The Sinclair QL Forum

I am testing a QL here with an issue 7 motherboard.

I am having problems with mdv1_ - I have tried 3 units and none of them will format a good (repaired) cartridge which formats fine in mdv2_

All 3 units have been very good at reading cartridges, and I have used a new roller.

The odd thing I have noticed is the extra resistors on the 8302 - I have a feeling that these are not required on the issue 7 motherboard - can anyone confirm (as the service manual only covers up to issue 6).

Anything else I could try?

Rich,
what exactly is the symptom of "doesn't format"? Does format and doesn't work, or returns with format failed?

You know that "Format failed" could also actually mean "write protected" - There's a bug in most ROMs that messes up the error message in this case.

Even if it sounds weird: If all else fails, I would (because most of the circuitry is shared between drives and obviously isn't broken) try replacing mdv2_ - Could easily be it doesn't correctly de-select and thus disturbs an otherwise working mdv1_.

Tobias

In which case just disconnecting mdv2_ would restore mdv1_ to function, wouldn't it?

So was the proposal, yes

RWAP wrote:I am testing a QL here with an issue 7 motherboard.

The odd thing I have noticed is the extra resistors on the 8302 - I have a feeling that these are not required on the issue 7 motherboard - can anyone confirm (as the service manual only covers up to issue 6).

My QL has issue7 board and the extra resistor are not present!