The only brown spots I can see on the PCB are at the leads of the big power resistor on the lower left. That is normal for this amp, that resistor runs hot! Is that it, or did I miss some other spot?
The caps look fine, but they are still the primary suspect. Sometimes parts fail without any noticable physical damage.
The caps look fine, but they are still the primary suspect. Sometimes parts fail without any noticable physical damage.
ebay has a PM840 now!
There is a PM840 on ebay right now:
http://cgi.ebay.com/Soundcraftsmen-...ryZ48700QQssPageNameZWD7VQQrdZ1QQcmdZViewItem
There is a PM840 on ebay right now:
http://cgi.ebay.com/Soundcraftsmen-...ryZ48700QQssPageNameZWD7VQQrdZ1QQcmdZViewItem
Soundraftsmane 900x2 Power supply Help
Greetings and thanks for all the guidance so far.
My 900x2 is running with supply voltages at 102 volts instead of 87. Unfortunately my copy of the schematic does not include the scr board and the power controller/relay board print is unreadable. Anyone have the print for these two boards.
Thanks.
Greetings and thanks for all the guidance so far.
My 900x2 is running with supply voltages at 102 volts instead of 87. Unfortunately my copy of the schematic does not include the scr board and the power controller/relay board print is unreadable. Anyone have the print for these two boards.
Thanks.
My capicitors burned out in my 900x2
does anybody know where i can get the capacitors for the 900x2? i can't seem to find them anywhere... Also, on the top of the capacitors, there are numbers, one is 22 and the other is 13.
not certain where to get these. by the way, i found a guy on the internet who said he sells the orginal schematics for the soundcraftsman amps at http://www.gourmetpa.com/s.html
does anybody know where i can get the capacitors for the 900x2? i can't seem to find them anywhere... Also, on the top of the capacitors, there are numbers, one is 22 and the other is 13.
not certain where to get these. by the way, i found a guy on the internet who said he sells the orginal schematics for the soundcraftsman amps at http://www.gourmetpa.com/s.html
I have 4 PR1800 amps. These are the early production of the model that was later renamed the 900X2 after MTX bought Soundcraftsmen. Some early ones didn't have the later 'soft-start' circuit. The very high inrush current when you first turn them on tends to make the power supply caps explode or is very hard on the caps to say the least. The damaged caps sometimes subsequently blow the regulator SCR.
So anyway I haven't turned on these amps in 5 years; they've been sitting in a stack in my kitchen. Now after reading these posts I'm kind of afraid to turn them on. I do have some really big variacs, but I'm not sure I could power them up slowly to form the caps anyway, since this is a switching-mode power supply. I don't want to have to replace the caps if not necessary. I don't want to have to build a power supply just to form the caps.
Any good advice is appreciated.
So anyway I haven't turned on these amps in 5 years; they've been sitting in a stack in my kitchen. Now after reading these posts I'm kind of afraid to turn them on. I do have some really big variacs, but I'm not sure I could power them up slowly to form the caps anyway, since this is a switching-mode power supply. I don't want to have to replace the caps if not necessary. I don't want to have to build a power supply just to form the caps.
Any good advice is appreciated.
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