Hi,
Looking for help/suggestions.
I've got a Sony PS-2250 that is blowing the 200ma fuse on startup. Running it through my multimeter, it is drawing about 320-340ma for half a second (both 33/45 startup) and then drops to about 100ma after and runs stable. I've replaced all caps and transistors on speed control board and one bad zener and checked all other resistors/diodes. All is good. The thermistor was pulled and seems in spec and working (120 Ohm @ 25C, rise/lower with temp change), but I will order a new one. The encapsulated component (120 Ohm/0.033uf) I think is good and my understanding is this just filters switch noise and not the cause.
I'd rather not just drop in a 400ma fuse and find a better fix.
Would anybody have an idea?
Looking for help/suggestions.
I've got a Sony PS-2250 that is blowing the 200ma fuse on startup. Running it through my multimeter, it is drawing about 320-340ma for half a second (both 33/45 startup) and then drops to about 100ma after and runs stable. I've replaced all caps and transistors on speed control board and one bad zener and checked all other resistors/diodes. All is good. The thermistor was pulled and seems in spec and working (120 Ohm @ 25C, rise/lower with temp change), but I will order a new one. The encapsulated component (120 Ohm/0.033uf) I think is good and my understanding is this just filters switch noise and not the cause.
I'd rather not just drop in a 400ma fuse and find a better fix.
Would anybody have an idea?
Are you using fast fuses (F) while they should be slow (T) or even slow with a high I2t rating? Does everything work normally except for the blown up fuses?
The SM doesn't mention slow blow fuses, and I did not find anything about using them with the TT. It would be a fallback plan. Everything else seems to be fine now with the table, and after testing through multimeter, I popped in a 500ma fuse I had on hand to test with until I get a slow blow or a better solution. The power transistors seems fine, but wonder if it could be the cause? I have pulled, tested and redid thermal paste when reinstalled.
I think I have my answer.
While the SM did not mention slow blow, on the chassis it is marked 200 mAT, so I take the T to be time delay which makes sense for the behaviour I'm seeing. Happy not to need worry about using them now.
While the SM did not mention slow blow, on the chassis it is marked 200 mAT, so I take the T to be time delay which makes sense for the behaviour I'm seeing. Happy not to need worry about using them now.
