The screen works just fine, the sound works, the cartridge slot
identifies the game loaded in, but on power-up I cannot get (and
have never seen) the menu, and any game comes to a stop at Player
1 immediately after the requisite title screen. This happens
whether the controller is plugged in or not. That it can read
carts, play into tunes and display legible information about the
game before coming to a halt means, I assume, that things like
the processor and timing are good.
Does anyone have any experience of this kid of fault or any
suggestion of where to go from here? I've been scouring the
interwebs and I've found suggestions that the AY-3-8912 could
perhaps be responsible. I still have two Amstrad 464's in the
loft - I'm wondering if I should crack one of those open for some
donor parts as I believe they used the same chip (and may even
have one in a DIL socket for easy extraction), but I thought I'd
ask here in case someone had any information that might save a
wild goose chase!
Unfortunately, mother didn't perform her due diligence too well, and the example from off eBay has seen better days. It had a fault from
day one - Minestorm would appear on power up unless another cart was already inserted. I assumed that's what it was supposed to do, it
was only later I learned there was a menu screen I'd never seen.
On Thursday, December 9, 2021 at 1:54:09 AM UTC-6, djsa...@gmail.com wrote:
Unfortunately, mother didn't perform her due diligence too well, and the example from off eBay has seen better days. It had a fault fromWhat menu screen??? There is no menu screen if there is no cartridge inserted. Just Minestorm. Your machine is indeed doing what it is supposed to do.
day one - Minestorm would appear on power up unless another cart was already inserted. I assumed that's what it was supposed to do, it
was only later I learned there was a menu screen I'd never seen.
G
Anyway, the good news is that she lives! We're no longer hanging
at the Player 1 screen and both Minestorm and cart games are
progressing into the playable (and they play juuuust fine). Thank
goodness I didn't have to try to desolder that AY-3-8912... yet.
That might still happen though as I still have the original
problem of the splash screen not appearing. If I hard power it on,
it draws very briefly before Minestorm takes over. It's still acting
like a button is pressed somewhere causing it to skip.
David Savery <djsa...@gmail.com> wrote:
I wonder if there might be some excessive ripple on the 5V power
line, which is worst straight after power-on? The capacitor could
then keep the voltage at the controller input below the (raised)
HIGH voltage threshold when there's a voltage spike on the 5V
power line. Just a thought. You'll need an oscilloscope to
effectively view spikes/ripple on the 5V line, it would be caused
by either failing filter capacitors or a failing 5V voltage
regulator. But that's just one theory.
--
__ __
#_ < |\| |< _#
Sysop: | Keyop |
---|---|
Location: | Huddersfield, West Yorkshire, UK |
Users: | 366 |
Nodes: | 16 (2 / 14) |
Uptime: | 05:55:04 |
Calls: | 7,816 |
Calls today: | 4 |
Files: | 12,927 |
Messages: | 5,767,182 |
Posted today: | 2 |