hifi engine

Akai AM-U55

nobeal85's picture

hello
I have a problem with my AKAI AM-U55
before there is no sound, I change:
STK2155
STK3042
TA 7317P
as soon as I turn it on, then relay slap .. if I get a little volume, the relay down...
I will change the transistors but when I note the tension, they correspond to the diagram (45 volt and I -45volt instead of the 43 listed)
I also changed the capacitors (one was inflated)
thank you for you help
Ben



Re: Akai AM-U55

Are both the 10,000uf filter capacitors good? If not there may be an imbalance, especially when current is being drawn.

nobeal85's picture

Re: Akai AM-U55

hello
yes capacitors are all new, 10 000uf - 65V
I have only schematic (in hifiengine) and when I took the voltages they are all good.
i need a schematic diagram for to understand how and why as soon as I get a little volume that makes the relay clinched..
many thank
ben

karodimitrov's picture

Re: Akai AM-U55

When you changed STK is possible to have some deviation of the outcome. Therefore it is better to check for 0V DC of its output.Increase the gain and measure.There must be 0 volts DC.

karodimitrov's picture

Re: Akai AM-U55

Check for DC voltage at terminals 2 and 3 of TA7317 and if necessary-set it to zero with VR1 and VR1'(center off-set voltage)-page 69 of the service manual.

nobeal85's picture

Re: Akai AM-U55

thank Karodimitrov

I mows the lawn (I'm enjoying the sun) and I'll start
I would give the new
best regards