Re: MTX 512 (debugging thread)
Posted: 13 Aug 2020 20:30
Thank you for your replays, I'm still planing on swapping out the VDP crystal, because it's easy and cheap to source. But today I watched an episode of Noel's Retro Lab, where he fixes a SVI 328, that also uses the the same graphics chip TMS9929ANL (VDP) as MTX.
https://www.youtube.com/watch?v=KSrMwfn ... e=youtu.be
His symptoms are identical to mine, missing video and no clock on VDP. So as a backup plan if swapping the crystal won't help I would also like to source a new TMS9929ANL. Chinese sell these, but from the feedback they are mostly fake/non working. Does anyone have any suggestions where i might find a good one?
My reasoning is that its more likely that the VDP is causing the clock issue than the other way around, because for a couple of seconds if the machine is cold all works fine and the picture is in sync and without artifacts. I presume if the crystal would be at fault it would not work from the begging and not fail after the machine gets "hot" (runs for a while).
Does this sound reasonable? As always any suggestions are most welcome and thank you for your help.
https://www.youtube.com/watch?v=KSrMwfn ... e=youtu.be
His symptoms are identical to mine, missing video and no clock on VDP. So as a backup plan if swapping the crystal won't help I would also like to source a new TMS9929ANL. Chinese sell these, but from the feedback they are mostly fake/non working. Does anyone have any suggestions where i might find a good one?
My reasoning is that its more likely that the VDP is causing the clock issue than the other way around, because for a couple of seconds if the machine is cold all works fine and the picture is in sync and without artifacts. I presume if the crystal would be at fault it would not work from the begging and not fail after the machine gets "hot" (runs for a while).
Does this sound reasonable? As always any suggestions are most welcome and thank you for your help.