Mega CD 2 repair question...

I've just picked up a seemingly dead mega CD 2. The fuse checks out but I'm getting no power, no drive movement, no power led etc.

Before i start fault finding, if I disconnet the optical drive completely, will the mega CD still make it to the start up screen or will it being unplugged stop it starting?

 

Further to this;

Setup - PAL Mega Drive 1 - PAL Mega CD 2

Mega CD 2 is generally in good clean condition internally and I've given the slot a good clean with IPA.

Current symptoms - Mega CD does not power up - no LED no disc spin

So I've done the initial tests.

PSU is fine
Fuse is fine
V Reg is spitting out 5v on pin 3 as expected

When I power cycle the Mega Drive my TV does detect a signal (576p) and I see some slight ripples in an otherwise totally black screen.

Just wondering what my next steps should be?

 

it will boot without the cdmech. there are several fuses. check them all. also if u fix the power issue. make sure to clean the blade switches so to not blow the fuse again.

 

Are you sure? I only see F301 on the schematic and BoM for the Model 2 Funai Mega CD I'm working on.

 

there are at least 2. one on the top side of the board and one on the bottom. I remember cause i got a broken one a couple of years ago. It wouldnt power on. I turned to google saw it was a common problem. However the fuse listed in most places was working.
It turned out to be another fuse that was blown.

 

There's definitely only the one fuse on my board revision.

https://console5.com/wiki/File:Sega_CD_2_-_Mega_CD_2_-_Service_Manual,_Number_002,_August,_1993.pdf

 

this vid describes the two fuse variations. The one that mine had was the surfacemount type.

I se you might have the other kind.

 

If not the fuse is bad check the nec power reg.

 

just updating this for prosperity. I received my Mega Sg a few days ago and decided to let it have a go with this Mega CD. I finally got the Mega CD to boot to a BIOS screen and subsequently loading games. I'd previously tested it with 3 original Mega Drives (2 MK1s and a MK2). It has to be an issue with the edge connectors on the expansion ports on those consoles as the shiny new Mega Sg just works.

 

That's strange. I doubt your system is fixed, but you probably have an issue with the VREF, or similar signal that the new system doesn't use.