Commodore Executive SX-64 question

[rob_santry]

Hi Group,

I traded some of my vintage computer gear for an SX-64. One thing I notice is that when I first turn it on, the hard drive initializes and then I see a grayish screen. There is no white screen with the typical Commodore startup screen. I immediately reset the machine and everything is fine. Also, after the machine warms up, I can start it up just fine although it can take a moment for the normal screen to appear.

I wonder if one of the rom chips need to be re-seated? I haven't taken it apart yet but I think I may do that just to do a dusting, cleaning, chip re-seating, and floppy drive cleaning.

Thanks in advance...

Rob
Grants Pass, OR

 

[Deleted member 14264]

1. There is no such thing as a hard drive in the SX-64 or any Commodore 8 bit computers as sold by Commodore.
2. The problem you have seems to be with a capacitor used by the 556 timer circuit responsible for the initial reset signal.

Check the schematics of the SX-64 available on Zimmers and all capacitors connected to that chip. AFAIK only one is electrolithic and that's the one which needs replacing.

Since you're in the U.S. it is easy for you to get in touch with Ray Carlsen for advice or service.

 

[rob_santry]

Hi eslapion and thanks. I mis-spoke. Obviously. Yes it is the floppy drive that initializes. My bad.
I have a schematic and so I'll look at it to see which cap it might be. I'm sure it is one of the electrolytics. I'll contact Ray Carlsen as you suggest.

Other than the quirky startup issue, the machine runs great and is in immaculate shape, so I'm pretty stoked! Thanks again...

 

[Deleted member 14264]

I checked this on Zimmer's :
http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/c64/sx-64/251103_l.gif

I think the component you want to replace is C47.

I'm starting to have exactly the same problem with my old VIC-20 with PET style keyboard (1981).