Repair a Geneva Lab Model L

[andreeb]

Geneva Model L - Sound system
Age: Appox 10-12 years.

Im not sure what is wrong with the unit. A small fuse broke thats on one of the PCBs, I replaced it but made no difference. Ive taken out every PCB board and cleaned them with qtips/electric spray, but made no difference either.

The small green LED powers on when I hit the power button / functions like FM/DVD etc, but quickly fades out in 1-2 seconds.

Im wondering if you can help me finding out what may be wrong / if there is a visible faulty transistor/etc.

Any help would be greatly appreciated.

Thanks for taking a look.

 

[andreeb]

Some more pictures of the PCBs

 

[Harald Kapp]

A small fuse broke thats on one of the PCBs, I replaced it but made no difference.

Usually fuses trigger for a reason. Inspect the circuit downstream ("output" side) of the fuse for visibly defect components. I suspect one of the components got a short circuit and triggered the fuse. Since with a new fuse no short seems to exist, this component likely went open circuit after the short circuit.
On your images, where is the fuse? please mark it so we know where to look.

 

[andreeb]

Usually fuses trigger for a reason. Inspect the circuit downstream ("output" side) of the fuse for visibly defect components. I suspect one of the components got a short circuit and triggered the fuse. Since with a new fuse no short seems to exist, this component likely went open circuit after the short circuit.
On your images, where is the fuse? please mark it so we know where to look.

Ive marked it off on a new picture, i also think ive found the problem. Seems it might be a capacitator that is causing the problem, ive marked it with an arrow.

 

[Harald Kapp]

This one looks really bad. Replace it. Also check the other electrolytic capacitors. Where one fails the next is not far away.

 

[bertus]

Hello,

That capacitor really looks bad.
Here is a page how to visualy spot bad caps:
https://www.robotroom.com/Faulty-Capacitors-1.html

Bertus

 

[andreeb]

I temporarly took out the card, and plugged in a 5v 2amp driver, and its working perfectly. Not sure of the power rating of this card, the big blue condensator says 5v 1A, so im guessing this is the rating. Getting the condensators replaced tomorrow, hopefully this will fix it. If not ill replace it with a regular transformer/driver and use that instead.

 

[andreeb]

Just replaced the condensators, working like a charm!

Thanks for the help provided

 

[Juldomange]

I have a Geneva sound L old model with 30 pins and NO Bluetooth, the 30 pins dock is broken, is it possible to get it changed to a new version ? To be able to plug a Bluetooth converter ?

 

[vikkheterpal]

Good Morning -- I also have a GENEVA XL and the problem is a bit different - the midrange and subwoofer seem to go in and out intermittently.. something seems loose because if you whack it on the side it will come on.

Now it is just powering the tweeters. Any advice?

Thank you in advance for your time and counsel.

 

[Goodsam77]

I have the entire service manual, apparently it's too large to upload here, 5.15mb compressed. Let me know how to send it to you and I'll send it to you I just don't know how to do it post it on here

 

[Voodooman]

I have a Geneva XL, first model without Bluetooth. There is no sound, but all voltages (5V st.by, 48V, 5V and 12V from main PCB) is ok.
CD is spinning, display is also good. I have checked capacitors, and found no problem with them. The amplifier board is disassembled, and no signs og burned or shorted output MOSFET's. If I had a diagram, I could check if it is any protect circuit that is active. Does anyone have the service manual? Goodsam77, you write that you have it, maybe only for the L model? It may still be a similar protect circuit, so I would like to have it.

 

[Crocker]

@Voodooman
If you still struggling with the faulty Geneva XL, maybe I can help: You should check the 1.8V voltage regulator IC 401 on the Amplifier PCB:

This is a most common failure on the XL amplifier. In case of damage it just outputs about 1.3 Volt instead of 1.8 Volt

 

[Voodooman]

Crocker,
Thank you for help with this problem. Yes, I am still struggling with it, hoping for a schematic for the model. Your picture is not the same as my PCB, I have a rev. 3.1 board. But I checked the regulators on my board. It seems like the 1,8V and 3,3V regulators was fine, but the 3,3V was low due to high current draw. I used an external 3.3V supply, and with 0,9A current, one prosessor got a little hot. And now I measured all the output transistors again, and some of them was now short circuited, along with broken R047 resistors. So if the big prosessor is fried, I think maybe I will need a new amp. board, if possible. I have not found any.

 

[Crocker]

I had a 2nd XL amplifier board on my work bench which had burned MOSFETs and 0,047 Ohm resistors on all 6 output channels. In addition some small transistors and 100 Ohm resistors on the other side of the PCB were broken as well. The following picture shows the componets in question:

Beside to the Power MOSFETS all these components are part of the current sense circuitry.
You should check all these resistors and transistors (4 per channel) and replace them if they are broken! If you just replace the MOSFETs and current sense resistors (0,047 R) they might blow-up again as long as the current sensing and thus limitation doesn't work properly.
Finally I got my amplified back to live but it took a lot of (micro) soldering work. Unfortunately the 7414/7415 MOSFETs are currently not available (i still got some on eBay in February) but I think you can find compatible types (>= 60V Uds, <100mOhm Rds and ~5-6 Ads).
I wish you success!