Piggyback 4164 to Diagnose Memory Fault

[Popopo]

One thing I've noticed is that as soon as the power is applied to the QL then MDV2 spins up for a couple of seconds

This is as soon as power is supplied (as I never get to the option to press F1/F2 for the normal MDV1 spin up)

Does it happen also when you do a reset? or only with powering up the QL?

[t0nyt]

Does it happen also when you do a reset? or only with powering up the QL?

Only when power applied, doesn’t happen on a reset

[Popopo]

Does it happen also when you do a reset? or only with powering up the QL?

Only when power applied, doesn’t happen on a reset

That is important. Now someone with a QL in good working conditions for both MDVs can tell you if that is the normal behavior or something is wrong.
For what you say (My MDVs didn't work so cannot ensure you), I understand that is OK. Like in a PC booting up, the check from BIOS that Floppy, keyboard, hardisks, etc were present or not.

[t0nyt]

Does it happen also when you do a reset? or only with powering up the QL?

Only when power applied, doesn’t happen on a reset

That is important. Now someone with a QL in good working conditions for both MDVs can tell you if that is the normal behavior or something is wrong.
For what you say (My MDVs didn't work so cannot ensure you), I understand that is OK. Like in a PC booting up, the check from BIOS that Floppy, keyboard, hardisks, etc were present or not.

It’s definitely not normal

On my good QL the only time an mdv spins at start is after pressing F1/F2 and no floppy attached

And only mdv1 spins, not mdv2

[Popopo]

It’s definitely not normal

On my good QL the only time an mdv spins at start is after pressing F1/F2 and no floppy attached

And only mdv1 spins, not mdv2

Stop me at any time if I mix too much both subjects (this thread and the issue with spinning motors from MDVs).
Do you use any kind of mapping drivers? That could map MDV2 as MDV1?

Happen it too with MDV1?

At any case... that is a pretty simple test if you have 2 QLs...
Take the MDV2 from the QL that works completely right... and try to check it on the QL that you have the issue.

And.... the most important thing... Are both QL the same version?
Cause perhaps one ULA version force to spin MDV2 at booting time while the second version doesn't.
Just giving you options because I am not expert in QL Scene.

[t0nyt]

I don’t want to touch the good QL but will probably try switching drives around in the poorly QL if the ribbon cables look like they’ll survive it

Thanks

[t0nyt]

Well the MDV2 problem is something I've had to put to one side for now

When swapping the MDV's around I knackered the ribbon cable ends on what was MDV1 (managed to get it connected temporarily as MDV2 which seemed to show the "running mdv2 at power on" problem stayed with the position rather than moved with the MDV, so motherboard related I guess)

For now, until I see whether the QL can be bought to life again, I've left the MDV out of the QL. If it comes to life I'll re-strip and re-tin the ribbon cables on the MDV I've removed

[t0nyt]

Tried to re-tin the ribbon cable, no luck as I can't get it thin enough and some buckle on insertion (my soldering skills and eye's aren't up to the job - got an eye appointment in a weeks time!)

I thought maybe I could solder a straight 2.54mm pitch header onto the end of each ribbon, but when I checked the header fit to the mobo I found the pins are too wide to push into the socket on the mobo (the pitch is fine, it's the pins themselves that are too large)

I was wondering if anyone knew of a source of a header with pins thin enough to fit in the mobo socket please?

Many thanks

[t0nyt]

Looks like it’s SIL connectors I need, so have ordered some samples

[Chris_68]

Hi

Get the ones that are turned, they have thinner pins. If you have solder paste put some in each before you insert the cable.