Cockpit

* User Profile

Welcome, Guest. Please login or register.

Login with username, password and session length

Who's Online

  • *Users: 0
  • *Guests: 73
  • *Total: 73

Our Discord

Author Topic: Ground loop gremlins  (Read 420 times)

Offline fsaviator

  • I am chained to this website!
  • *
  • Posts: 1,362
  • Aviation Enthusiast
    • Boeing 737 Next Generation Simulator
  • First Name: Warren
  • Home Location: Riverview, Florida
Ground loop gremlins
« on: October 08, 2018, 12:46:25 PM »
Hey everyone...  need some help here.  I'm at a standstill until I figure this out - I apologize for the lengthy post but you'll see I had little choice.

I've spent two days trying to isolate what appears to be a ground loop that I noticed when I leaned against my TQ and pedestal.  The annunciators in my firepanel would flicker...  took a bit but figured out the TQ side panel had rubbed paint off and was touching the CDU bay in the front, and pedestal in the back

After much searching I determined that the CPFlight five pin cable going to the pedestal was grounding out to the frame somewhere.

More digging and I isolated it to my CPFLight MCP, and finally after more searching to the serial connection on the MCP.  Apparently one of the pins in the RS232 connector grounds out to the frame! 

The serial cable is connected to USB to serial cable connected to my Main PC WHICH IS OFF.  When I remove the USB from the computer, the ground loop is gone.

Now here is where I need help...

I removed all the connections from the PC to the sim... no cables from the PC to any part of the Sim or even visuals..  only the Power cable and the USB to serial adapter and there is still a ground loop, even when the PC is off.  Unplug the PC and the ground loop is gone.

I assume there must be a short elsewhere, and I should now start unplugging power cables connected to the same circuit to isolate the item then trace down the short?

Thoughts?

I'm so close to being up and flying and now I'm bogged down in this, but I know if I don't fix this, I'll have gremlins loose driving me crazy.
Warren "MTN385"
Florida

http://www.B737NG-SIM.com and https://www.facebook.com/fsaviator on facebook
FSX, Prosim737 Suite, FDS DSTD 2.0 MIP, RevSim Proline TQ, ACE Dual-linked Yokes, Intel 3.5GHz i7-3770K, MSI Z77A-G45, 16GB G.Skill TridentX DDR3-2400, Galaxy GTX670 GC 4GB, OCZ 60GB Vertex 3

Offline fsaviator

  • I am chained to this website!
  • *
  • Posts: 1,362
  • Aviation Enthusiast
    • Boeing 737 Next Generation Simulator
  • First Name: Warren
  • Home Location: Riverview, Florida
[SOLVED] Ground loop gremlins
« Reply #1 on: October 08, 2018, 03:01:02 PM »
I traced the issue down to my MIP power supply.  It's an ATX PS that I modified with terminal blocks to provide +5VDC and +12VDC to my fuse blocks.  As soon as I pulled that out, my frame and PC are no longer "connected".  I wonder if it was because I had it mounted in the shell...

Got it connected back up outside the shell and the issue was resolved.  Just to confirm, I ran a jumper from the ATX PS housing to frame, and the problem was recreated....  the frame and PC were once again "connected", through a USB Hub powered by the PS (which was connected to the PC).

Am I making a big deal of nothing?  I guess once I get everything back together we'll find out if the flickering lights in the Fire panel persist.
Warren "MTN385"
Florida

http://www.B737NG-SIM.com and https://www.facebook.com/fsaviator on facebook
FSX, Prosim737 Suite, FDS DSTD 2.0 MIP, RevSim Proline TQ, ACE Dual-linked Yokes, Intel 3.5GHz i7-3770K, MSI Z77A-G45, 16GB G.Skill TridentX DDR3-2400, Galaxy GTX670 GC 4GB, OCZ 60GB Vertex 3

