GUIDE: Telling apart good Genesis 1s and Genesis 2s from bad ones.

[TmEE]

left is blurry... reason for that is that there is no phase syncronisation to video signal

[omp]

Sorry but this was very frustrating for me, the pics couldn't show what I wanted. I should not have mentioned anything till I had clear photo's. I asked the wife to look (from a impartial view) and to her on that tv the added oscillator was cleaner/clearer. To be honest I was so fucking mad (as the internet is serious business), I asked Joe to ban me for a month so I couldn't log on and say anything stupid/regretful. He told me "just leave". I am sorry for any confusion I caused, I was just trying to help. I will stick to my guns and say the added oscillator cleaned shit up. The weird thing is, my modded mega drive 2 that uses the standard frequency for pal duties and a 3.5(something something)mhz oscillator for ntsc.gives exactly the same quality image (good mb3514) when switched. Again sorry.

[villahed94]

The MB3514 doesn't show as many artifacts with the squearish 3.57945 mhz frequency coming out from the clock divider than on a CXA1145.

[Ace]

I've got some new information on the Genesis 3 for everyone. Head to the first post to have a look.

[Ace]

Just acquired a VA2 Genesis Model 1. Much to my surprise, this particular VA2 actually DOES have correct Mono audio. I remember hearing about certain early motherboard revisions of the Genesis Model 1 having Mono audio that's missing the left audio channel, and TmEE told me this problem exists on motherboard revision VA2, but the one I have has both the left and right audio channels out of the A/V out and RF box.

However, this Genesis is in serious need of work. The video looks TERRIBLE (MAJOR rainbow banding and even Top-Loader NES-style vertical lines!) and the audio is completely screwed up out of the headphone jack. At first, there was a layer of distorted audio at low volume on both the left and right audio channels, and the left audio seemed louder than the right audio channel. I remember my 1989 VA3 Genesis Model 1 having this same problem with distorted sound at low volume on the left audio channel and this was caused by a faulty low-pass filter cap (one of the ceramic caps on the underside of the motherboard). So I replaced both those caps on the VA2 Genesis Model 1 with the same value caps (5600pF according to a schematic I found)... the sound is now EXTREMELY muffled and the right audio channel is even quieter than before. I'm guessing the caps on the CXA1034's outputs are bad?

[ApolloBoy]

Kinda sounds like how my VA1 Japanese MD was, a complete recap of the system should take care of it.

[villahed94]

Just acquired a VA2 Genesis Model 1. Much to my surprise, this particular VA2 actually DOES have correct Mono audio. I remember hearing about certain early motherboard revisions of the Genesis Model 1 having Mono audio that's missing the left audio channel, and TmEE told me this problem exists on motherboard revision VA2, but the one I have has both the left and right audio channels out of the A/V out and RF box.

However, this Genesis is in serious need of work. The video looks TERRIBLE (MAJOR rainbow banding and even Top-Loader NES-style vertical lines!) and the audio is completely screwed up out of the headphone jack. At first, there was a layer of distorted audio at low volume on both the left and right audio channels, and the left audio seemed louder than the right audio channel. I remember my 1989 VA3 Genesis Model 1 having this same problem with distorted sound at low volume on the left audio channel and this was caused by a faulty low-pass filter cap (one of the ceramic caps on the underside of the motherboard). So I replaced both those caps on the VA2 Genesis Model 1 with the same value caps (5600pF according to a schematic I found)... the sound is now EXTREMELY muffled and the right audio channel is even quieter than before. I'm guessing the caps on the CXA1034's outputs are bad?

YES! My VA2 suffered from that same problem of distortion at low volumes, even after recapping! It seemed like if the CXA was burnt or something.
Unfortunately, it doesn't want to boot anymore, and I'd like somebody to repair it for me.
Forgot to mention, mine did output both channels in an equal proprotion in mono outputs.

[villahed94]

Just got another VA2 Model 1, and its serial number is 39U07056. This makes me wonder on which production run VA3 was introduced.
Ace, would you like to post the serial number of your VA2 and your VA3 Model 1s?

[Ace]

I don't have access to my consoles right now, but I know for a fact one of my VA3s and my VA2 both come from the same factory, though they seem to be two production runs apart (both were made in 1989). My other two VA3s were also made in the same factory but in 1991, and I *think* they were made during the same production run. I'll check that for you later.

[Solkia]

Um, I have a question.

My Model 1 is a HDG model 1. But it says both VA5 and VA6 on the board. Which is it?

[omp]

Read the chip that is above/below it. I can't think of the number off the top of my head but for example

VA5 - 12345
VA6 - 54321

So read the chip above/below it and bingo there your go!

[Drakon]

Read the chip that is above/below it. I can't think of the number off the top of my head but for example

VA5 - 12345
VA6 - 54321

So read the chip above/below it and bingo there your go!

You guys are jokers. The va6 will have tmss, the va5 won't have tmss.

[villahed94]

You guys are jokers. The va6 will have tmss, the va5 won't have tmss.

VA5 does have TMSS but when it's set to English. If it's set to Japanese, it won't appear.
VA6 does have it on all settings, though.

[Drakon]

Really? Guess that's what I get for buying a japanese va5.

[villahed94]

Yes. VA5 was originally intended to be the first TMSS revision, but due to an internal design error in the ASIC, English setting would trigger TMSS, while Japanese wouldn't.
VA6 was designed mostly as an oops revision, and IIRC both the 315-5402 and the 315-5433 are pin compatible each other.