What I am seeing is the U400 side dip a little. When the voltage dips d400 shuts off completely. Waits half a second then turn back on. U400 never shuts off voltage just dips slightly. I am assumming D401 is the same style diode. This diode does not behave that way.Perry Babin said:
Thanks for the part numbers and measurements.
The voltage on pin 1 of U400 should swing from ~1v (when Q400 is on) to nearly 12v (when Q400 is off).
Q401 is used to switch power to a different circuit so it won't react the same way as Q400. I think this controls the power supply to the low voltage transformer drive circuit.
With the scope probe grounded directly to the ground terminal of the amp and the probe on the B+ terminal of the amp, 'precisely' how low is the voltage dropping across the B+ and ground terminals as the amp tries to power up?
Q401 is used to switch power to a different circuit so it won't react the same way as Q400. I think this controls the power supply to the low voltage transformer drive circuit.
With the scope probe grounded directly to the ground terminal of the amp and the probe on the B+ terminal of the amp, 'precisely' how low is the voltage dropping across the B+ and ground terminals as the amp tries to power up?
There you guys are...I was snooping and found this thread. It will be interesting to see what happens. Though if you get stuck, send it my way. 😉
Aaron
Aaron
Perry,
It'll be a couple days before I can get the power supply drive transistors off. I don't have a good enough solder iron station at home for that. Since these are toast and prevent the pwm from driving the transistors. I want to make sure I am just not overpowering the drive circuit of the pwm before I debug the pwm supply circuit any further.
Your a valuable resource on this forum thanks again!
It'll be a couple days before I can get the power supply drive transistors off. I don't have a good enough solder iron station at home for that. Since these are toast and prevent the pwm from driving the transistors. I want to make sure I am just not overpowering the drive circuit of the pwm before I debug the pwm supply circuit any further.
Your a valuable resource on this forum thanks again!
I am working on the same amp, and I forgot to mark the order of the transistors (only the heat sink mounted ones) so if some can post the order that would really help me out. I de-soldered them, and now I am pretty stuck...
Thanks in advance,
Alan
Thanks in advance,
Alan
Looking at the face of the transistors...
The 4 on the left are IRF540s.
In the group on the right, the left-most one is the rectifier, the rest are IRFZ44s.
The 4 on the left are IRF540s.
In the group on the right, the left-most one is the rectifier, the rest are IRFZ44s.
I have the 4 540's then I have the sensor, then the diode.
so the next 8 spots are for Z44n's? i have an extra 540 then, or I messed up bad...
so the next 8 spots are for Z44n's? i have an extra 540 then, or I messed up bad...
First off, thanks for your help so far!
Does anyone know where to locate the data sheet for the diode? I've checked ICMaster.com and of course google. I cant seem to find what kinds of specs it needs to find a replacement.
T432
SFI606G
-|>|.|<|- <--- thats the symbol on it, two diodes pointing at
eachother.
^^^ Thats what I see, for sure one side of the diode is bad
If anyone know the specs, or an known working replacement, then I should have this amp up and running today.
Thanks in advance,
Alan
Does anyone know where to locate the data sheet for the diode? I've checked ICMaster.com and of course google. I cant seem to find what kinds of specs it needs to find a replacement.
T432
SFI606G
-|>|.|<|- <--- thats the symbol on it, two diodes pointing at
eachother.
^^^ Thats what I see, for sure one side of the diode is bad
If anyone know the specs, or an known working replacement, then I should have this amp up and running today.
Thanks in advance,
Alan
Would an NTE Replacement work? I should be able to get it locally without ordering over the net
Here is the datasheet of the NTE:
http://www.nteinc.com/specs/6200to6299/pdf/nte6240_44.pdf
Here is the datasheet of the NTE:
http://www.nteinc.com/specs/6200to6299/pdf/nte6240_44.pdf
NTE rectifiers 'may' work properly. With NTE transistors, you never know exactly what you're getting. I'd recommend that you never use them.
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