ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Can someone measure the ac voltages of the main transformer unconnected from the power supply? the 0.15ohm resistor right after the transformer was blown so I want to check that the transformer is intact.
Yiangos
I would measure if there isn't a shortcircuit behind the resistor (I think there is not, or a possible capacitor is shortning the circuit). Just replace the resisitor. If there would be a problem in the transformer, then a) the resistor wouldn't have blown and b) will not produce a higher voltage then expected (if for instance several windings are melted).
You could use a variac to turn up the AC voltage slowly, or use a lightbulb in series with the BC5000.
If I remember correctly, this resistor is a flame-proof type.Don't fit anything else.
Martin
Done that, 5 volt rail is back alive :) Thank you guys
drawer opens but the tape mechanism seems wrong, i put a tape but it does not turn a small silver pin is turning tho continuously.
any ideas?
Ok so the problem seems to be that the heads do not move forward to lock on the tape. The tape is detected, as when i put it in the motor starts spinning but thats about it. any idea what else can i check?
Have you checked the belts ?Can you tell if the capstan is rotating ?Will it wind and rewind ?
belts are ok, capstan is turning but no wind or rewind
The tape is not "loading", the heads do not move into place
Sounds as if the belts are not on correctly.Check the path of the square belt below decks.It should be driven by the motor pulley (- not just pass it on both sides).
belt path seems correct, the solenoids are not engaging i think, when i press play i get for 1 second 7v across the play relay but i dont hear or see it move. I will try to manually apply a voltage and see if it moves. btw i get 170ohms resistance on it
Update: I have Dissasemble the tape mechanism and relubricated everything ( i suspected that it might be too much friction). Saddly it has no worked
Can anyone measure the require voltage for the solenoids to work, I think thats the problem.
Can you provide a photo of the underside of the drive?
I have attached a picture. If the belts are correct I have found the problem. TR13(bd136) its base - emitter does not conduct resulting in only 7 volts for the relay instead of 16 (24v reference). I will order some and give it a try
And the tapes load perfectly now:)
Onto the next issue, PPM. Should it light up during playback? or it only happens during recording?
If it should during playback, mine is dead. Any common parts to check?
Update: She is all fixed up now, it was a dead 4011 chip:)