Ultimate64 – Cartridge slot problem

Before you start to read this post I know that Gideon has tried to obtain better quality (card edge) connectors from several suppliers. So far no luck. Gideon put very much effort into the Ultimate 64 boards. He tried (and did) to give us a Commodore 64 replacement board that is future proof, which I appreciate enormously!! So don’t read this post as a negative post!

The problem that can occur

Some cartridge slots (egde connector) on the Ultimate 64 can’t handle cartridges without V-shape beveled PCB’s, so be carefull with those carts, they can damage (bend) the pins of the edge connector.

Bended pins:

 

Cartridge PCB thinkness & bevel does it matter ?

Cartridge Thinkness (mm) PCB Edge
Mssiah 1.60
MS Pacman 1.75
Ultimate 1541-II 1.60
Kerberos 1.50
The Final Cartridge III 1.55
Action Replay 1.60
Power Cartridge 1.60
Sound Expander 1.70

I tested the above mentioned cartridges and I experienced resistance on all the cartridges without a round of V-shape PCB bevel. In my opinion it has everything to do with cartridges that are not beveled and not especially the thinkness of the PCB.

If we compare the Sound Expander cartridge (1.70mm/V-Shape bevel) and Mssiah (1,60mm/straight, no bevel), I can insert the Sound Expander cart pretty smooth, but to insert the Mssiah cart I have to apply more pressure, keep in mind that this cart is less thick.

Try to avoid damage

Check PCB bevel

If you look into the cartridge sideways, and feel the pcb edge, does it feel edgy of a bit smooth ?

Don’t try to insert the cartridge into the U64 if the edge (no bevel) looks like:

You can try to insert the cartridge gentle into the slot without excessive force if the edge (V-Shape bevel) looks like:

I’m not so sure about this kind (Rounded) of bevel:

It’s your own call to try it! I can’t be held responsible for damaging the slot!!

 

The way I insert the carts into the cartridge slot

Try to insert the cartridge into the cartridge slot like this. The presure points are spaced more equaly.

 

Difference between edge connectors

The edge connector that’s used on the Ultimate64:

The edge connector that’s used on the original Commodore 64:

Damaged edge connector? Replace it..

BEFORE REPLACING THE EDGE CONNECTOR, CONTACT GIDEON ABOUT THIS. I DON’T KNOW THE WARRANTY POLICY REGARDING THIS.

I harvested an edge connector from a scrap board and used it to replace the one on the U64 board.

To remove the U64 edge connector you first have to remove the metal cage.

After that I advise to add fresh solder with lead to all the pins before desolder them, because the U64 edge connector is soldered with solder without lead and that’s quite hard to remove.

CAUTION: To minimise health hazards when using solder with lead & flux, use a fume extractor!

ONLY REPLACE THE EDGE CONNECTOR IF YOU OWN A DESOLDERING STATION!!

WITH A SOLDER PUMP IT WILL BE A CHALLENGE!