The Sinclair QL Forum

Suddenly, on a QL of mine, the Mdv1 spins continuously at startup. But only when Trumpcard is inserted. Without Trumpcard or with SGoldcard inserted, the behaviour is normal.
The other QL of mine is not affected by the presence of Trupmpcard, and all seems to work normally.
Any idea please?

Try checking for bent pins in QL expansion port. Try reseating all the chips in the Trump Card.

Thank you Derek for your suggestions. Actually, I had already checked the infamous pins, and also reseated all the Trumpcard chips.
I also checked the continuity of the Mdv1 flat cable.
I'm going to try to change the QL ROM chip

It's (probably!) the mdv1 itself. I replaced it with another microdrive and the infinite spinning disappeared.
For some reason that mdv1 doesn't want to work with the Trumpcard only. I'll run more tests.

Cristian wrote: Thu Feb 13, 2025 9:52 pm It's (probably!) the mdv1 itself. I replaced it with another microdrive and the infinite spinning disappeared.
For some reason that mdv1 doesn't want to work with the Trumpcard only. I'll run more tests.

Spinning but working?
I am very interested about this issue too.

Derek_Stewart wrote: Tue Feb 11, 2025 8:07 pm Try checking for bent pins in QL expansion port. Try reseating all the chips in the Trump Card.

I was always wondering, why sinclair put a male euroconnector on the QL mobo, instead of a female. With a female euroconn, if there was a bented pin issue, it would be on the expansion card and quite easy to fix. Now we need to open the QL to fix the bented pin issue.

I had a microdrive unit that would spin continuously. I came to the conclusion it was the ULA, which are not easily available. But before I could go further, I found another of my microdrive units had developed an open circuit read/write head. So I ended up mading one unit out of two.

Popopo wrote: Fri Feb 21, 2025 10:15 pm Spinning but working?
I am very interested about this issue too.

It's an inexplicable issue to me. That mdv1 unit spins eternally as long as the Trumpcard is installed (only and exclusively the Trumpcard). Other mdv1 units work normally (apparently).

Martin_Head wrote: Sat Feb 22, 2025 10:29 am I had a microdrive unit that would spin continuously. I came to the conclusion it was the ULA, which are not easily available. But before I could go further, I found another of my microdrive units had developed an open circuit read/write head. So I ended up mading one unit out of two.

I suppose your mdv unit spins continuously with or without Trumpcard, other cards etc., am I right?

Cristian wrote: Sat Feb 22, 2025 12:47 pm

Martin_Head wrote: Sat Feb 22, 2025 10:29 am I had a microdrive unit that would spin continuously. I came to the conclusion it was the ULA, which are not easily available. But before I could go further, I found another of my microdrive units had developed an open circuit read/write head. So I ended up mading one unit out of two.

I suppose your mdv unit spins continuously with or without Trumpcard, other cards etc., am I right?

Yes.

As I remember, It was mdv2_, and it started when mdv1_ span up at boot.

I can't quite remember how it works, But it's something along the lines of there being one motor control line, daisy chained through all the mdv ULA's.
And the number of times the line is pulsed determines the mdv that starts.

Have you tried swapping mdv1 and mdv2 to see if that has any effect. Or if you have a floppy disk with a boot program in the trump card, so the system won't try to boot from the microdrive.