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G8000 with no sound

Try with one driver board in, then whilst the DBT is bright, turn the bias trimmer down to see if you have them wound the wrong way. The amp will not get hurt with the bulb lit up, as the bulb is dissipating the energy.

Also you didn't happen to replace the two Zener diodes on this board with regular diodes did you?
 
I will try that, but I thought full clockwise was the lowest start point.
Once turned on and DMM is set and hooked up to TP terminal +/- what should i see if it is the right direction?

I did not change out the zeners.

Should I look for something before this step as the receiver will not even power on, no display or anything.
 
Powered up on DB with both driver board out.
Display lit up, bulb went dim, protection light flashed red then just went out with no relay click.
 
back to trying one driver board at a time i guess . the protect board may well be another issue . although it might be the problem in theory .
you could plug in one driver board and check the idle bias . and dc offset .it should give a clue .
 
When using either driver board individually it reads 175 mv and the turning the pot does nothing change it.

Should I try to reinstall the original ones?

The bias reads .3
 
thesaint said:
When using either driver board individually it reads 175 mv and the turning the pot does nothing change it.

Should I try to reinstall the original ones?

The bias reads .3
Click to expand...
So this 175mV is DC offset? - and you are adjusting the DC offset trimmer to adjust/change it?

Bias reads ".3" - what does this mean? - is this 'Volts' or 'milli-Volts' or 'milli-Amps' ? - and how are you measuring this - at what points?

I think you are using multi-turn trimmers, are you sure you are turning them enough? (25 turns end-to-end) it wouldn't be the first time someone didn't turn them enough, and thought there was something wrong with them. :)
 
The +175.0 mv dc is the only reading on either ears/ bias test points with either driver board used. Turning the pots do not change readings.
Receiver will not light up or turn on. Bulb stays full bright.
 
thesaint said:
Bulb stays full bright.
Click to expand...
Well, you either have a short somewhere, some incorrectly installed transistors, a wiring error, OR the bias is turned fully up - and from your responses, seems un-adjustable.

This receiver is in a very fragile condition, don't whatever you do, be tempted to power it up without the DBT.
 
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thesaint said:
The +175.0 mv dc is the only reading on either ears/ bias test points with either driver board used. Turning the pots do not change readings.
Receiver will not light up or turn on. Bulb stays full bright.
Click to expand...
I think like John says, you have something installed incorrectly, diode the wrong way around, a PNP where there should be a NPN or something like that.......
You are going to have to go back over your work with a fine tooth comb.....

Can you take some fairly high resolution pictures of the driver boards so we can see the components clearly, one of us might be able to see something amiss.
 
I just figured it out, or some of it out.
The trans subs for the driver boards
2690A/1220A are ECB. The board reads EBC on all of them. Changing them out and bending the legs to EBC.
I don't know why I didn't think the subs were a different pin out. Sorry, I really feel like a dumb ass.
 
thesaint said:
I just figured it out, or some of it out.
The trans subs for the driver boards
2690A/1220A are ECB. The board reads EBC on all of them. Changing them out and bending the legs to EBC.
I don't know why I didn't think the subs were a different pin out. Sorry, I really feel like a dumb ass.
Click to expand...
You shouldn't have to bend any legs on the new transistors, there are extra holes pressed in the board to accommodate ECB, BCE, CBE, or EBC.....they all have them, see the screen printing....
 
Have them all in correct......
DB now goes dim as it should.
Full clockwise is 0 on bias, thank you kevzep. On the bulb, brought it up to +10 as I remember as I remember someone saying it will significantly increase once on main power.
Ok, still no relay click, and the protection red light flashes once turned on then disappears, no green light.
I did not have that originally, and remember I have replaced all relays with new.
I feel the elevator is going up instead of down.....
 
thesaint said:
Have them all in correct......
DB now goes dim as it should.
Full clockwise is 0 on bias, thank you kevzep. On the bulb, brought it up to +10 as I remember as I remember someone saying it will significantly increase once on main power.
Ok, still no relay click, and the protection red light flashes once turned on then disappears, no green light.
I did not have that originally, and remember I have replaced all relays with new.
I feel the elevator is going up instead of down.....
Click to expand...
What is supposed to happen, is when you turn the power on, the protector light flashes, whilst the protector light is flashing, the power light is not on.
Once the voltages have stabilised after a few seconds and the timing cap in the protection becomes fully charged after about 6-10 seconds, this will then activate the protection relay to pull in and then allow whatever speaker relays are selected to also pull in as long as there is no excess DC, or and Overcurrent situation happening.
Once this has happened, the Green POWER indicator will light up and you are good to go.

I suspect given your description, it is likely that a fault has occurred in the protection circuit.
BUT before that, you need to tell is how much DC is on the amplifier output BEFORE the speaker relays.
So measure that and let us know what that is. You should have also set the DC offset, you get quite a bit of adjustment on these amps, so much so you can trip the DC protection if its out of adjustment far enough.

If you have a Dim Bulb and its not bright any more, you can go to full mains, depending on what wattage bulb you are using, these amplifiers will not come out of protection with the limited supply through the bulb.
So as long as the bulb is dim, you are safe to move to full mains.
You might even find it will just fire on up.
 
kevzep said:
What is supposed to happen, is when you turn the power on, the protector light flashes, whilst the protector light is flashing, the power light is not on.
Once the voltages have stabilised after a few seconds and the timing cap in the protection becomes fully charged after about 6-10 seconds, this will then activate the protection relay to pull in and then allow whatever speaker relays are selected to also pull in as long as there is no excess DC, or and Overcurrent situation happening.
Once this has happened, the Green POWER indicator will light up and you are good to go.

I suspect given your description, it is likely that a fault has occurred in the protection circuit.
BUT before that, you need to tell is how much DC is on the amplifier output BEFORE the speaker relays.
So measure that and let us know what that is. You should have also set the DC offset, you get quite a bit of adjustment on these amps, so much so you can trip the DC protection if its out of adjustment far enough.

If you have a Dim Bulb and its not bright any more, you can go to full mains, depending on what wattage bulb you are using, these amplifiers will not come out of protection with the limited supply through the bulb.
So as long as the bulb is dim, you are safe to move to full mains.
You might even find it will just fire on up.
Click to expand...
he tried without driver boards .or so i thought i had read earlier .am waiting to see what has changed in the protect circuit since it apparently worked . sort of almost back to the beginning .
 
petehall347 said:
he tried without driver boards .or so i thought i had read earlier .am waiting to see what has changed in the protect circuit since it apparently worked . sort of almost back to the beginning .
Click to expand...
It will never come out of protection without the driver boards, so they need to be in.
I think he's resolved the issues with the drivers boards.
Just need to bias and set DC offset, should come out of protection if the protection is working properly.
It also needs to come off the dim bulb to come out of protection.

So we need a bit more info before we start diagnosing....
 
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