Anyone have a high resolution picture of the power supply driver area?
Some attempted a repair in this and never fixed any of the blown traces
Some attempted a repair in this and never fixed any of the blown traces
Ok I put new drivers in this amp and repaired some traces .
The amp will draw excessive current .
Here is what I get for the drive signals on the power supply fets .
Scope set to 10us 5volts/div
These pics are with the fets installed and a current limiter inline with the B+
The amp will draw excessive current .
Here is what I get for the drive signals on the power supply fets .
Scope set to 10us 5volts/div
These pics are with the fets installed and a current limiter inline with the B+
Attachments
If this is at 10us, the frequency appears to be too high. At 10us, you generally have about 3 complete cycles. Here, you have nearly 8.
Here is what I get now after some adjustments to the scope .
Do these look ok ?
Scope set to 10us 5 volts div
If so I think I have a shorted transformer .
The amp will draw current for a second when only power and ground are connected .
Then if I hook remote voltage to it it will draw excessive current if I flip the amp over so solder side is facing up the amp idles perfectly fine . But if I face component side up the amp draws excessive current
Do these look ok ?
Scope set to 10us 5 volts div
If so I think I have a shorted transformer .
The amp will draw current for a second when only power and ground are connected .
Then if I hook remote voltage to it it will draw excessive current if I flip the amp over so solder side is facing up the amp idles perfectly fine . But if I face component side up the amp draws excessive current
Attachments
Did you try twisting the transformer to see if it made a difference?
Was the trace aligned with the reference before checking the signal?
Is there something on the bench that's conductive?
Was the trace aligned with the reference before checking the signal?
Is there something on the bench that's conductive?
If you twist the transformer makes no difference .
If you let the amp sit for awhile when powering up it will be fine for about 2 mins then out of the blue it will start drawing excessive current. If you flip the amp over it will be fine for 30 secs then start drawing current again .
It’s weird when you hook ground to it then hook b+ up it will draw 60 amps of current for a split second then be fine .
And it’s hit or miss when trying to power the amp up sometimes it’s fine other times it draws current right off the bat .
The reference line was centered when checking for drive signals . From what I can see in the pics it’s not pulling fully back to ground
If you let the amp sit for awhile when powering up it will be fine for about 2 mins then out of the blue it will start drawing excessive current. If you flip the amp over it will be fine for 30 secs then start drawing current again .
It’s weird when you hook ground to it then hook b+ up it will draw 60 amps of current for a split second then be fine .
And it’s hit or miss when trying to power the amp up sometimes it’s fine other times it draws current right off the bat .
The reference line was centered when checking for drive signals . From what I can see in the pics it’s not pulling fully back to ground