Motherboard C-120 value and replacement info

[twoodland]

Can someone with a schematic tell me about the motherboard component C-120? There are a bunch around the VDP RAM section. I would like to order a replacement part, and a recommendation would be appreciated.

 

 

 

 

 

[HOME AUTOMATION]

At a glance these appear to be decoupling capacitors for the DRAM. They look very well sealed...But who really knows without diagnostic tests. Probably .01's. I have the TI schematics in print... not sure where... might be one on the resource page here...

Edited December 12, 2018 by HOME AUTOMATION

[+Lee Stewart]

Schematic shows C120 as 0.1—as are C121 – C127.

 

...lee

[+FarmerPotato]

Can someone with a schematic tell me about the motherboard component C-120? There are a bunch around the VDP RAM section. I would like to order a replacement part, and a recommendation would be appreciated.

 

C120.JPG

 

 

 

 

Those are all 0.1 uF filter caps per the schematic. There is one between each voltage pin +12, 5, -V to gnd.

 

They appear to be glass, as in this style: https://www.goldmine-elec-products.com/prodinfo.asp?number=G23426

Found under "Rare or estoteric" parts.

You could substitute this one at 0.15uF https://www.goldmine-elec-products.com/prodinfo.asp?number=G23436

 

They have polarity.

 

You should be able to substitute any 0.1uF aluminum electrolytic.

[HOME AUTOMATION]

I hate those cans, If that's what you mean... I always go with TANTALUMs!

[twoodland]

Thank you all so much! I have replacement parts on the way!