Mdv1 + Trumpcard infinite spinning

[Popopo]

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).

Just putting some ideas on the table:
1. Power regulator has not enough energy to feed the Trump Card and the rest and introduce some fake signals in the ULA that controls the MDV1
2. The trump card may put on the signal to access to the MDV1 so it is spinning all the time.
3. Did you place the shield for MDV in pos1?

So... which power regulator do you use?
May you check the capacitors on the Trump Card and its power regulator?

I have not a trump card to compare signals with you but maybe another user has it and may check it out with the oscilloscope.
Keep in mind (sure you know but...) there are some mandatory mods to do in the QL main board in order to improve and fix some problems with MDVs.

Recently an user told me some "weird" behaviors with his MDVs but also with MDPs also when using a expansion board (in this case it was a RAM expansion), when I asked to change the +5v power regulator and put in the original one (linear one) all the problems disappeared.

[Cristian]

Hi Popopo, and thanks for your ideas.

1. and 2. The Trump card works fine on a second QL, also with the first QL when Mdv1 unit is replaced.
3. Yes
I use the original voltage regulators (7805 if I remember correctly). I can not check the capacitors on the Trump Card, but I can check the voltage regulator.
The mandatory mods in both QL main boards have already been done.
I suspect the problem is in that MDV unit itself. I'll try to swap the units (also with the second QL)