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Faulty MVS Progress Update #2 - No Video No Audio - Bad Sound Chips?
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- čas přidán 14. 08. 2012
- Quick progress update #2 on my faulty MVS project. So far I've managed to hook everything up but I get no audio or video. The Yamaha YM2610 chip which sits near the rear of the board is also getting very hot and I suspect it was maybe damaged by the battery leak. Suggestions are always very welcome! :)
Check out Thomas3120's channel out...
/ thomas3120
He's also doing an MVS project repair and does loads of cool videos on his other mods/custom consoles/robotics projects.
Thanks for watching!
I suggest before start de-soldering the big chips you should find the power and ground of the Yamaha and Z80 chip and cut only those legs first and then power the whole thing up.
Cut first the power of Yamaha then test, then if nothing cut ground of Yamaha then test.
Cut z80 power and test and etc you should get something on the screen, since these boards do have some BIOS checking . (and install the bios of course...)
I've been subscribed to both of Jeri's channels for a while now :) . She properly knows her stuff! I watch her vids and try to follow/understand but a lot of what she does is WAY beyond my level of understanding. I clearly have a lot to learn, haha :P. It's still always really interesting to follow her projects.
I keep on watching for updates on this like the stock market or something super excited to see if this ends up working
I'm always interested in listening to you ramble for 10 minutes! xD
anyone who finds martin boring when talking about something education like eletronic shouldn't even be on his channel. martin, keep doing your thing man. your videos are great!!
I have a 4-Slot MVS Board. The Sound was a bit odd in that the Music was louder than the Game Effects. Turned out I had to replace the Yamaha YM2610 IC. Sound is OK now. $8:00AUD fix.
The chips on this board aren't advanced enough to require cooling :) The Z80 is the CPU that was inside the ZX Spectrum and runs at a whole 4MHz, and the Yamaha sound chip is just a sound generator and shouldn't even warm up. It wasn't until the mid 90s that CPUs ran fast enough (and consumed enough power) that they'd get hot enough to need cooling.
Lol, well I think you deserve a round of applause making it all the way through :P .
You should definitely give it a go! It's really not that difficult. Very rewarding when you manage to fix something!
If chips get hot like that, they've usually shorted out inside. What happens after that can be completely random depending on how the chip died and what's shorted out in it.
Try removing the Yamaha chip (it's the actual sound chip so beyond making sound it shouldn't be doing anything important) and see what happens. If you're lucky you might get an error telling you the sound chip is missing or bad.
I had the same problem with my MVS i got, I didn't have an JAMMA connector so i had to solder directly from the pins to the SCART. When i tried it on both of my TVs it switched to the channel but no picture, same problem as you. I then changed the sync pin on the scart from 20 to 19 and i got picture :).
i have a cdtv which had no video, turned out to be bad caps on the video board, it seems your issue with video may be similar as it seems your tv is picking up a signal, however no RGB from the video stage, with the sound it may be a similar issue, may be worth getting hold of a chip schematic and checking voltages on power pins and use a logic probe to test channel outputs if not just drop in another 2610 or 2608 which is similar
Just bought a Old Megadrive 1 for exactly that Chip, will have to post Videos of the finished product
Thankfully I think the MVS boards are just a single layer with traces on either side. It's still challenging enough though! :P
Hey can you please make a video to how you wired that scart connector to the jamma harnes I really need one to do some testing
hell yes I want to get a MVS too and will prob get a cheap one with faults to fix up so this will be very helpful ty :)
Maybe there is a trace coroded under the DIP-IC beside the Battery. The acid seems to like to spread underneath parts unfortunately.
Haha, thanks dude!
Just got done watching Luke's vid on the Unibios. Definitely going to pick one up as the next step. I'm really interested to see how yours will react when you test with Unibios and the missing RAM. With mine I'd just like to get it to show anything on screen. Even an error message would be nice! lol
I was interested to read about the Gen/Mega similarities too. Someone told me I could even use a Z80 from a model 1 Mega Drive. I'll still need to find a YM2610 though.
You can take a Z80 out of a dead Model 1 Mega Drive/Genesis or even an old Master System. I've seen a bunch of them Z80's die for no reason. What's the voltage on pin 57 (/SCS) of the YM2610 when the system's 'running'? If it's somewhere between 2 and 4 volts, the Z80 is accessing it properly. Is the voltage on pins 19, 28, and 62 5 volts? if not it may be shorted out.
take it you are going to desolder the yamaha chip and check below it? i'd agree that if the battery leaked it may well have leaked in below
good vid dude ! always worth a watch !
Epic your videos are brilliant very interesting information. I watch another guy from America called Ben Heck who also mods technology and regenerates retro hardware good stuff addictive watching thanks for making them.
it looks like its missing a bios chip from the centre there
Did you ever get this working? I've done a recent repair to an MV-1FZ but luckily I didnt have any battery acid - that stuff is really painful... I suspect you could have damaged tracks under the components nearby, it often doesnt stop just at the battery area and can damage the tracks underneath chips easily.
I also noticed you've got a socket there with no chip in it - presumably a missing BIOS?
My bad - skipped around and missed your point about the BIOS :P
The board will not do anything without a bios chip installed.
i have a question
if you ever find a sega cd 1 pal could i pleas buy it?
I think your floor is on LSD.
Lol, well that's good to know!
Lol! EVERYONE is repairing these things lately.
Any updates Fella
Probably worth swapping the capacitors with some new ones as the old ones might be broken. ASSEMberX has a good guide! /watch?v=_UY5ouIXVQc
o nevermind lol.. i guess i shoudlve waited ten seconds