T-View 100 » History » Version 10
manawyrm, 03/09/2022 11:27 PM
1 | 1 | manawyrm | h1. T-View 100 |
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3 | 3 | manawyrm | T-View 100 was a video telephone, made by Deutsche Telekom / Siemens. |
4 | 1 | manawyrm | |
5 | 6 | manawyrm | @manawyrm has two of these phones, @LaForge owns one as well. |
6 | |||
7 | 5 | manawyrm | h2. External photos |
8 | 9 | manawyrm | !{width:40%}DSC00422.jpg! !{width:40%}DSC00423.jpg! |
9 | 5 | manawyrm | |
10 | Power supply is called STN20, output DC 22.5V; 0.9A. Center positive, 5.5/2.5mm barrel jack. |
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11 | The RCA connectors are (from left to right): Audio out, Video out, Video in, Audio in |
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12 | 10 | manawyrm | |
13 | h3. Mini-DIN / RS232 |
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14 | |||
15 | The Mini-DIN (8pin) connector carries a RS232 serial. It was used to connect to auxiliary devices like relay control boxes (to alert blind people of calls), VCRs (remote control) and PCs (for firmware updates). |
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16 | No such firmware update software is preserved. If you own a copy, please upload it! |
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17 | |||
18 | 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. |
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19 | |||
20 | |_.Mini-DIN|_.RS232|_.RS232 Pin| |
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21 | | 1 | NC | - | |
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22 | | 2 | TXD | 3 | |
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23 | | 3 | RXD | 2 | |
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24 | | 4 | RTS | 7 | |
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25 | | 5 | CTS | 8 | |
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26 | | 6 | NC | - | |
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27 | | 7 | GND | 5 | |
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28 | | 8 | NC | - | |
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29 | 5 | manawyrm | |
30 | h2. Internal photos |
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31 | 3 | manawyrm | |
32 | Video/Interfacing PCB: |
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33 | !{width:40%}IMG_3633.JPG! |
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34 | |||
35 | Telephone PCB: |
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36 | !{width:40%}IMG_3644.JPG! |
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37 | |||
38 | Display/Camera PCB: |
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39 | !{width:40%}IMG_3656.JPG! |
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40 | |||
41 | h2. Phone disassembly |
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42 | 1 | manawyrm | |
43 | 6 | manawyrm | The bottom cover plate has 6 Phillips screws and is clipped together at the bottom. Use multiple guitar picks to get them free. |
44 | 2 | manawyrm | The plastic does not seem to be brittle (yet), some force is OK. |
45 | |||
46 | 1 | manawyrm | !{width:40%}IMG_3647.JPG! |
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48 | Backside of the main video / interfacing PCB is visible under the cover plate: |
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49 | !{width:40%}IMG_3631.JPG! |
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50 | |||
51 | 3 | manawyrm | Lift the video / interfacing PCB out by pulling it straight up, it's connected via a rigid interface PCB (but not screwed down): |
52 | 1 | manawyrm | !{width:40%}IMG_3634.JPG! |
53 | 3 | manawyrm | |
54 | 6 | manawyrm | Unscrew the 7 Phillips screws attaching the plastic shield. Be careful with the speaker wires on the right, they are not detachable! |
55 | 3 | manawyrm | 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. |
56 | !{width:40%}IMG_3642.JPG! |
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57 | 4 | manawyrm | |
58 | h2. Display/camera disassembly |
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59 | |||
60 | Disassembling the display/camera unit is a bit tricky. You'll need a 10mm socket (and possibly socket extension)! |
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61 | |||
62 | Start by removing the 4 screws on the connector: |
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63 | !{width:40%}IMG_3650.JPG! |
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64 | |||
65 | then remove the 3 screws in the top of the unit. |
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66 | The sides of the display/camera unit are covered with round covers. They can be pulled out with a bit of force. |
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67 | !{width:40%}IMG_3652.JPG! |
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68 | |||
69 | 1 | manawyrm | Use a 10mm socket to unscrew the nuts on both sides. |
70 | 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: |
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71 | !{width:40%}IMG_3653.JPG! |
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72 | |||
73 | Remove both bolts (and the washers). The swivel piece can now be bent inwards slightly with a bit of force to get it out. |
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74 | !{width:40%}IMG_3654.JPG! |
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75 | Unscrew the 2 remaining screws holding the display unit together. |
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76 | |||
77 | There are clips all around the display/camera unit. Use guitar picks again and open the display. |
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78 | 7 | manawyrm | |
79 | h2. Common faults |
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80 | |||
81 | - Faulty display hotbar |
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82 | Symptoms: Missing (pixel) rows / columns on the (24x2) character LCD. |
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83 | Fix: Try and reheat the hotbar (~180°C) with a clean soldering iron tip and a lot of pressure |
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84 | |||
85 | Symptoms: Garbled characters/stuck bit |
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86 | Fix: HD44780 interface is connected via Hotbar as well. |
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87 | Find out which bits (D0-D7) are affected and solder wires for those bits directly to the LCD |
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88 | !{width:40%}IMG_3779.JPG! |
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89 | |||
90 | - Faulty capacitors |
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91 | Symptoms: Crashing, low display contrast, flickering LEDs, poor video quality, mains hum on the speakers |
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92 | Fix: Replace all electrolytic capacitors |
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93 | |||
94 | 8 | manawyrm | Remove the old caps using the "Twist method":https://www.youtube.com/watch?v=-1S3F6_g3Sw |
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96 | 7 | manawyrm | |_.Capacity|_.Voltage|_.Count|_.Width x Height (mm)|_.Replacement part| |
97 | |220µF|35V|8|10.31x10.31|Nichicon UCL1V221MCL6GS| |
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98 | |470µF|16V|2|10.31x10.31|Nichicon UCX1C471MCL1GS| |
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99 | |47µF|35V|6|8.28x8.28|Nichicon UUE1V470MNS1GS| |
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100 | |220µF|10V|1|8.28x8.28|Nichicon UWG1A221MNL1GS| |
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101 | |47µF|16V|3|6.60x6.60|Nichicon UCB1C470MCL1GS| |
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102 | |100µF|10V|1|6.60x6.60|Nichicon UUT1A101MCL1GS| |
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103 | |2.2µF|35V|2|3.33x3.33|Nichicon UWJ1H2R2MCL1GB| |
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104 | |10µF|16V|1|3.33x3.33|Nichicon UUT1C100MCL1GS| |
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105 | 8 | manawyrm | |
106 | - Bad connections |
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107 | Symptoms: Phone working, no picture, no backlight |
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108 | Fix: Replug the display assembly a couple of times |
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109 | 7 | manawyrm | |
110 | - ??? |
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111 | Symptoms: Nothing, black screen, no LEDs, ~500mA current draw |
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112 | Fix: ??? |