petehall347
the brandy coffee man
keep troubleshooting as you were .. sorry i just made an observation . i cannot recommend a simple replace something .
all i can say is if q804 is turned on it will shunt the base voltage of q805 to ground .
Nikko Alpha II speaker and meter audio output relay not clicking
- Thread starter EvanF
- Start date
all i can say is if q804 is turned on it will shunt the base voltage of q805 to ground .
thats true.. And .7 volts on the base of Q804 would bias the transistor on.. Pull and check Q801. Then --- C840 ( .47µf/50vdc) hasn't been replaced yet. Correct ?
petehall347
the brandy coffee man
i would try a different way and measure voltage at board pin 6 .ac voltage here . then d841 . cathode ac volts same as pin 6 then anode - voltage then follow circuit through if good ..
or just pull out q804 and learn nothing and see if relay clicks in .
q801 should clinch the deal .
or just pull out q804 and learn nothing and see if relay clicks in .
q801 should clinch the deal .
EvanF
AK Member
No, not the. 47 uF
EvanF
AK Member
Q801 has an HFE of 137, measure good. pin 6 had 43.8 VAC, cathode had same vac, abode had 19.77 VAC.
EvanF
AK Member
Relay clicked when I removed q804! Pete, many thanks. now, when I sell this amp, is it good to go? theres still a tranny missing....
petehall347
the brandy coffee man
i dont trust your meter .. or d841 is wonky .
petehall347
the brandy coffee man
no you cant do that .. its not good practice .. it just proves some things are working and others not .. it is the protect circuit and needs to be correct .
EvanF
AK Member
Alright, if that's the thing to replace, I'm good to go. So I can put q804 back in when I get a new diode? I might have to put some MOVS on the output in the meantime....
Just gonna chime in and say with how weird it's acting, and since it's just this circuit, you probably should replace all transistors and elec caps etc there to circumvent any future issues. Don't forget to clean the relay if you haven't already, I think the cover just pops off on that model, at least it did on mine.
Why waste time cleaning when a replacement is readily available.
EvanF
AK Member
V
Cleaned the relay with d100, replaced three caps. Monday I'll stop by Gateway Electronics to pick up a diode and the caps. I can substitute for the same forward voltage and max voltage, and I should be good... I did that for a diode on the "regurator" board to get the light working. Worked great.
Cleaned the relay with d100, replaced three caps. Monday I'll stop by Gateway Electronics to pick up a diode and the caps. I can substitute for the same forward voltage and max voltage, and I should be good... I did that for a diode on the "regurator" board to get the light working. Worked great.
petehall347
the brandy coffee man
the diode needs testing or simply replacing then it may or may not fix the issue .
please do this correctly or some unsuspecting person might get fried speakers
please do this correctly or some unsuspecting person might get fried speakers
I mean yes but hey, if it's not too hard to clean and not being flakey, sometimes I like to be cheap.
EvanF
AK Member
The hum in this thing is pretty bad compared to my other 200 watt 120 dB s/n amp (waiting in the shop....) so I'm eager to sell.
EvanF
AK Member
A mov would work on the outputs right?
petehall347
the brandy coffee man
lost me with mov ..
while you have relay clicking in double check dc voltage at speaker terminals ...
we just lost an hour here so must go now ... it is suddenly 2.30am . i didnt even think it was 1.30am yet .
while you have relay clicking in double check dc voltage at speaker terminals ...
we just lost an hour here so must go now ... it is suddenly 2.30am . i didnt even think it was 1.30am yet .
EvanF
AK Member
Metal oxide varistor to stop current when a voltage is reached. anyways, 0 VDC on the speaker outputs. I put in a random diode, high voltage with same forward voltage as d841.
EvanF
AK Member
Let's talk some more tomorrow afternoon.
