Sega Mega Drive freeze issue and no sound issue.

[suverman]

Hi guys, this be my first post.

Please do not respond by asking me to just buy a cheap one off ebay or something.

I got a Sega MegaDrive with stereo sound(used to be). Got it used from a dubious place.


Now, I was using the Mega Drive 2 adaptor to run it, the console used to freeze within seconds
of startup screen of the game. Not always though, at times it got started and continued
without a problem. I didnt get proper tuning with the RF jack so I used the headphone jack,
andI could hear the sound faintly but with a lot of humming, eventually the sound just died.

I have since then acquired AV cable and a DC power supply that can supply 0 - 2A of current
and voltage can be set from 1- 16V. Its got 2 digital screens to show me the current being
drawing and voltage I set to 10V.

I have noticed this:
The moment I turn on the MD,

Current reads from .7 amps and gradually drops to .65 amps within 5 secs.
Eighter the game doesnt bootup or it just hangs.

Current reads from .7 and doesnt drop below .68 amps till the game starts
The game bootsup and runs, and usually keeps on running without ANY problems (except lack of sound).

If I drop the voltage to like around 7V, the current drops too, I can hear humming
sound from the headphone, but even when I tune the supply back upto 10 / 11V, the humming
goes away, but I can still hear no sound.


Questions:

1) When the MD is rated at 1.2A, why does it NEVER draw more than .75 amps? Infact each time it draws less than .68 amps at the booting time, the megadrive doesnt even run.

2) Sound dissapearing, shouldnt there be some visible evidence of say something burnt etc. How do I check
what is th cause for the sound to dissapear?

Thanks a bunch guys.

[bust3dstr8]

Questions:

1) When the MD is rated at 1.2A, why does it NEVER draw more than .75 amps? Infact each time it draws less than .68 amps at the booting time, the megadrive doesnt even run.

2) Sound dissapearing, shouldnt there be some visible evidence of say something burnt etc. How do I check
what is th cause for the sound to dissapear?

Thanks a bunch guys.

Answers....

1) Us mortals shall never know, maybe if you write to Sega's Develpment deparment
they will enlighten you.

2)Many things are not as the appear to the naked eye, I would fly to M.I.T. and see if they
will let you use their Gamma-Ray Pulse scanner.

[APE992]

Probably what was available cheaply and so they had headroom in case a Genesis revision needed more power than the last.

You NEVER get a power supply capable of exactly 100% of your "requirements". Just asking for trouble.

[suverman]

Probably what was available cheaply and so they had headroom in case a Genesis revision needed more power than the last.

You NEVER get a power supply capable of exactly 100% of your "requirements". Just asking for trouble.

Yes, what I was getting at, was, is there any component that is failing, resulting in such odd behavior? Could it be faulty power regulator transistors? What happens if the transistors malfunctions?

[Sunnyvale]

Yes, what I was getting at, was, is there any component that is failing, resulting in such odd behavior? Could it be faulty power regulator transistors? What happens if the transistors malfunctions?

Methinks he's saying don't expect the specs to line up properly, they came outta the factory that way.

[APE992]

Methinks he's saying don't expect the specs to line up properly, they came outta the factory that way.

Indeed.

Yes, what I was getting at, was, is there any component that is failing, resulting in such odd behavior? Could it be faulty power regulator transistors? What happens if the transistors malfunctions?

That isn't odd behavior. 100% normal. If it was drawing above 90% of the rated maximum I might be a bit concerned but finding it as low as you did isn't anything to be concerned about.

What in the world made you think it was odd behavior?

[suverman]

Answers....

1) Us mortals shall never know, maybe if you write to Sega's Develpment deparment
they will enlighten you.

2)Many things are not as the appear to the naked eye, I would fly to M.I.T. and see if they
will let you use their Gamma-Ray Pulse scanner.

A simple "I don't know." or better yet refraining from even posting something would have been
better that this useless sarcastic response.