Door King 1830-01 POTS telephone hum prevents data send/receive.

[fred3]

We have a Door King 1830-01 which uses Plain Old Telephone system (POTS) communication for data in addition to telephone calls to residences from the controller. The telephone line is clean but, when connected to the 1830-01, there is a fairly strong 60Hz hum on the line.
The telephone company tested the phone line on site and found no troublel with it. We did the same today and confirmed that the line (at the connection to the 1830-01 is without the hum. But, when the 1830-01 goes "off hook", the hum is evident. So, we blame the main board - which is really the only board of significance.
Has anyone seen this? Does anyone know of a fix? We are capable of dealing with the electronics and the board in replacing components We just don't know where to start.

Thank you!!

 

[Martaine2005]

Sounds like a power supply issue or even dirty connections.
Filter caps would be my first suspicion, but I don’t know if the unit is line (tel) powered or mains powered.
Check the GROUND connections too, as often these deteriorate/oxidise on external metal/clad housings.

Martin

 

[Delta Prime]

Hello there!

DoorKing 1830-142 Isolation Transformer

• Reduce or Eliminate Noise From Troublesome Phone Lines • Use with 1834, 1835, 1837 • Installation within TES Housing Recommended • All Products Require a 3-5 Day Lead Time

gatedepot.com

 

[Delta Prime]

Hello there!

DoorKing 1830-142 Isolation Transformer

• Reduce or Eliminate Noise From Troublesome Phone Lines • Use with 1834, 1835, 1837 • Installation within TES Housing Recommended • All Products Require a 3-5 Day Lead Time

gatedepot.com

Use only as reference please.
Shop around.

 

[73's de Edd]

Sir fred3 . . . . .

BEFORE blowing an exploratory $80.00 + pig-in-a-poke ?
(Plus there is a CHEAPER alternative for that isolation transformer if . . .IF . . . IF even needed

PLUS initially troubleshoot . . .thusly . . . . .

CHECK YOUR UNIT FOR THESE COMPARATIVE ASPECTS . . . . .

Photo 1
RED ARROW Item 1's of which, one may be the diamond shaped TO-3 encased 3 terminal regulator
and its like shaped heat sink. And this photo seems to suggest of a TO-220 shaped 3 terminal plastic 3 terminal regulator and its rectangular shaped companion heat sink .

RED ARROW item 2's blue cased AXIAL main electroltytic capacitor.

Examine the markings on all items . . . . . of particular interest will be a 7812 or 7815 on the far left regulator and possibly a 7805 on the right regulator.

The item 2 will have a capacitance and DC working voltage identification.
Also look at the right top corner for the 2 companion RADIAL leaded E-capacitors for their voltage rating and capacitances.

Move down to the Photo 4 and see the possible alternate use of a second TO-3 ( BOTH RED CIRCLED)and thus, the vacancy of the second previously pointed out plastic TO-220 at the top.

Look to bottom right corner and get that 3 terminal plastic TO-220 numbering and also the 4 o clock positioned RADIAL E- cap's voltage and capacitances..


MOVE TO PHOTO 2 . . . . .

See if they used / incorporated either phone line and or power line suppressors . . .within 10 ft of your unit.

The ferrite filter blocks shown down at the bottom mainly have to do with any STRONG nearby AM radio station coming in on the background.


GROUNDING
Look at my Photo 1 GREEN SQUARE of the unit ground wire to case and then to Photo 3 and its connection into terminal block #3.

MAKEE -MAKEE- TESTEE- TESTEE

Get your unit making its nasty noise and take the ground wire loose from board terminal 3.
Does the problem change ? then listen while you put it back into connection with terminal 3. . . . . . any change ?
If satisfied, of no problem, reconnect to #3 and tighten along with its other ends terminal and its screw, along with its biting in lock washer . . . . . . to be TIGHTENED.

Initially, take note or mark each of the incoming phone wires on terms 1 and 2 and then remove to see if the offending noise still is present ? ? ?

If so, we are then suspect of the 1830 board, so that is why the collecting of the data on the regulators and their related E caps .

Thaaaaaaaaaaaasssit . . . . . . . now talk some technicalese to me . . . . . babe . . . . .

MAGNIFICENT TECHNO PHOTOGRAPHIC REFERENCING . . . . .



(also Hosted) at

https://i.ibb.co/MNY3HYd/DOORKING-1830-UNIT.png

(Or the WHOLE fuchbuk is @

https://doorking.com/sites/default/files/downloads/1835-065-D-5-17.pdf

73's de Edd . . . . .


Conserve Toilet Paper ! . . . wipe with both sides of the sheet.

https://media.tenor.com/images/3ae0cf699fbaff26ad74d5755d0b8a63/tenor.gif

 

[Delta Prime]

I like this guy Definitely.NASA. Need Another Space Astronaut.

 

[bidrohini]

You can also contact Doorking support team: https://www.doorking.com/tech-support