[EPTech]

Hi there,

Since yesterday my Okuma LCS-15 no longer starts. All I did was take out the backup floppies from the rear cabinet to help out a guy that contacted me on this forum. How ironic. The screen displays now gives me a CPU alarm 1-1 bus error. See attached pictures. The address is FCC8 and I have read somewhere on this forum that 0xFCCxxxxx is the TFP board. The least significant 2 bytes of the address are random but the 3rd byte is always C8. The 8 is probably the address of a device on the board itself or in an RAM chip but I do not know which one.
I have had instances where the machine will continue but then a VAC drive error (P-938) is cast. Could something like this be caused by a defect in the fibre cable or transceivers? Or would you say that this may be caused by some intermittent bits in an SRAM on the TFP board?
I basically need some way to rule out the TFP board or the fibres before I order replacement parts.

I must say the machine has been off for at least two weeks but it is in a dry, 17°C environment. I re-seated the boards to rule out a bad contact in the back plane. I also checked the supply with a scope but no problems there.

I checked the fibers with a regular LED light to rule out any real break and the light throughput seems to be consistent over all cables. The light coming from the transceivers seems very faint. When you pull out a transmitting fiber, from a reception socket, are you supposed to see an obvious shiny red dot? All I see is an extremely faint light, but only after complete darkness in the room. And even then you have to look closely. Is this normal?

Any help is greatly appreciated.