How to change the cassette deck belts on the Panasonic RX-DT707 "Cobra Top" from early 1990's? I ordered the replacement belts from Thakker e-bay store. The set includes 4 belts, 2 for each deck. Cost as of May 2024 is $19.50US + shipping. Webspareparts also sells the belts sourced from Germany. As does DechTech on e-bay. Are they all sourced from the same manufacturer? Probably. The belts consist of a large flat belt and a smaller round belt. This small round belt is, instead of round, square, in the replacement package I got from Thakker. This is a basic quick overview to help those who are looking to see what it takes to replace the belts. Make sure to have a quality synthetic oil for lubricating the bearings, motor and capstans at the same time. (I developed the habit of using gloves so as not to add skin oils to new belts when working on anything like this. Also useful as one can clean hands from accidental grease contamination with alcohol or cleaners periodically throughout the process.) Remove the 8 long screws. All 8 are the same length. The 2 on the handle once removed will allow the handle to come off. I found an old credit card to be a good tool to open the case. There are no wires connecting to the speakers. Instead there is a connector with pins. Remove the 6 screws holding the combo deck. The deck then simply lifts up as it has electrical connectors. No wiring to de-solder. The decks come out like a cartridge. Very convenient. Both deck units are connected with a white plastic bridge. 3 screws hold the top plate with motor. With screws removed this plate is still held in place with raised screw post stand off's. Nice. Just lift off slowly and the belt will come away too. Lift away the top plate with motor and the belt comes away too. Removing the old round belt. Other replacement belt packages may use a round belt? It should be a round belt not a square belt in my opinion. Intensive cleaning with cotton tip and 70% alcohol of the belt path pulleys. Remove all old black rubber residue. Critically important step! Go slow. Make sure to clean this pulley too. Carefully. Form cotton swap end with pliers then moisten with alcohol. This way the cotton is shaped to fit into the groove. Old belts kept. Deck 01 belt had very low W&F measurement. Better then the new belts. I was questioning whether to put the old ones back in for deck o1. (Deck 02 belts were degraded and poorer W&F. New belts improved W&F a lot). 4 conductor ribbon cable to motors. PCB has hole through. Use solder pump to clear holes and clean up pads. Maybe to install a 4-pin connector would be a good idea for solder free removal? I would like to so that just for the sake of it... Motor speed adjustment procedure is detailed in the Service Manual on pages 50 / 51 (Google for service manual which is freely available as a .pdf file). I did a lot of different WFGUI tests and stop / start / rewind etc., and the new belts are still settling in. EDIT: to add pieces of the service manual with speed adjust: Will re-test again after some hours of play time. Basic quick preliminary results as follows: Deck 02 test results WFGUI and test tape 3150hz 3140.6 0.1023 0.1985 3140.9 0.1245 0.2803 3140.6 0.1431 0.2803 3141.7 0.1132 0.2803 3141.3 0.1496 0.2849 3140.6 0.1294 0.2885 3140.9 0.1062 0.2885 3140.0 0.1462 0.2885 3141.1 0.1115 0.2885 3140.5 0.1510 0.2885 3139.7 0.1064 0.2885 3140.0 0.1116 0.2885 3140.5 0.1520 0.2885 3140.1 0.1174 0.2885 3141.2 0.1437 0.2885 3140.9 0.1316 0.2769 3140.8 0.1113 0.2769 3140.3 0.1280 0.2779 3140.7 0.1218 0.2779 3140.3 0.1248 0.2779 3139.9 0.1280 0.2779 3140.8 0.1320 0.2779 3140.4 0.1317 0.2779 3139.9 0.1044 0.2779 3140.8 0.1360 0.2779 3139.9 0.1358 0.2779 3140.4 0.1113 0.2779 3140.3 0.1280 0.2686 3139.6 0.1107 0.2686 3140.5 0.1535 0.2918 3140.3 0.1617 0.3008 3139.6 0.1314 0.3008 3140.4 0.1488 0.3008 3139.8 0.1367 0.3008 3140.8 0.1268 0.3095 3140.0 0.1182 0.3095 3139.5 0.0950 0.3095 3139.9 0.1397 0.3095 3140.0 0.1505 0.3095 3140.0 0.1013 0.3095 Deck 02 test results WFGUI and test tape 3000hz: 2986.6 0.1166 0.2004 2986.0 0.1079 0.2021 2986.2 0.1067 0.2021 2985.5 0.1058 0.2021 2986.0 0.1064 0.2345 2985.6 0.1103 0.2345 2984.9 0.1168 0.2429 2985.4 0.1022 0.2429 2984.8 0.1266 0.2429 2984.9 0.1126 0.2429 2984.1 0.1067 0.2429 2983.9 0.1100 0.2429 2983.8 0.1165 0.2429 2983.8 0.1182 0.2429 2983.5 0.1000 0.2429 2983.4 0.1146 0.2429 2981.8 0.1169 0.2346 2982.9 0.1087 0.2346 2981.4 0.1277 0.2379 2982.3 0.0991 0.2379 2981.2 0.1138 0.2503 2980.7 0.1289 0.2503 2980.8 0.1050 0.2503 2980.1 0.1133 0.2503 2980.6 0.1130 0.2503 2979.8 0.1088 0.2503 2979.6 0.1173 0.2503
