MegaDrive VA4 won't do hard resets

[TmEE]

One cannot do anything regarding SMS mode from MD mode. When MD games work then there's no reason SMS games wouldn't work.

[lumclaw]

One cannot do anything regarding SMS mode from MD mode. When MD games work then there's no reason SMS games wouldn't work.

Maybe he's encountering the problem JVC X'eye has? That will start in SMS mode, yet reset from MD mode into SMS mode is glitched.

[evildragon]

I think I need to get myself a powerbase converter of my own and a master system game to try to see if I can find out what's different

[lumclaw]

For the right price that's OK.

I wouldn't suggest paying more for powerbase converter than a whole working master system.

[evildragon]

Ok I found the problem.. There's a burnt cap on the bottom side of the board.

Here's the other problem, it's not marked nor is it labeled with a Cxx number.. I have NO way of knowing what to drop in here..

[TmEE]

Those caps are all filter caps, either some 0.1µ (dark brown and only between GND and VCC) or some 10..47pF (light brown) and on some signal lines. Lack of power rail cap would not cause anything, not so sure about the 10...47 kind though.

[evildragon]

These are the light brown ones (cream to my eyes)..

I did notice this though.. One of the VCC lines on the cart slot was 5v, the other was 4.6v.. One of the VCC's are low. Also, Krikkz said that address line 21 should be pulled to ground when in MS mode, but it's not, it's floating at around 3.7v.. So I tried pulling it to ground myself and it didn't do anything.