mega cd 1 black screen with drive noise

hi ,

Iam still struggling with model 1 sega cds consoles, now I bought another as is mega cd 1 Japanese, it wont power on, replaced all caps, cleaned the teeth of connectors , even tried several bios chips from many regions and a region free bios chip (Japanese mega cd comes with a socket bios so its easy to replace)

all what i get is black screen , a few times some noise colors that disappears on screen, noise in drive and it keeps running the gear of the lens about to break it, tried many drives all the same, when I remove the cd drive cable I get still bios screen (not moving , no music)

those drives I tried are working ,2 psus working tried as well, tried a multi system genesis model 1 , and a genesis model 2 (with model 2 always black screen).

so what else did I miss ?????

 

no clue ?

 

quite bad that no one is even reading

anyways i found something toooo new to me , if you install just the main board to a mega drive you will get a frozen bios screen, it even gave me only once full working bios, how on earth is this possible !!

now i even get by the board alone the frozen bios screen with green ready light on !!

is this rational?! obviously the psu is no good as it makes no difference to connect or even remove it !!

 

No help?

 

Hi, just FYI when you reply to your own thread it makes people think that there are more replies here then there really are. It looks like two people replied to you when scrolling through.

The Sega CD should produce its own image without the drive or laser connected at all. That's what the BIOS has stored in it, and as long as your RAM, CPU and ASICs are ok u should be doing pretty well.

Are you still getting the black screen? If so you need to check for corrosion and pin damage as as well as capacitor replacements and any shorts on the power rails. If you are getting a bios image then the problem is different..

also look at the mega cd service manual. There is a repair flowchart and lots of useful information.