Quad 99 Tuner problem

[barrymagrec]

I have a Quad 99 FM Tuner which switches off the whole system when warm. Does anybody have any ideas or know the whereabouts of circuits or Quadbus pinout information?

Barry

[firechief]

OK so this is a modern system that has a control interface to other componets.
See here discription.

"The 99 FM Tuner and integrated 99 CD Player are both connected to the rest of the system via our ‘Quad Link’ bus system, which combines complete system control with balanced line audio transmission."

Is it possible to seperate and run the componets? Does the tuner act as the control center for the other componets? Do any parts have a timer on/off feature? How long does it take for this to happen? When did it start happening? Have you made any changes to the setup or configuration about the time this started?

[barrymagrec]

The system runs O.K. with the Tuner removed from the bus. It is not possible (easily) to run the Tuner seperately since it is both controlled and powered from the Quadbus. There are individual on / off buttons on the Tuner, CD player and preamp but they all turn the whole system on and off, it is not pssible to power units seperately while they are on the Quadbus. The problem occurs between 20 minutes and 5 hours after switch on depending on ambient temperature but I have been unable to recreate it with the top off the Tuner so that I can poke around looking for clues. In my experience heating and cooling this type of fault is often highly misleading and I am reluctant to return the unit to Quad since it is likely to result in a "no fault found" report and a bill for £££.
This is why I was hoping someone might have previous experience or knowledge of Quadbus systms.

Barry

[Zombie]

Some early 99FM have a problems with a chip that runs havoc. The 99FM has a built in PSU, you just need to open it and fit a power cable to it and short out the quadlink supply...

[barrymagrec]

Originally Posted by Zombie

Some early 99FM have a problems with a chip that runs havoc. The 99FM has a built in PSU, you just need to open it and fit a power cable to it and short out the quadlink supply...

Thanks for your reply.
As I remember - and it`s been a while now - the tuner has it`s own transformer but this runs off the 30 volts up the quadlink. In any case, this would not sort the problem of the tuner switching off the rest of the system
I can believe that it`s the chip at the bottom of the problem as it`s a PIC but it`s not temperature sensitve (apparently) so difficult to prove. I hoped to blow a replacement PIC by copying the original but the correct socket was not available for the programmer and a colleague pointed out that the security fuses would probably be blown anyway. I Sourced a second tuner which works fine but unfortunately it`s the black version with a blue display so it doesn`t match the rest of the system.

[Zombie]

Just take change the guts?

[barrymagrec]

Originally Posted by Zombie

Just take change the guts?

That was plan A. Doesn`t solve the blue display problem though (as opposed to green) and as the new display has extra signal strength LEDs I`m not sure I can swap the main board alone. As well as extra LED`s the newer tuner has a switch on delay so I`m pretty sure the PIC is different (before you ask). Thing is, I`m pretty busy and the black tuner works so the whole problem has been put on the back burner somewhat. If I could get information on the quadbus pinout it might encourage me to have another look.

[Zombie]

I've got the 99 FM component list (with prices :-)), maybe it hels you to order a new part?

[barrymagrec]

Originally Posted by Zombie

I've got the 99 FM component list (with prices :-)), maybe it hels you to order a new part?

Thank you for the offer, I`ll bear it in mind when I get time to have another look at the problem.

[JRKO]

Where are you in the world barrymagrec?

If youa re in the UK you can send it to Quad themselves. They are really great. I had the 99cdp control preamp/cd player and they converted it to the lazy servo in a 4 day turnaround

If you are not tin the UK still try and give them a call - really great customer service