The Sinclair QL Forum

Thanks again for the replies.

So I managed to get an hour this morning on the QL.
The fault hasn't come back and with regards the ribbon cables I have lifted the board and drives back out and checked for continuity and they all seem good.
I am worried at this point that just as with the constant ...

Thanks again for the reply.

So this morning I finally had time to look again at the QL.
My first task was to measure 'a' in the post above.
Fired it up still out of the case, measured pin 10 on the mdv2 socket, 0 volts on pin 10.
Switched it off, plugged in both microdrives and mdv2 is not spinning ...

Hi James!

I've been thinking about your 'leaky' MDV 2 and taking another look at the schematic, I'm wondering about the possibility of leakage from the MDRW line that - on QL MDVs - is connected via D23 (and D22 for MDV 1) though the WP switch in a 'clever' arrangement to enforce write-protection ...

I tested them both in and out of circuit with a multimeter and also out of circuit with one of these chinese component tester jobbies.
I replaced tr4 and tr5 anyway but had no ZTX551's for tr7 and tr6.
I swapped 7 and 6 over but that made no difference.
I have been this morning to the local ...

So TR7 and TR5 are fine. D17 is fine.
I am getting between 3 and 4 volts on pin 10 of the MDV2 connector all the time, 0v on pin 10 of the MDV1 connector as it should be.
Looking at the schematic and with my limited knowledge I can't see much else that it could be as the circuits that power each ...

Yes the ribbon is fine and the problem manifests on either drive when plugged into the second slot, even with just that drive plugged in so is pretty much nailed on to be an issue on the main pcb.
You are right as well the cables are a real menace to plug back in.

Just had a look at the schematic and you are right, it shows tr7 and tr5 for motor 2.
I will check them out tomorrow

With regards having it out of the case it makes no difference, mdv2 still wants to spin.
Sometimes it is getting so little power it is hardly turning and sending it a command brings ...

Thanks for the reply.
Yes swapping them gives the same result.
Just having a drive in position 2 gives the same and just having a drive in position 1 gives the same format failed result although I suspect cartridge.

Yes I just went off the service manual with regards transistor responsibility.
I ...

As the title suggests I have an issue with the microdrive.
Now I am new to the QL and have had a good look through the forum and can't find anything which cures my issue.
I purchased this QL about a month back from the car boot, visually it is in great condition.
It fires up and everything seems to ...

Hello to all the QL enthusiasts on here.
I am new to the world of the QL and like many others before me have come here looking for help.
My name is James and I just love retro computers.
I was a Commodore fan back in the day which may not go down so well in here.
Looking forward to gleaning some ...