C103225 REV.2

[KD4CBM]

Here is my C103225 REV.2 STFM board awaiting mandatory upgrades and 4 Meg upgrade.

C103225 REV.2 USA

IMG_4271.jpeg (906.75 KiB) Viewed 3757 times

[exxos]

One of those odd revisions I don't seem to see very often.

[MacTech05]

KD4CBM,

That is same motherboard I have in my 1040 STFM. You don't happen to have a schematic specific to the motherboard, do you? I am trying to locate the Reset circuit capacitors so I can replace them.

Thank you
Randy

[rubber_jonnie]

KD4CBM,

That is same motherboard I have in my 1040 STFM. You don't happen to have a schematic specific to the motherboard, do you? I am trying to locate the Reset circuit capacitors so I can replace them.

Thank you
Randy

From what I can see looking at a bunch of schematics, the reset circuit is much the same across all boards and uses a 556 IC labelled either U2 or U37, so you'll be looking at the electrolytic caps surrounding that and that are connected to it.

[MacTech05]

rubber_jonnie,

I will check that out.

Thank you.

Randy

[MacTech05]

rubber_jonnie,

Thank you for the info on finding the Reset Circuit capacitors on my 1040 STFM. While I still have not found a schematic for my 1040 STFM motherboard, I did find and download a different 1040 STFM motherboard schematic. Based on your information, I found the Reset Circuit capacitors immediately on the schematic and on my motherboard. I have replaced the capacitors.

Thank you!
Randy

[rubber_jonnie]

rubber_jonnie,

Thank you for the info on finding the Reset Circuit capacitors on my 1040 STFM. While I still have not found a schematic for my 1040 STFM motherboard, I did find and download a different 1040 STFM motherboard schematic. Based on your information, I found the Reset Circuit capacitors immediately on the schematic and on my motherboard. I have replaced the capacitors.

Thank you!
Randy