Hello all, I recently acquired a non-functioning DX100. It powers up briefly for few seconds and doesn't respond to any buttons on front door. I cleaned the beneath of the buttons with IPA. I also found out that the two tape type sensors are missing the white parts which goes down when cassette is inserted. There's a third sensor as well near the head which is a round like plastic switch, very thin and it goes inside when pressed. I believe this round switch near the head must be damaged or oxidized internally. I tried to clean it with IPA but still doesn't work. Will anyone please suggest how to short out this switch at the board internally to bypass the cassette detection switch near the head. I have been stuck at this stage to get the Walkman to function at least at basic level.
Hi @Valentin , I have started this new thread as you requested. Please do let me know if any workaround is possible to fix this issue.
I presume the walkman does work only with a remote based on your description. If that is the case, it means IC701 is working fine and problem is related to the buttons themselves, hold swtich (always open) or a flex cable. For cleaning I suggest using Kontakt 60/Deoxit or other solution designed for cleaning switches/potentiometers. Fact it stops after a few seconds is more likely to be related to reel rotation detection rather than swtiches. Would check PH701, especially if the infrared LED is turning on (you can do that with a phone camera) and the gear with black/reflective pattern is actually rotating during operation. Given the unit does start and tape in + EQ switches are missing, would assume the tape in swtich is already bypassed (always closed). Otherwise it won't start at all regardless of remote/buttons on unit. The third swich near the head is an A/B switch (detects which side of the cassette is up) and it's not critical to the operation. Meaning the unit will work without it, just that it won't indicate A/B correctly. So no need to bypass this swtich, it's not your problem as it's not a tape detect switch.
Hi @Valentin , regret to inform that I have unfortunately broken the flex cable connecting the side switches while inspecting the device. Also, there was a green LED light when the unit powered up for initial few seconds. (Refer red circles in attached image). The gear with black/reflective patten is rotating for a second. I have also cleaned the buttons completely on the front door. Not sure how to move ahead from here. fixing the flex cable is really tough job.
The LED is voltage reference for the DC-DC converter. To eliminate tape detct swtich as a potential culprit, you need to make S903 - 1 permanently closed (base of Q706 pulled to GND via R723). And as stated before would check the photo detector. As far as the flex cable goes, you'll have to fix it, don't think you will find a replacement for that unless you design and manufacture one yourself.
