|
|
Post by mastertech on Nov 27, 2014 0:33:36 GMT -5
Well it is not a short to gnd taking out those fuses. You are going to have to test all those output transistors and driver ics to see which ones are blowing the fuses. Don't forget to check the rectifier also.
|
|
|
|
Post by jeremy on Nov 27, 2014 13:04:36 GMT -5
MT, Would C550, C552, and C561 be the cause of the issue? I checked the entire channel and nothing else is bad, I pulled the outputs out and they are fine, the pre drivers are fine, resistors, etc...
So for the heck of it I checked those 3 little caps, and sure enough, both C552 and C561 are open , they don't read at all either direction, C550 starts out at around 30k and keeps counting. Compared those to the other channels and I do get stable readings on those capacitors in the other channels.
|
|
|
|
Post by mastertech on Nov 27, 2014 23:30:11 GMT -5
Well first off, are you checking them with a cap tester?
Second, is ic501 still removed? If yes, this would give you different comparable readings. Also note that only half of ic501 is being used since it is for the center channel. The other pre drivers are using both sides.
Is the rectifier ok?
Were the original fuses 6.3 amp?
Put your DMM on diode scale and test from 1 fuse holder to the other fuse holder on the rectifier side of both and give me the reading.
Then again DMM on diode and test from 1 fuse holder to any pin on rectifier and look for continuity. Then same with other fuse holder to rectifier.
|
|
|
|
Post by jeremy on Nov 28, 2014 23:56:42 GMT -5
Well first off, are you checking them with a cap tester? No, I was testing them on Diode scale, should I test with a cap tester? Mine doesn't do anything besides capacitance and it only tests up to 3300uf. Yep, still removed. I figured it was only being used for just the center. Testing it on Diode scale it appeared to read fine Yes. It starts out around 1.5 and counts to open on the diode scale on the rectifier side testing from one fuse holder to the other. One probe on Fuse Holder F912 on rectifier side, DMM on Diode scale, the - pin reads 1.900 then slows way down and counts very slowly, the ~ pin right next to that one reads short 0.00, the ~ pin next to the positive pin reads open, and the + pin itself reads 0.539 One probe on Fuse Holder F913 on rectifier side, DMM on Diode scale, the - pin again reads around 1.900 then slows way down and counts very slowly, the ~ pin next to it reads open, the ~ pin next to that reads short 0.00, the + pin reads 0.539 |
|
|
|
Post by mastertech on Nov 29, 2014 0:19:22 GMT -5
Well I am not seeing a problem. Does this receiver have an 8ohm/4ohm select, whether it's a manual switch or in the menu? Change it and try power up.
|
|
|
|
Post by jeremy on Nov 29, 2014 0:29:02 GMT -5
Nope, there is no such feature or switch on this receiver. The power transformer wouldn't be causing this would it?
|
|
|
|
Post by mastertech on Nov 29, 2014 11:52:12 GMT -5
No, I am not thinking it is the transformer. I was just seeing that the upper taps are not fused and wondered how it would react engaging that tap.
Since everything seems to be ok in the amp section then there must be something going on past it. But we need to determine which channel it is. Let me look over the schematics some more.
|
|
|
|
Post by mastertech on Nov 29, 2014 12:02:32 GMT -5
I removed CNP920 coming off the main transformer off the mainboard, and the receiver powers up and stays running. I replaced them both, and they both blew again. This part needs to be answered first. If CN920 is connected and the 2 fuses are blown does it stay on? |
|
|
|
Post by jeremy on Nov 29, 2014 13:18:34 GMT -5
I removed CNP920 coming off the main transformer off the mainboard, and the receiver powers up and stays running. I replaced them both, and they both blew again. This part needs to be answered first. If CN920 is connected and the 2 fuses are blown does it stay on? It does not stay on, it still goes into protection even with those fuses blown. |
|
|
|
Post by mastertech on Nov 29, 2014 14:22:45 GMT -5
That kinda does not make since. If it is blowing the fuses it would indicate the low tap is on. If it goes into protect with the fuse blown that indicates the high tap is on. I wonder if that relay is bad. They cannot both be one the same time.
Remove relay RY920 which is after those fuses. See if receiver still goes into protect mode with CNP920 connected. If not then do the following.
Use wire to jump pins 6 to 7 and another wire to jump pins 3 to 4. Replace fuses and try turning on.
|
|
|
|
Post by jeremy on Nov 29, 2014 15:11:28 GMT -5
Will do and get back with the results
|
|
|
|
Post by jeremy on Nov 29, 2014 15:37:35 GMT -5
Removed RY920, replaced the fuses, jumped pin 3 to 4, pin 6 to 7 turned it on and it works
|
|
|
|
Post by mastertech on Nov 29, 2014 15:52:36 GMT -5
So what do you want to do?
|
|
|
|
Post by jeremy on Nov 29, 2014 15:54:06 GMT -5
So what do you want to do? Whatever I have to to get it done  I assume the relay is bad? |
|
|
|
Post by jeremy on Nov 29, 2014 15:55:08 GMT -5
Would it be normal to hear raddling around inside the relay when I shake it? sounds like there's loose parts in it
|
|
I assume the relay is bad?
