an A1200 board that works fine on RGB, but not on composite. I initially diagnosed a faulty delay line (checked by shorting pins 16 & 18 on the...