CPC 464 tape issue

[HairyBeast]

Hello I have a amstrad cpc464 64k I'm working on I've solved everything do far. It powers on ok everything working except tape drive. I do run or load it says press play and any key. I press play. The button goes down then I press any key it stops the tape and won't stay down if I press it. Any help would be appreciated 

Thank you

[Bryce]

Have you tried other tapes or without a tape at all? It sounds like the tape you're using is seized up.

Bryce.

[HairyBeast]

Tape is fine it's instant the second I press any key it stops I've checked the switch for the play mechanism being engaged is working and it is.

[HairyBeast]

I've tried with other tapes same thing.

[HairyBeast]

I'd also swapped the belt for a new one ffwd and rewind work fantastically 

[arnoldemu]

the play button will not stay down?

do you hear the click of the tape relay activating?

is the tape motor active with play button down before you press a key?

from basic you can activate the tape relay and tape motor which might help diagnose this?

OUT &F600,&10

tape motor should be on

OUT &F600,&00

tape motor should be off.

[HairyBeast]

Play button will not stay down. I hear no relay

The command don't turn the motor on

[HairyBeast]

I'd really like the tape working with bluetooth also. I had problems on the 128k spectrum with enabling both. But first things first tape drive working 

Play stays down turned off

[HairyBeast]

The OUT &F600,&10 Command stops the tape instantly play is released I heat the deck stop but I'm not sure about a relay

[arnoldemu]

See the cpcwiki for the service manual. It does seem like the cassette player part of computer thinks it has come to the end of the tape Service Manuals - CPCWiki

[HairyBeast]

What for specifically someone must have encountered this issue before in 40 years. I am going to recap anyway. It doesn't even try to tune so why would it think it's reached the end.

[Bryce]

What for specifically someone must have encountered this issue before in 40 years. I am going to recap anyway. It doesn't even try to tune so why would it think it's reached the end.

The auto-stop is purely mechanical. Recapping won't change anything. There is a white plastic "blade" sticking out between the two heads. Pressure on this is what disengages the motor and pops the play button back up. If this is stuck or rusted it will cause the issue you're seeing.

Bryce.

[HairyBeast]

But it's activated my the computer I can press play then when the anykey is presses after run" it stops play goes up no motor no try nothing else

[HairyBeast]

Well motor working after recap. Now I'd like to know where I can connect the Bluetooth cheap audio board to have both working . I connected it to between both amps and I think k it's a bad idea the tape won't load neither will the Bluetooth. I'd ideally like both at the same time.

[HairyBeast]

Tape loads perfectly with bluetooth removed. But I really would like both to work together. I got both to work on my spectrum 128k.

[Bryce]

What's the device you're trying to connect and what output impedance does it have?

Bryce.

[HairyBeast]

I'm not sure the impedance but it's one of the generic Chinese ones

https://a.aliexpress.com/_EvFPNZY

[Bryce]

The best point to feed in this signal is probably pin 9 of the LA6324, but I would add a small ceramic capacitor in series (about 47nf) and a trimmer pot between the module and the capacitor to tune the signal level.

Bryce.

[HairyBeast]

What value pot do you think

[Bryce]

Without knowing the details of the BT device I can't calculate it. I'd try something around 100k LIN and see how it goes.

Bryce.

[HairyBeast]

I'll have to order I only have 10k and 20k.  Some 4.7nf and maybe some 22nf somewhere

[Bryce]

Try the 20K and 22nf. The pot should be used in a potential divider configuration.

Bryce.

[HairyBeast]

The problem is the tape drive not working with that connected maybe a diode so the Bluetooth audio is only one way

[Bryce]

The problem is the tape drive not working with that connected maybe a diode so the Bluetooth audio is only one way

That's what the capacitor does. The output impedance of the BT module is effecting the signal from the real tapedeck. The capacitor DC isolates the BT signal from the CPC amplifier. Although a diode might work in this particular situation, adding a diode to a sound signal usually won't work as most sound signals are oscillating above and below the ground, so it needs to be able to flow in both directions.

Bryce.

[HairyBeast]

I've got some ordered I'll wait. Thank you for all your help. Will I need to be able to adjust the linear pot when I want to use it or is it a one off adjustment. I'm just trying to plan where I would put it.