Marantz PM550DC idle current adjustment help

[Timp_aus]

Hello,
I hope someone could answer my question.

I have a Marantz PM550dc amp, reading the service manual on how to adjust the idle current it says to check the voltage at TP1 and at TP2 and I am not sure if I am checking correctly as the manual isn't very clear where to place the meter leads.

There are two TP1 test points and two for TP2.
I am not sure using my meter where I need to put my meter leads to check TP1, do I put both leads across both TP1 and the same for TP2, if I do this I and I adjust the pots R783 & R784 they are 0v without any change in voltage when turning the pots.

Thanks

 

[Pendraf]

I have the same doubt. Can someone help here.
Thnaks

 

[Pendraf]

I can answer to myself
I did a test and touch TP1 pboth points using tester (same for TP2) and it worked.
Now what I get is:
TP1 18mV
TP2 19.6mV

Reference manual says 12mV

I do not know if makes sense now to adjust them (using R737 and R738 (manual is reporting 783 and 784 but it is not correct).

I have also tested aoutput DC and I this is what I have
Right Channel 1.5mV
Left Channel 3.1mV

not 0 but should be ok.

Am I wrong?

 

[williamK]

Been tinkering with the 550dc for a year. replaced Q747 op amp- most resistors and parts around Q733 and Q717- All 4 main output transistors and the protection relay. This model US has no fuses. Upon power up it self destructed. After the second rebuild, it was fired up at low voltage (30 VAC in ) and brought up slowly. The amps started spiking at 40 vac input. At this point I adjusted the idle currents to around 0 and slowly increased input power. If you still have a problem, the amps will go up above .75 and you will have to back off and go looking. If you get up to 120vac in and it's still holding, adjust the idle currents now. R737 to set across both TP1 pins and R738 to set across the 2 TP2 pins.