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shp1 amp again (possible transformer)
Posted: Sat Dec 02, 2006 9:50 pm
by lionheart73
well i replaced the 2 caps in the power supply section, after doing so on of the diodeds in the power supply went, so i replaced that, and now my transformer appears to be shorting to ground. Any one know what the values on the power transformer supposed to be?
the amp is almost completely rebuilt, (resistors, disc - mylar and the 2 1500uF are the only things left to replace)
Posted: Sun Dec 03, 2006 1:59 am
by tonymillerus
Why did you replace the capacitors? If it didn't blow the diodes before and does now, I would think you have not connected things correctly. Try contacting a Seeburg repairman such as one of those listed on my site:
http://home.pacbell.net/fmillera/need_help.htm
Any one of them should be able to sort it out for you.
Cheers,
Tony Miller
Posted: Sun Dec 03, 2006 2:31 am
by lionheart73
I replaced the caps per suggestion, and because i thought it might help eliminate the enitial surge through the amp (initial boom when you turn the juke on, also thinking that maybe that was causing the sos to trip)
when i initially put the caps in, i accedentaly reversed one, due to the quality of the schematic and that is what caused the one diode to short out. and when measuring on the secondary of the transformer i'm now finding a short to ground. (when i initially recieved the amp it was in rough shape)
Thanks
David
Posted: Sun Dec 03, 2006 3:39 am
by tonymillerus
The thump you heard is a normal thing with this amplifier when you first turn it on. It happens until the output circuit stabilizes. Drawing too much current would be the reason the SOS trips. Could be a short in the connections to the speakers or bad 1500 uF capacitors or a problem in the bias circuit.
Cheers,
Tony Miller
Posted: Sun Dec 03, 2006 4:19 am
by lionheart73
wasn't sure about the thump, but good to know it's normal, i'll check the bias circuit once i get a new transformer for it. I'll have to find replacements for the 1500uF caps, they are hard to find.
Posted: Mon Dec 04, 2006 7:13 am
by Record-changer
You probably blew more than one diode.
Posted: Sat Dec 16, 2006 5:48 pm
by jukedoc
good afternoon it would be unusal for the transfromer to be shorted I have repaired thousands of the seeburg SHP amps, they are very unforgiving when parts are shorted or reversed on installion my advice to you would be remove all of the output transisitor and disconnect driver cba then get the power supply working both pos and neg before going any futher. after the power supply works connect the drive cba and check voltages if ok check output transisitors for E-C short before reinstalling. if you need more help phone me at 1-877-SEEBURG m-f 9am to 5pm.