Need help ! Pioneer GM-2200

[stuparumihairadu]

Fixed the previous one.Now I got this one.

Problem : I made the rem_bridge, it receieves 12v, the LED lights up, i can hear the rellay clicking on/off (ofc when i power it up, and when I turn it off).

Problem no sound in speakers.

The following : i have checked the tranzistors as in the previous pioneer model (gm-2000a ) and they all are in good order.Nothing is "fryed".

The thing is that I have 2 switchies in the amp somebody can tell me about them?
theyre highlited with black , and the reds are the final tranzistors.

Plese help.

Thx a lot !

p.s. 1

thers a single volume know in the form of a hole in the amp case, wich leds to a screw, turning it from 400mv to 4V, rca level input. if it helps

p.s. 2

i`ll attach documentary needed

[Perry Babin]

The attached document is for a CB radio.

[stuparumihairadu]

sorry...

this is the link for the schematics.

http://www.eserviceinfo.com/download...%20GM2200.html

[Perry Babin]

Email it to me.

babin_perry@yahoo.com

[Perry Babin]

The components circled in black are the bias potentiometers. They are used to set the idle current for the output transistors.

[stuparumihairadu]

Originally Posted by Perry Babin

The components circled in black are the bias potentiometers. They are used to set the idle current for the output transistors.

I see.I remember now. I read soemthing about the idle current for the other amp.Gm-2000a.

Question.In wich direction do I need to turn them?I can`t find anything on the itnernet about them.
If I go back and read about them on the gm-2000a amplifier, should I find similarities?

Thanks.

[Perry Babin]

Generally, turning the bias post clockwise will increase the idle current. Turn them slowly to prevent excessive current flow through the output transistors. Have all transistors tightly clamped to the heatsink before attempting to adjust the bias.

[stuparumihairadu]

Originally Posted by Perry Babin

Generally, turning the bias post clockwise will increase the idle current. Turn them slowly to prevent excessive current flow through the output transistors. Have all transistors tightly clamped to the heatsink before attempting to adjust the bias.

the gm-2000a amplifier has them turned at half. both knobs.

for my information, whats the difference if I have them opned all the way , half, of if I turn them counterclockwise all the way??

in the manual of the gm-2000a it says for adjusment of the idle turn counter clockwise.turn power on and wait for 30 min.

whats that suppossed to mean?

[Perry Babin]

If you turn them fully clockwise, the output transistors will likely overheat and fail.

You adjust them and let the amp idle (no speakers connected, no input signal) and re-check it. You have to do this to make sure that the bias doesn't drift and remains very near where it was set.

[stuparumihairadu]

Originally Posted by Perry Babin

If you turn them fully clockwise, the output transistors will likely overheat and fail.

You adjust them and let the amp idle (no speakers connected, no input signal) and re-check it. You have to do this to make sure that the bias doesn't drift and remains very near where it was set.

Thats a bit of a problem.I don`t remember wher it was set.foolish of me, I tempered with them.