Vic 20 cassette drive issues

[bpatte02]

I just recently obtained a Vic 20 and it came with the c2n drive. The computer looks and works great except when I hook up the cassette drive and type load and press play nothing happens. The cassette doesn't move and if I try to fast forward or rewind nothing happens. I thought it was the drive so I got another but no mas, it acts the same. I'm not sure what's wrong and was wondering if any of you guys had any ideas. I have tested to make sure the port is getting power and it is but I'm not sure what each prong is suppose to register. Thanks for any help you can suggest.

[bpatte02]

I think I figured out the issue, the prong c-3 which is the motor is only putting out .10v which can't even make the motor twitch, any idea what might cause that?

[carlsson]

I'll assume you've got a VIC-20CR with the DIN style power connector. Measure the AC line on the power supply, so you've got both 9V AC and 5V DC.

[bpatte02]

my vic-20 uses a 7 pin DIN and i replaced the original power supply with a after market one made by Ray Carlsen after reading up on the potential harm original power supplies can cause. As of right now I'm not sure what else i can do. I did a DC Volt check on the port and it reads as follows:

A-1 - GND

B-2 - 4.97v DC

C-3 - 0.15v DC

D-4 - 0.38v DC

E-5 - 0.08v DC

F-6 - 4.92v DC

 

Since c-3 and D-4 are what makes it play and how the computer reads the cassette, i can assume that such low voltage, especially with the motor under c-3, is the cause of why the datasette is not working. I thought about tracking down a Sams guide for the Vic-20 to see if i can track down where thee source of the problem originates, but i have a hunch it's just age and bad luck. Thanks for y'alls input.

[carlsson]

Have you checked the fuse inside the computer? On the DIN style model, it only handles the 9V line.

 

 

 

F1 1 AMP FB FUSE, 9 VOLT AC SOURCE

Opening screen normal and all functions work except cassette motor and 9VAC source to user port.

http://personalpages.tds.net/~rcarlsen/cbm/vic20/vic20.txt

[bpatte02]

huh... thats interesting. i'll have to replace that and see if that works. thanks for the info!

[7800fan]

my vic-20 uses a 7 pin DIN and i replaced the original power supply with a after market one made by Ray Carlsen after reading up on the potential harm original power supplies can cause. As of right now I'm not sure what else i can do. I did a DC Volt check on the port and it reads as follows:

A-1 - GND

B-2 - 4.97v DC

C-3 - 0.15v DC

D-4 - 0.38v DC

E-5 - 0.08v DC

F-6 - 4.92v DC

 

Since c-3 and D-4 are what makes it play and how the computer reads the cassette, i can assume that such low voltage, especially with the motor under c-3, is the cause of why the datasette is not working. I thought about tracking down a Sams guide for the Vic-20 to see if i can track down where thee source of the problem originates, but i have a hunch it's just age and bad luck. Thanks for y'alls input.

 

Low voltage in DC is expected because AC can't be read as DC. Usually you get near zero DC on AC lines. Try setting your meter to AC and recheck that 2 lines.

[bpatte02]

Update: I found the issue and was able to correct it. The transistor Q4 which is a D880 was faulty and not producing the correct power level on one of it's 3 lines. I replaced it and the datasette is working nicely. Thanks for all your suggestions.