Offline Trevor Hale

  • Administrator
  • I am chained to this website!
  • *
  • Posts: 3,838
    • Cockpitbuilders.com
  • First Name: Trevor
  • Home Location: New Liskeard, Ontario
Re: Ground loop gremlins
« Reply #2 on: October 08, 2018, 04:49:40 PM »
Great Find warren.  Sometimes these things arent big deals, until they become one.  Glad you found it.
Bob had something similar once, his landing gear would deploy randomly that was a problem LOL.
Trev
Trevor Hale

Owner
http://www.cockpitbuilders.com

Director of Operations
Worldflight Team USA
http://www.worldflightusa.com

VATSIM:

 

FlightSimExpo 2019

FsExpo

COUNTDOWN TO WF2019


WORLDFLIGHT TEAM USA

Will Depart in...

Recent Posts

Prosim737 Ver 2 license for sale
by 757Simulator
[Today at 03:27:53 AM]
International shipping?
by navymustang
[June 26, 2019, 08:49:25 PM]
Flooring Installed!
by jackpilot
[June 25, 2019, 05:49:57 PM]
How much room between center pedestal and seat?
by jackpilot
[June 25, 2019, 08:19:42 AM]
PM MCP.ini Question...
by ScottThePilot
[June 25, 2019, 03:14:37 AM]
2020 Microsoft Flight Simulator - new at E3 2019
by blueskydriver
[June 24, 2019, 02:29:16 PM]
How to install DZUS fasteners?
by Buster99
[June 22, 2019, 04:12:34 PM]
Desert Air Spares - Trustworthy?
by kattz
[June 22, 2019, 12:40:51 PM]
Wanted - 737 Audio Panels - OEM
by jackpilot
[June 20, 2019, 12:26:51 PM]
Throttletek 737 Throttle For Sale
by kevinsayre
[June 19, 2019, 03:57:33 PM]
For sale - rudder pedals and linkages - pending to Craig
by Caflyt
[June 19, 2019, 07:49:14 AM]
737-800 Arduino X-Plane Build
by kurt-olsson
[June 18, 2019, 11:26:12 AM]
737 Throttle Conversion OC + ProSim
by kattz
[June 16, 2019, 11:39:03 AM]
A friendly FYI on Boeing rudder pedals
by kattz
[June 15, 2019, 10:36:39 AM]
737 starter switch mechanism
by paulnd
[June 13, 2019, 02:58:39 PM]
Make up your mind, Microsoft!
by jmlohrenz
[June 12, 2019, 07:25:10 PM]
What have you done for your simulator today?
by C150DIY
[June 12, 2019, 12:53:27 PM]
Complete 737-800 cockpit - moving sale
by FaustoP
[June 12, 2019, 01:26:39 AM]
Flyengravity desktop MIP
by patiju
[June 10, 2019, 01:01:06 PM]
the perfect thing to complete your sim hanger
by fsaviator
[June 09, 2019, 03:12:50 PM]
Wanted - COMPLETE set of Boeing 727 or 737 rudder pedals
by kattz
[June 08, 2019, 01:26:09 PM]
Visual system screen by Northern Flight Sim for sale $500
by peterkwu
[June 08, 2019, 06:07:39 AM]
Wanted: GoFlight T8
by C150DIY
[June 07, 2019, 02:32:29 PM]
For Sale - CPFlight MCP737 + EFIS
by ZillaUK
[June 07, 2019, 09:54:58 AM]
737 FWD Overhead Switch Diagram
by bernard S
[June 07, 2019, 08:21:46 AM]
Change the Forum Theme to suit your own Needs.
by AdamMilstead
[June 07, 2019, 06:20:41 AM]
Aileron & Elevator jump back to center
by iwik
[June 06, 2019, 08:01:24 PM]
Join me on Vatsim Tonight
by Trevor Hale
[June 05, 2019, 05:17:13 PM]
Machinery for home cockpit building
by giaviv
[June 04, 2019, 04:12:10 PM]
PROMOCION STEERING FREE
by alvaro castillo
[June 04, 2019, 11:42:43 AM]