problem with my 999

what happens with left and right cards pulled out ?
please check where the cards plug in to see nothing can move and cause a short circuit .
it does seem there is an intermittent problem .
 
you said one card was blowing fuses and then was ok ..and with other card in first card is playing up again yes ?
sorry just trying to figure out what might be happening here .
 
sorry, my English is not to good
I have one 1159 card completely redone, transistor, caps and resistance, that the one that I use the most but normally I used both to see if its a 1159 problem or not
at the beginning when I was putting the 1159 on the right channel it was blowing the positive fused on that side
now I can stay connect the 1159 on that side but, when I do that it blow fused on the left channel
 
just to be sure the speaker outputs arent shorted try measuring ohms from speaker fuses to ground .with the power off .
 
Yeah I am struggling with this one, I suspect its the language barrier.

So, ONE 1159 board is good right?

Try this good 1159 in BOTH channels, then see if the fuse blows.
 
stevestadler said:
and I'm sorry about the language
Click to expand...

Don't worry about that, sorry we don't speak French, I should have taken more attention in French language class at school!!

OK, so the good board can blow a fuse in one channel. OK, this is easy, there is not much that can be wrong.

There is either a failed driver or output transistor, or the driver transistors are mounted the wrong way around, or there could be a mica insulator missing.....
You need to test all these transistors.
 
with having limited knowledge on this unit i have been trying to figure out if the outputs receive power with no driver board installed ?
as far as i can see they do but i need to know if this is the case or not ?
 
check the board that is blowing the fuse for ohms from connector 14 to all other connectors to look for an obvious short circuit .
i am scratching my head why or even how it is possible for the right channel to blow the left channel fuse . unless it has been wired wrongly by someone . and swapped over the b1 and b2 .
 
Could be the drivers are reversed to what positions they should be in....That would cause some issues like fuses blowing etc etc
 
here were I am now, the first 1159, the one I was using since the beginning still blow fuse on the left side, when install on the right side
so I build the other 1159,this one doesn't blow fuse but r825 overheat
I change all transistor again, change all resistor, all the cap, change the diode
I just don't know
 
Stevestadler, you are in excellent hands with Kevin and Pete helping along. On those diagnostic cases you don't want too many cooks in the kitchen. I do have one suggestion which is to really be systematic and work in compartments and steps. For instance. Get the driver /output situation sorted out. Be 100% sure those are working and in right positions. ( I believe the 1277 / 1231 are sorted out)

Then put a little sticker on each driver board, referring to them only as board A and B instead of left right.

Once the amp is stable without driver boards, begin with left side of amp only and test with driver board A / B respectively and note down exactly what happens. Repeat for right side.

As we do this in strict compartments it may be easier to work deduction. This may also establish a good vs bad driver board or good vs bad amp side, giving you a reference to measure/ compare against.

On my own 999, I ultimately ended up with a good vs bad driver board. All components were correctly installed and tested OK individually on each board. This logically left the traces/solder joints as last possibility. By knowing with certainty which board was working I now had a reference to compare trace continuity. It took only 10 min. to identify a hairline crack in a trace and a bad bad solder joint, impossible to see with the eye.

You will get this !
 
Hi guy, just been release from jail today, about a years , not really im just joking, i been really sick and they couldn't find the problem, but i'm back now hopefully for a while

i start working on my 999 again

. im working on the voltage right now, im about 10 v over all around. -32 instead of -22

i notice that the voltage on the f-1230 is off, both blue wire connecting to OD and OE are at 30 v Ac, the problem is that the other end,my OH is -24v (closed to spec) and my OG is at 34, 7v over the spec, i got 10V from gray wire, i don't know what that voltage is suppose to be

i went on my F1228 board to test the transistor tr601 and tr602 both emitter are at -5.5v, the schematic show -3.8 both my connector are at -32 instead of -22

i went to my 1159 to try adjusting the current, the max i could get was 20mA short, about 10 mA under the spec

could it be a bad power supply? Please help

P.S. i have 2 set of boards and both give me the same voltage so it doesn't look like a boards problem
 
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