ethyrvalve
Norman Nanoweber
Hi all,
I'm looking at someone's B-16 right now. Its supply reel spins at full speed/power (clockwise) as soon as it's powered on. The tension arms and transport buttons have no effect on it.
When I trick the tape end sensor and tension arms into thinking tape is loaded I can make the transport functions work for the capstan, pinch roller and takeup reel motor. With the supply reel motor transistor connector unplugged, it pretty much works like a normal tape machine (except that it obviously can't rewind). I can even see that the supply reel's brake is working (disengaging for play/fast wind).
The owner told things gradually started acting funny and it was only when I first looked at it that it started going haywire.
I already replaced the motor drive transistor and it didn't fix the issue.
All the PSU voltages test very close to the schematic values except the +26v rail (which is used for the reel motors) measures about +29v. About a year ago, another tech recapped the power supply, replaced a diode bridge and also replaced that same motor transistor. The components match the schematic except he did slightly downrate a 3300µF cap to 3000µF.
Just wondering if anyone has any experience with these machines and/or clues?
Thanks!
I'm looking at someone's B-16 right now. Its supply reel spins at full speed/power (clockwise) as soon as it's powered on. The tension arms and transport buttons have no effect on it.
When I trick the tape end sensor and tension arms into thinking tape is loaded I can make the transport functions work for the capstan, pinch roller and takeup reel motor. With the supply reel motor transistor connector unplugged, it pretty much works like a normal tape machine (except that it obviously can't rewind). I can even see that the supply reel's brake is working (disengaging for play/fast wind).
The owner told things gradually started acting funny and it was only when I first looked at it that it started going haywire.
I already replaced the motor drive transistor and it didn't fix the issue.
All the PSU voltages test very close to the schematic values except the +26v rail (which is used for the reel motors) measures about +29v. About a year ago, another tech recapped the power supply, replaced a diode bridge and also replaced that same motor transistor. The components match the schematic except he did slightly downrate a 3300µF cap to 3000µF.
Just wondering if anyone has any experience with these machines and/or clues?
Thanks!