When you say you get continuity between the NC and NO contacts how low is the resistance reading ? Also what is the reading with the test leads shorted together ? (So we can correct for the resistance of the test leads.) Was the test done with the board totally disconnected from the bed ? Do all 8 relays give the same readings or is it only the ones that drive the motor that is not working ? What type of motors are they and what voltage ? (PM. series (universal.), induction with or without capacitor start.) Are you referring to the black items on the right of you picture ?
DO NOT try to connect 24 volts to the relay coils while they are still fitted to the board or there is a good chance that you will destroy the ULM2803 driver chip. Also a picture showing all of the board would be helpful. Can you trace out the schematic around the two relays that you suspect are causing the problem ? (Or at least post a picture of the etch side of the board.)

Les.

 

Couldn't see the actual Linear actuator in the cat. but most show DC either 24v or 12v DC.
Max.

 

If you can get your hands on a powered desolering station, you most likely can have those through-hole relays off the board in minutes. Something like this:

https://www.amazon.com/Desoldering-...VH9DGBDNQH333C74VNBV&qid=1567947495&s=gateway

 

It's hard to read um. Two I couldn't get any numbers from. The other two (as best I can tell) are:
T5250
6A04

and

T5246
?A04

 

Do they look like this?
Max.

 

Are these the ones at top right in the pic?
Is there any marking on them?
JU1 etc, J generally means Jack.
Max.

Or "jumper", quite appropriate for this board.

 

Actually the J notations were adjacent to jumpers that I missed.
Max.