Home Forums General Discussion Technical Questions Dover Solid state with high leg

1974 dover solod state
Highleg
With all wires in place
does not respond to hall or car call
Door operator has no power
If ina is removed from terminal car runs up (nothin is jumping ins to u)

If u is removed from terminal
Door operator works
car levels into floor
Car will not run only pump will run valve wont pic

Eevator seems to be stuck on inspection and up if u is on terminal from the selinoid of lu
Pulled all cards car runs up with no cards in
Swaped all cards
Checked 25v across 24d pc blue cap
Replaced rect board with diodes

This happend after a seal was done the only mistake was wrong jumper to run up from a high voltage valve terminal to u which blew the 6 amp fuse # 4
Have isolated high leg by removing #10 fuse problem still happens
??????????
Any ideas

Do you have a set of prints for the job?

Not job specific the prints are from 85

Hmm, I have a generic set of prints I could send you - I don't know if it will be any different than yours.
Unfortunately, I haven't had any experience on one of these.
The only thing I can think of is either a popped capacitor or a short in the safety string; I've seen that a lot on older Dovers. Are you certain fuse #4 is 6A rated - that runs off the transformer, correct?

Yes the fuse holder is still marked and the print shows 6 at this point im leaning towards diode board and caps just goin to replace all and see if that works havent found the exact blockimg board needed . Could a blown cap cause a short in the system?

Check the first 2 terminals on the left (pc & sc) on the power card - should be 5vdc.

Also check pc to 24d - should be about 25vdc; if not you could add a capacitor rated 250vdc 250uf.

and check 9vdc to sc which should be about 15vdc; if not then you more than likely have a bad power card.

Hope this helps.

+1 on the power supply. Especially the 5vdc. And it's adjustable. I keep it at 5.1.

Most of those Boards have a 1uf Cap on them for Outputs. They do decay and fail and are critical. Have fixed many really strange problems by changing a handful of caps on boards. Changed caps to 1uf 50v DC. If the Power supply is correct, chances are you have some bad caps. Finding one bad cap is tough. Usually have to board swap then change all caps.

^^ did all that but your are on point same path i took
^ im goin to replace caps tm
Thank you both im open to all help im really stuck

This is one of the first SS vintage Dover design. The card rack has Capacitors and diodes in the wiring on the back side of the rack/ terminal board. Not easy to get to. Sounds like short burned into circuit. I may have start up check sheet for voltages and resistance if interested.
Maybe 40 years is enough and time to replace control.

Yes I am very interested in the start up paper work if possible and im tryin to limp this unit three more years untill the board will do a mod

Fixed the running up on insp with diode board
Everything seems to operate normal now
Runs up and down on insp as needed doors work good
Will hold calls but only runs pump not picking the valve
??

All fixed
Diode zener board blwon
Wiring from last contractor had limit switch jumped for repair had to put it back
They replaced f1 and took wire off v21 so jumper from v21 to p8 is needed to run now ???