Kustom Profile System Two schematic?

[Sowhat]

Been getting in more and more PA gear and many with whacky problems, this one's no exception. I have a Kustom Profile System Two with the complaint that it cuts out, and indeed it does. Works for a little bit then cuts out for a little bit then works again and so on. I figure it's probably a bad solder on something that gets hot, anyway, it seems to act that way.



My difficulty is the units physical construction, not something I can just open up on the bench for easy access to things. I did the poking things with a wooden stick routine but once again access is a problem with the unit running. Nothing has jumped out as the source of the problem. I need to measure supply's and trace signals when the thing fails which is kind of like predicting the weather. A schematic would help big time to locate test points, identify connector pin-outs and stuff like that.



I can probably manage to trace things out and track things down but a schematic would save me a lot of time. Does anyone got one?

[Enzo]

perhaps Kustom does, did you call them?

Does it have an FX loop pair of jacks? or a preamp out and power amp in pair? In either case, patch send to return with a spare cable and see if it wakes up.

[Jazz P Bass]

This is what I have on the Profile System: Kustom PA mix 1.pdf

[Sowhat]

This is what I have on the Profile System: [ATTACH]45017[/ATTACH]

Can't seem to read this... just gets interpreted as a 1x1 .gif with my browser. This has happened before, just don't remember what the remedy was.

[Enzo]

It means he needs to repost it in a different format. Nothing to be done on your end.

[Sowhat]

I didn't call them but I emailed our old buddy "parts@kustom.com" and requested one, no answer yet.

Yeah, it has a line in/out patch, didn't try that, I'll give it a go. The way it cuts out and cuts back in just sounds thermal in origin... yes, I hear in degrees of heat! :-0

[Jazz P Bass]

Oopsie.

Here you go: Kustom PA mix 1.zip

[Sowhat]

It was a short day today, just an hour or two. The schematic helped a lot, thanks. So far I can tell you what it ain't. There's a +-66 volt rail, a +-33 volt rail, a +-15 volt rail. 48 volts, 56 volts and 5 volts... (that's a lot of volts there) anyway, they all continue and remain steady after the amp cuts out. Getting these readings was difficult and required me to solder in some taps here and there to clip onto. This System Two uses a STK404-100 amplifier module protected by a C1237HA Stereo Amplifier Protector Circuit. If funny business on the outputs is detected a relay cuts off the amplifier output... this sounds kind of like our culprit. Interesting thing is that if the protection trips you would expect main rail power to the STK404-100 to be cut off as well, but, it's not, only the speaker outputs are disconnected. The STK404-100 however has an internal over temperature cut off so this is what actually shuts down the amplifier when problems arise, not the protection circuit. It should be pretty easy to determine if the STK404-100 protection or the C1237HA protection is causing the cut outs. Anyway, that's the plan for Tuesday morning when I get back to the shop. I think I have narrowed this one down a bit.