Help me identify the damage. Tivoli Model 1

[bestever]

First of all, this is my first post ib this community, although I've been reading for a while.
I dont know where this thread suits best, but found some other Tivoli threads here , so I thought it would be ok.

My Tivoli fell from my desk.
It's not completely dead, but instead i can tune in some stations and hear some heavily destorted "music".
Another weird symptom is that volume knob doesnt respond in radio (it does when aux in is connected) and even when volume is set to zero the sound level remains the same
It was unplugged from power if that matters.

Here's a youtube link of a video I made to show you what I mean.
Damaged Tivoli Model 1 - YouTube

Any ideas what might have been damaged?
Thanks in advance.

George M.

 

[Mooly]

The damage has to be physical such as cracked PCB print.

If anything heavy is on the PCB (transformer ?) then areas around that are suspect due to the transformer weight and its mechanical inertia when the thing hit the floor. Also damage around anything that stick out such as any controls etc.

Components themselves won't be damaged by high G forces, it's the mass of them and the consequential damage that is the problem.

So you are going to have to strip it down and look carefully.

 

[bestever]

Thanks for fast reply.
I allready have the radio striped and inspected pcb and coconnectors.
Unfortunately, none of the above seems to be broken or unpluged.
Not 100% sure though, but did examine it carefuly.

If "phusical" damage is not the case, then what could be damaged?
Amplifier transistor?
Radio receiver transitor?
Volume pot?
Tuner? (dont know what's behind that knob)
Transformer? (it works, because the damage remains when on external power supply)
Driver?
Something else?

here are some pictures of what's inside

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[hm4nine]

Being familiar with Tivoli service it seems to me that the tuner board has a problem. You cannot service it for yourself, Tivoli´s service policy is to change the defective module. Changing the tuner module is rather easy and can be done within 15 minutes. Ask your dealer; may be you have luck and he can organize a substitution module for you from the importer.

 

[bestever]

A year ago, or more , when the accident happened, I called Tivoli's service.

I was told that it is the tuner board ( I am very suspicius on that, as far as I wasn't talking to a technician and no further questions where asked ; I only told them that it doesnt work after it fell)
And that the service cost would be ... (i dont remember the exact price, but it was something around 100 euros)

Well here I am a year after, trying to fix it my own, because I dont want to pay half the price of a new one and because I'm affraid that even if it's not that the damage, I will still be charged by that amount.

So, If tuner board is damaged, sound from aux in souldnt be ok?
Instead , when connecting aux in, sound is still terribly distorted.

Thank you for your replies.
George M.

 

[currentflow]

You could check for hairline breaks in the PCBs tracks with a continuity tester. Also check the cables' continuity between the various boards. Board cracks may not be visible with the naked eye. Unless the AUX audio is processed on the tuner board itself, it is fairly unlikely to be responsible. Check the volume control for open earth connection too.

Regards,
currentflow

 

[bestever]

Thanks for your input currentflow.
Checking pcb continuity seems to be a lot of work , but I'll do it.
I find it difficut to see how cables could be damaged so I'll probably skip this step.
Finally, could you please tell me how to: " Check the volume control for open earth connection" ?

Thanks in advance,
George M.

 

[currentflow]

Thanks for your input currentflow.
Checking pcb continuity seems to be a lot of work , but I'll do it.
I find it difficut to see how cables could be damaged so I'll probably skip this step.
Finally, could you please tell me how to: " Check the volume control for open earth connection" ?

Thanks in advance,
George M.

It's not so much damaged cables, but more their terminations which may have suffered. Regarding the volume control, check that you have actual continuity along the visible routes the control's three connections follow.

Regards,
currentflow

 

[Mooly]

Thanks for fast reply.
I allready have the radio striped and inspected pcb and coconnectors.
Unfortunately, none of the above seems to be broken or unpluged.
Not 100% sure though, but did examine it carefuly.

If "phusical" damage is not the case, then what could be damaged?
Amplifier transistor?
Radio receiver transitor?
Volume pot?
Tuner? (dont know what's behind that knob)
Transformer? (it works, because the damage remains when on external power supply)
Driver?
Something else?

Thanks for the pics,

All the electronic components would withstand a drop on the floor (and many many times more than that).

Damage is most likely in places such as where the knobs stick out by either direct damage to the part (volume control etc) or by cracking the print or joints on that part.

Does the volume control actually turn down the level of distorted sound or not ? Thats a big clue.
Volume controls normally have three pins. One and pin goes to ground (check it) and the other end pin goes to the audio feed. The centre pin is the "wiper" and moves along the resistive track that runs between the end pins. It's possible the track could be cracked if the pot took an impact on the knob.

If the tuner were faulty on its own then I would expect auxilliary input to be OK.

 

[russmacman]

Parts for my Model one

My stations for my Tivoli model one is so far off the actual dial. It's having problems tuning into a station and if you just touch the dial the station is gone. Is there a way to adjust or is there a replacement tuner that i can install? This version has the aux setting. Thanks in advance.

 

[tiefbassuebertr]

Thanks for fast reply.
I allready have the radio striped and inspected pcb and coconnectors.
Unfortunately, none of the above seems to be broken or unpluged.
Not 100% sure though, but did examine it carefuly.

If "phusical" damage is not the case, then what could be damaged?
Amplifier transistor?
Radio receiver transitor?
Volume pot?
Tuner? (dont know what's behind that knob)
Transformer? (it works, because the damage remains when on external power supply)
Driver?
Something else?

here are some pictures of what's inside

Good pictures. Thank you for this.
Check out also this thread:
http://www.diyaudio.com/forums/solid-state/181335-tivoli-model-one-vs-klh-model-twenty-one.html

 

[TANDBERGEREN]

Isn't the radio entirely built up around a TDA7000 cirquit?

Theese are not the most stable ICs on market.

 

[freax]

I would go over this entire PCB with a soldering iron, I can see a possible dry joint right from where I'm sitting.

Its possible that the drop has caused a crack in the solder, this PCB does look like the type that you would expect to have a crack form in, its not exactly a fiberglass type you know...

But just to be better safe than sorry, unplug it, get a 30 watt soldering iron and a spool of solder, then go over every single soldered joint here and heat it up and add a tiny little bit of solder (not much at all) and make sure that you don't bridge a connection in the process.

You shouldn't have to apply heat to the contact for any longer than 3 seconds tops with a 30watt iron, then move onto the next one, then repeat.

Then come back here and tell us if it worked or not.

 

[tiefbassuebertr]

I would go over this entire PCB with a soldering iron, I can see a possible dry joint right from where I'm sitting.

Its possible that the drop has caused a crack in the solder, this PCB does look like the type that you would expect to have a crack form in, its not exactly a fiberglass type you know...

But just to be better safe than sorry, unplug it, get a 30 watt soldering iron and a spool of solder, then go over every single soldered joint here and heat it up and add a tiny little bit of solder (not much at all) and make sure that you don't bridge a connection in the process.

You shouldn't have to apply heat to the contact for any longer than 3 seconds tops with a 30watt iron, then move onto the next one, then repeat.

Then come back here and tell us if it worked or not.

I agree. Particularly temporary errors and dropouts, that I had observe in several cases, disappeared completely after performing this carefully - please note: "Made in China", not "Made in USA" like KLH model "TWENTY ONE" like here:
KLH Model Twenty-One (21) FM Radio (1965)

Isn't the radio entirely built up around a TDA7000 integrated circuit?

Not in the versions, that I know.
I know only versions with TEA5710 - for datasheet go to post #1 about
http://www.diyaudio.com/forums/solid-state/181335-tivoli-model-one-vs-klh-model-twenty-one.html