Author Topic: Fluke 8842A Relay K301/K401  (Read 1057 times)

0 Members and 1 Guest are viewing this topic.

Offline omegaone

  • Contributor
  • Posts: 36
  • Country: ca
  • eV = 1 Joule / 1 Coulomb
Fluke 8842A Relay K301/K401
« on: October 13, 2018, 03:14:02 am »
Previous issue with a Blank Display and VFD replaced. Now the display comes on but flickers and goes off.
Suspect relay K301/ K401. If anyone has more info on these particular relays (they used to be active when power is turned on, now they are quiet) and their function please let me know.
Part Number:AZ7-2C-5DE (mechanical relay)
                     R8378-1 (reed relay)

Relay K301 coil checked to be ok (about 90 ohms) and activates with 5 VDC from external input.
No power to the relay when the start button is pushed.
Micro controller U201 pins 1-9 all have 4.8 VDC available but pin 18 and 19 which is supply power to the relay does not have power.

Continuing my troubleshooting with my limited knowledge. If anyone can offer any feedback on my findings please comment!
« Last Edit: October 16, 2018, 12:51:50 pm by omegaone »
 

Offline mzacharias

  • Frequent Contributor
  • **
  • Posts: 667
  • Country: us
Re: Fluke 8842A Relay K301/K401
« Reply #1 on: October 14, 2018, 01:33:27 am »
My 8840A (same model, basically) had the same problem and it was solder connections associated with the power transformer.

They didn't look bad either, but re-soldering them fixed the issue.
 
The following users thanked this post: omegaone

Offline Moonbase

  • Contributor
  • Posts: 22
  • Country: de
Re: Fluke 8842A Relay K301/K401
« Reply #2 on: October 31, 2018, 03:56:21 pm »
Previous issue with a Blank Display and VFD replaced. […]

Just by chance, got a source for the good old Noritake Itron CP2067A VFDs?
 

Offline omegaone

  • Contributor
  • Posts: 36
  • Country: ca
  • eV = 1 Joule / 1 Coulomb
Re: Fluke 8842A Relay K301/K401
« Reply #3 on: November 01, 2018, 07:16:55 am »
Best person to query would be Ordinaryman1971. He helped me procure 8842A VFD.

All the best!
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf