T-View 100 » History » Revision 48

« Previous | Revision 48/51 (diff) | Next »
manawyrm, 11/24/2022 05:46 PM

T-View 100

T-View 100 was a video telephone, made by Deutsche Telekom / Siemens.

manawyrm has five of these phones, laforge owns two as well.

External photos

DSC00422.jpg DSC00423.jpg

Power supply is called STN20, output DC 22.5V; 0.9A. Center positive, 5.5/2.5mm barrel jack.
The RCA connectors are (from left to right): Audio out, Video out, Video in, Audio in

Mini-DIN / RS232

The Mini-DIN (8pin) connector carries a RS232 serial. It was used to connect to auxiliary devices like relay control boxes (to alert deaf people of calls), VCRs (remote control) and PCs (for firmware updates).
We have a copy of the 1.2 firmware update and the RS232 communication protocol.

RS232 pinout is given without Null-Modem reversal (aka it's meant to be a male connector), reverse RXD/TXD and RTS/CTS for a female connector.
Serial settings (for debug output) seems to be 19200, 8n2.
Mini-DIN RS232 RS232 Pin
1 NC -
2 TXD 3
3 RXD 2
4 RTS 7
5 CTS 8
6 NC -
7 GND 5
8 NC -

The framing and at least some commands are described in V24-Control.pdf

Service menu

There is a hidden service menu. Scroll to "Service", press OK, type the number 7.
Enter passcode "3570" and press OK.

"Service" -> 8 is another hidden option for a "Factory SETUP". The passcode is 3745.

Internal photos / circuit boards

Video/Interfacing PCB


We can see here:
  • Philips SAA 7111 VIP (Video Input Processor) SAA7111.pdf
  • 8x83104AKAB VCP (Video Codec Processor)
    • 4x ISSI IS61C1024-20J 1MBit 128Kx8 SRAM IS61C1024.pdf
    • 2x Siemens HYB514171BJ-70 256Kx16 DRAM
    • AM29F040 4Mbit (512Kx8) Flash AM29F040.pdf
  • Motorola XC68307FG16 XC68307.pdf
    • 2x Epson SRM2B256SLMX70 32Kx8 SRAM
    • AM29F400BB-120C Flash AM29F400B.pdf (label: VCod14)
  • NEC V30145-J4681-V29
  • Siemens PSB7230 JADE (Joint Audio Decoder-Encoder for Videophone) V2.2 PSB7230.pdf
  • NatSemi P78SF MM74HC244
  • Analog Devices ADV7176KS Digital CCIR-601 YCrCb to PAL/NTSC Video Encoder ADV7176KS.pdf

Telephone PCB


The telephone PCB has a debug header with a UART interface on it:


This debug header can be used to supply +5V (~100mA) to the phone board externally.
The phone board will work stand alone and this can be very useful for trouble shooting display issues!


Display/Camera PCB


Phone disassembly

The bottom cover plate has 6 Phillips screws and is clipped together at the bottom. Use multiple guitar picks to get them free.
The plastic does not seem to be brittle (yet), some force is OK.


Backside of the main video / interfacing PCB is visible under the cover plate:


Lift the video / interfacing PCB out by pulling it straight up, it's connected via a rigid interface PCB (but not screwed down):


Unscrew the 7 Phillips screws attaching the plastic shield. Be careful with the speaker wires on the right, they are not detachable!
Lift the plastic shield out of the way to the right. When re-assembling, make sure the hook-mechanism and speaker are correctly in-place.


Display/camera disassembly

Disassembling the display/camera unit is a bit tricky. You'll need a 10mm socket (and possibly socket extension)!

Start by removing the 4 screws on the connector:


then remove the 3 screws in the top of the unit.
The sides of the display/camera unit are covered with round covers. They can be pulled out with a bit of force.


Use a 10mm socket to unscrew the nuts on both sides.
Lift the connector cover. This is tricky! Please fill in a good way to do this. The author broke 2 plastic clips by doing it:


Remove both bolts (and the washers). The swivel piece can now be bent inwards slightly with a bit of force to get it out.


Unscrew the 2 remaining screws holding the display unit together.

There are clips all around the display/camera unit. Use guitar picks again and open the display.

Common faults

Faulty LCD hotbar

Symptoms: Missing (pixel) rows / columns on the (24x2) character LCD.
Fix: Try and reheat the hotbar (~180°C) with a clean soldering iron tip and a lot of pressure

Faulty HD44780 hotbar

Note: The LCD is part of the phone's 68000 CPU bus!
A problem with the HD44780 will keep the whole telephone from working. The phone board won't start and will wait for LCD init. The TFT will stay off, all LEDs will stay off.

Symptoms: Phone not booting at all, no display, no LEDs, completely dead. Current draw ~250mA.
Fix: Check resistance between pins on the HD44780 itself and the phone board. Usually pins like VCC, GND or some of the datapins won't have continuity or more than ~1kOhms.
Run extra wire(s) from the test points (see "Display test point pinout" below) to the 2x8 footprint on the HD44780 LCD itself. Enamelled copper wire works well for this.

You can run the phone board seperately, without the video board. Apply +5V to the debug header as shown above.

Symptoms: Garbled characters/stuck bit
Fix: HD44780 interface is connected via Hotbar as well.
Find out which bits (D0-D7) are affected and solder wires for those bits directly to the LCD

IMG_3779.JPG Bildschirmfoto 2022-03-11 um 13.07.27.png

Faulty display

Symptoms: No LCD output at all
Fix: Buy a new LCD. You'll need one with HD44780 ROM code A00 charset (the Japanese/Kana charset). The 0xE1 character should be "ä" (a with Umlauts).

We couldn't find any mechanically 100% compatible model, but the NewHaven NHD-0224AZ-FSW-GBW is electrically and character set compatible. If you want to do the re-work, the following recommendations apply:
  • remove the transparent plastic carrier for the old LCD module
  • remove the old LCD module (just tear the flex cable from the top side of the board)
  • use solder wires to connect the new LCD to vias on the PCB (see picture)
  • either fix the contrast voltage to GND, or re-work the existing contrast voltage biasing circuit. The original Siemens circuit consists of a 5V PWM feeding into a resistive divider of two 24kOhms resistors. Replace the GND-facing resistor with a 2.2kOms (or even lower). Play with the contrast settings (+/- buttons while receiver is on-hook) to see if you hit the right voltage range. Adjust resistive divider as needed.
  • re-work the plastic cover that is located between the two boards as needed. You can either make more space for the LCD module by creatng a cut-out, or you can use it as-is and adjust the spacers on the "video" side.


Display test point pinout

T-View 100 Display replacement.jpg

Pinout hotbar/flex-cable vs. 2.54mm header


Notes regarding adjusted resistive divider for backlight


Faulty capacitors

Symptoms: Crashing, low display contrast, flickering LEDs, poor video quality, mains hum on the speakers
Fix: Replace all electrolytic capacitors

Remove the old caps using the Twist method

Capacity Voltage Count Width x Height (mm) Replacement part
220µF 35V 8 10.31x10.31 Nichicon UCL1V221MCL6GS
470µF 16V 2 10.31x10.31 Nichicon UCX1C471MCL1GS
47µF 35V 6 8.28x8.28 Nichicon UUE1V470MNS1GS
220µF 10V 1 8.28x8.28 Nichicon UWG1A221MNL1GS
47µF 16V 3 6.60x6.60 Nichicon UCB1C470MCL1GS
100µF 10V 1 6.60x6.60 Nichicon UUT1A101MCL1GS
2.2µF 35V 2 3.33x3.33 Nichicon UWJ1H2R2MCL1GB
10µF 16V 1 3.33x3.33 Nichicon UUT1C100MCL1GS

Bad connections

Symptoms: Phone working, no picture, no backlight
Fix: Replug the display assembly a couple of times

Bootlog (RS232 Debug)

A logfile of the external RS232 connector while booting and making a call can be found here:

External Camera

There was an official external camera accessory , a Deutsche Telekom 663701-001 (re-branded Minolta EDUKCM-100)


manawyrm stumbled across a T-View prototype:

DSC00021.JPG DSC00022.JPG

DSC00023.JPG DSC00024.JPG

DSC00026.JPG DSC00027.JPG

Noticeable differences include:
- Green LEDs (instead of Red LEDs)
- White printing on the connectors (instead of embossed text in the plastic)
- Handset has a magenta T-symbol, instead of the white T-symbol
- HD44780 display is connected via jumper wires (instead of hot bar flat-flex cables)
- ProfiTel70 / Phone board is powered only by S0 bus voltage, not through DC in
- 0.1" pin header populated on the phone board
- handwritten label for firmware flash IC on the phone board
- PLCC socket for firmware flash IC on the video board
- VCP is still manufactured by IIT, later split off into 8x8
- bad mechanical fit (RJ45 latch cannot be accessed without tools, recessed too deep)
- CNC toolmarks are visible in plastic housing (CNC aluminium soft mold was probably used for injection molding)
- generic FRIWO FW 7324/3 24V power supply, instead of the 22.5V STN20 PSU

The broken display was replaced with the new Newhaven type (see above):

IMG_6017.JPG cxyjhtglofw.jpg

VCP (version 4014) dump:


There are four known firmware versions:
Version Release Date Telefon Codec VCP Jade
V1.0 July 1998 ? ? ? ?
V1.1 ? 33 14 4014 2.2
V1.2 December 1998 43 20 4025 2.2
V1.3 ? ? ? ? ?

Telefon/Codec/VCP/Jade firmware versions can be checked in the service menu (see above).

The firmware consists actually of different images for different processors on the unit.

Filename Format Purpose
vcvcp.bin binary presumably for the video codec/processor
vsetrel.abs srec for the VSet (telephone) board, derived from ProfiTel70
vcodrel.abs srec contains strings related to H.261, H.221 and VCP
The Firmware update utility running on the PC side is called Fload68k.exe "M68k Flash-Loader V 3.31 (C) 1997 Orsys GmbH" and it talks about three parts:
  • "Talkset" (abs format, programmed via SPI or "RS232 direct")
  • "VCODEC" (abs format, programmed via via "RS232 direct")
  • "VCP" (bin format, separate programming mode "VCP")
Files (48)
IMG_3661.JPG View IMG_3661.JPG 2.65 MB Display with 24x2 characters manawyrm, 02/18/2022 10:24 PM
IMG_3636.JPG View IMG_3636.JPG 2.7 MB manawyrm, 02/18/2022 10:24 PM
IMG_3652.JPG View IMG_3652.JPG 2.24 MB Round side cover plates removed on the display/camera unit manawyrm, 02/18/2022 10:24 PM
IMG_3656.JPG View IMG_3656.JPG 3.02 MB Display/camera unit PCB manawyrm, 02/18/2022 10:24 PM
IMG_3650.JPG View IMG_3650.JPG 2.41 MB Backside of the display/camera unit manawyrm, 02/18/2022 10:24 PM
IMG_3647.JPG View IMG_3647.JPG 2.43 MB Backside of the T-View 100, cover plate with 6 screws manawyrm, 02/18/2022 10:24 PM
IMG_3642.JPG View IMG_3642.JPG 2.63 MB Cover plate over the telephone PCB with 7 screws manawyrm, 02/18/2022 10:24 PM
IMG_3644.JPG View IMG_3644.JPG 3.61 MB Telephone PCB manawyrm, 02/18/2022 10:24 PM
IMG_3633.JPG View IMG_3633.JPG 3.48 MB Main video / interfacing PCB manawyrm, 02/18/2022 10:24 PM
IMG_3631.jpg View IMG_3631.jpg 4.08 MB View after removing the cover plate, backside of the main video / interfacing PCB manawyrm, 02/18/2022 10:24 PM
IMG_3634.JPG View IMG_3634.JPG 2.63 MB Interconnect PCB between the video/interfacing and telephone PCBs manawyrm, 02/18/2022 10:38 PM
IMG_3653.JPG View IMG_3653.JPG 2.49 MB Interconnect PCB on the bottom of the display/camera unit manawyrm, 02/18/2022 10:50 PM
IMG_3654.JPG View IMG_3654.JPG 2.97 MB Underneath the swivel piece on the display/camera unit manawyrm, 02/18/2022 10:54 PM
IMG_3665.JPG View IMG_3665.JPG 2.63 MB T-View 100 front manawyrm, 02/18/2022 11:01 PM
IMG_3666.JPG View IMG_3666.JPG 2.5 MB T-View 100 back manawyrm, 02/18/2022 11:01 PM
IMG_3779.JPG View IMG_3779.JPG 2.37 MB manawyrm, 03/02/2022 11:41 PM
DSC00422.jpg View DSC00422.jpg 2.95 MB Front view of the T-View 100 manawyrm, 03/05/2022 01:07 PM
DSC00423.jpg View DSC00423.jpg 2.95 MB Back view of the T-View 100 manawyrm, 03/05/2022 01:07 PM
tview_boot_and_call.bin tview_boot_and_call.bin 11.6 KB Binary boot output/log manawyrm, 03/10/2022 12:00 AM
Bildschirmfoto 2022-03-11 um 13.07.27.png View Bildschirmfoto 2022-03-11 um 13.07.27.png 1.17 MB LCD pinout manawyrm, 03/11/2022 12:07 PM
V24-Control.pdf View V24-Control.pdf 722 KB Remote control via V.24 (RS-232) laforge, 03/11/2022 04:28 PM
stecker.pdf View stecker.pdf 336 KB RS232 cable manawyrm, 05/02/2022 10:59 AM
tview-nhd-rework.jpg View tview-nhd-rework.jpg 371 KB laforge, 11/06/2022 09:53 PM
ADV7176KS.pdf View ADV7176KS.pdf 445 KB laforge, 11/10/2022 04:04 PM
SAA7111.pdf View SAA7111.pdf 406 KB laforge, 11/10/2022 04:06 PM
IS61C1024.pdf View IS61C1024.pdf 842 KB laforge, 11/10/2022 04:08 PM
AM29F400B.pdf View AM29F400B.pdf 581 KB laforge, 11/10/2022 04:11 PM
PSB7230.pdf View PSB7230.pdf 2.37 MB laforge, 11/10/2022 04:12 PM
AM29F040.pdf View AM29F040.pdf 269 KB laforge, 11/10/2022 04:18 PM
XC68307.pdf View XC68307.pdf 173 KB laforge, 11/10/2022 04:20 PM
IIT3204 MPPex.pdf View IIT3204 MPPex.pdf 11.6 MB manawyrm, 11/16/2022 05:27 PM
DSC00022.JPG View DSC00022.JPG 14.9 MB T-View prototype video board back manawyrm, 11/18/2022 08:55 PM
DSC00021.JPG View DSC00021.JPG 16.7 MB T-View prototype video board front manawyrm, 11/18/2022 08:55 PM
DSC00024.JPG View DSC00024.JPG 11.4 MB T-View prototype telephone board back manawyrm, 11/18/2022 08:55 PM
DSC00023.JPG View DSC00023.JPG 15.7 MB T-View prototype telephone board front manawyrm, 11/18/2022 08:55 PM
DSC00026.JPG View DSC00026.JPG 6.95 MB T-View prototype case back manawyrm, 11/18/2022 08:55 PM
DSC00027.JPG View DSC00027.JPG 9.03 MB T-View prototype case top manawyrm, 11/18/2022 08:55 PM
IMG_6017.JPG View IMG_6017.JPG 2.44 MB T-View prototype display issues manawyrm, 11/19/2022 01:59 AM
cxyjhtglofw.jpg View cxyjhtglofw.jpg 2.55 MB T-View prototype new display manawyrm, 11/19/2022 01:59 AM
bootlog-v1.2.txt bootlog-v1.2.txt 7.66 KB manawyrm, 11/19/2022 02:06 AM
20221108_220025.jpg View 20221108_220025.jpg 431 KB pinout of hotbar/flex vs. 2.54mm header laforge, 11/19/2022 05:41 PM
20221108_215856.jpg View 20221108_215856.jpg 311 KB Notes regarding adjusted resistive divider for backlight laforge, 11/19/2022 05:42 PM
t-view-prototype_plcc32_firmware_1.1_am29f040_Vcvcp.bin t-view-prototype_plcc32_firmware_1.1_am29f040_Vcvcp.bin 512 KB manawyrm, 11/22/2022 12:45 PM
t-view100-debugheader.jpg View t-view100-debugheader.jpg 203 KB debug header on phone board manawyrm, 11/24/2022 02:09 PM
T-View 100 Display replacement.jpg View T-View 100 Display replacement.jpg 2.23 MB Testpoint pinout for HD44780 text display manawyrm, 11/24/2022 02:42 PM
behxaityrfs.jpg View behxaityrfs.jpg 2.35 MB manawyrm, 11/24/2022 03:58 PM
0009.jpeg View 0009.jpeg 710 KB T-Card B WIMPy, 01/11/2024 02:57 AM
0008.jpeg View 0008.jpeg 2.49 MB T-Card F WIMPy, 01/11/2024 02:57 AM

Updated by manawyrm over 1 year ago · 48 revisions

Add picture from clipboard (Maximum size: 48.8 MB)