Lasonic TRC-931 Doesn't light up

[guizmop]

Hi guys,

I recently purchased a Lasonic TRC-931.
Not a single LED lights on, radio doesn't work, tape doesn't work, external source (CD) doesn't work... Nothing works!
I tried with batteries and power cord but same result.

I opened it to inspect the inside and nothing seems to be broken. All electronic components look good, nothing burnt, no wire disconnected etc.
The wires coming from the battery rack do give 15v.

I was looking for a kind of diagram or schematic to help me trouble shooting. If someone knows where to find that, it would be great.
If any one also has an idea on what to check or a common source of problem that could also help.

Just FYI, the LEDs do work, so do the speakers, and the tape reader electrical motor, I checked them independently.

Thanks a lot,
Cheers,
William

 

[BassHead]

Hope you solve it. I'm not good at electronics...but could the fuse be blown...generally located near the transformer. Also maybe issues with the transformer? It sounds like something further upstream since radio / tape / everything doesn't work.

Do the LEDs work or not? How can you tell the speakers work?

 

[guizmop]

The issue seems to be somewhere after the transformer, I know for a fact that I get 16V at the output.
No led light up but I tested them with a seperate power source and they work, same for the tape motor. I tested the speakers by connecting them directly to another separate source (mp3 reader), directly connected to the soldered connections (not using jack or other "CD" source).

 

[docs]

AnalogAlley is the only place to have the lasonic 931 manual on the planet. Sounds like you will need it.

 

[guizmop]

Thanks, that really helps indeed. Do you know what components are the most likely to fail? My understanding is that the resistors are pretty robust but the condensers are more fragile. Any idea?

Cheers,
W.

 

[docs]

I would trace through where the power is provided (testing probably to be done using DC but the manual should say) and make sure fuses are good as mentioned then check the voltages at each stage through each component. My guess would be a capacitor or resistor but often when there has been no power getting through it has been transformer related.

 

[JVC Floyd]

Look for any bulging caps on the boards , one bad cap is enough to make things go kablooey.