Stentofon MPC52 - 720 / Vingtor Marine VMP52 - 120 , a widely used intercom system.

Outranged in 1992, the factory production of service boards stopped in dec. 2002.  But this high quality system is still repairable .

Stations without display only. Connected to AB board .

Stations with or without display .  Connected to ABD board.  

To avoid unlogic behaviour and blown boards, all voltages inside the exchange must float measured to electrical GND . Voltages are easy to measure at the power supply terminals.


Have regular heath control of the exchange:

Make shure all fans are operating, inlet air filters are cleaned / replaced, air outlets are open.


NOTE! 10 years service interval of user program  & backup circuitry.

PMC, PMD, PMF, PMFR , AMC ( service interval: inside every 10th. year, due to limited backup battery life time ) .

We also need a copy of your programming journal or other backup.
PMC, PMD have no EEPROM program storage and need extra precaution.

Shipping with DHL directly to the ship's agent 1 week before ETA.    
The board must be installed in the exchange to be recharged  inside 2 weeks after shipping date, 
After 4 weeks the NiCad backup battery is totally discharged and the program lost.  


If a programming backup on PC or paper is missing: General programming preparation , what must be known before programming . Sorting out what's inside the exchange : Version of running
software on the proccessor board., standard boards / extra function boards,
internal wireing schematic to local terminal numbers .

What's connected to the exchange : stations , stations catalog
number , remote equipment and other hardware connected ,  ref. to terminal
numbers inside  the exchange .


NOTE !   If the exchange is not properly working
pushing the green programming button
on the PMC/PMD/PMF board will alter your customer
specified baud rate programming. This make no sense if you want to repair
the exchange. 

The programming :

This part  is best solved
 a trained programmer combining the use of a pc with different
programming and logging tools, and a programming panel . If handshake circuits
is missing , just add it . And the software has to be replaced to
corresponding handshake software . The PMD ver. Lxx or 2.2 allready
have handshake enabled .

Using a  programming panel :  Make direct addressed
programming by entering line numbers in different system tables and at these
addresses write 16bit - 4 letter hex code with special meaning . Parts
of the exchanges programming are available only by using this programming
panel .  To make meaningful programming it's a must to have good knowledge
in system software organization and hardware functions .

Programming from a station. Easy programming of catalog numbers
for one type of stations, but only a little part of the total programming
is available.

We'll do the programming : Send us the PMD/PMC board , the program
journal and a list of  wanted program changes . We'll program it and
return the board w/ a new backup battery installed .  


Program security

Important reading.


The most important

Note! Power
OFF when plugging !

Like replacing boards in a computer ,  to avoid  serious damage
on the exchange electronic boards
turn off
 the power before replacing any board
in the exchange !!

The printed circuit board of the AB-board ( 61019 ) with surface
mounted micro-components acts like a heatsink and some dark marks tells us
about high temperatures on the PCB surface. Dried out electrolytic capacitors
 is a common problem .  A service tip  : Lift all
electrolytic capacitors  to avoid direct contact with the hot PCB surface
, then the AB-boards will work properly several times longer .    

If hotplugged the 61019 AB board will be damaged
 ( normally beyond repair ), also expect damage on other AB / CLM boards

About CLM boards : Mostly
minor faults . Obsolete, but repairable . A
typical problem  >  Only a low beep while pressing a numeric
button on a station  > No connection .  Or if one or more Ab-boards
has been "hotplugged" also the CLM board may
crash , noise only while pressing a numeric button is a typical symptom .

About DCB / DPB boards: The nonvolatile
sram programming of this board is not an easy task ,  it's smart to
have all DCB / DPB programming written down  in a programming journal

If the DCB / DPB program is all lost , in most cases a trained expert must
examine the excange ,  the DCB / DPB connections and software to compose
a new programming .

Lifetime of the Lithium backup battery  on the DCB / DPB board is 10
years and  it must be replaced while the DCB / DPB board is still working
!   Look for the production year & week , written or stamped on
the lithium battery .

If battery is old send  us the DCB / DPB board to make a complete data
backup , before any attempt to replace this old lithium cell . Do not replace
this battery yourself , the programming will be lost !

Some parts are obsolete , like the TMS9902 circuit .

About FFT boards : Mostly minor faults
. Obsolete, but repairable . Ask us .

About FLX / LEX / LUX : Mostly minor
faults . Some obsolete
Ask us .

About PMI boards : No  problems
or faults . Some hot areas , resistors should be lifted to avoid damage to
the PCB .

About PWR supplies : Overheating , fans are not working , dried out capacitors , noicy
stations , unstable exchange function .  Note!
 Some Vingtor VMP52 / VMP120  PWR 's  have no
+5VDC overvoltage protection !

About SB boards: No  problems
or faults . Some hot areas , resistors should be lifted to avoid damage to
the PCB .

About SB4 boards: No problems or
faults . Fix Xtal to the Printed Circuit Board ( PCB) surface.

About SCE boards: Minor problems.
Fix Xtal to the Printed Circuit Board ( PCB) surface. Some parts are obsolete
, like the TMS9902 circuit .


Standard Ships equipment, on bridge center console.

Emergency microphone VMP 501 / VMP 601

Connected to command input - 100V line amplifiers / command relay alarm bells

Will override alarms, intercom and alarm bells

Alarm Generator user panel.

Extra emergency microphones


Voltages  measured inside a Stentofon MPC / Compact
 or  Vingtor Marine VMP exchange
must be floating , referred to mains ground . Measured
voltage must roll towards zero . External components " like a telephone
interface " often cause a voltage ref. problem .

Jo Tech Service specialities :  some new / improved  station functions are available with these systems.

Example: pa router ( MPC / VMP 52 - 120 )


Non volatile multi message hardware : chipcorder

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