|
|
Post by sunnyfl on Aug 21, 2015 13:38:53 GMT -5
Interesting findings here: disconnected J7514 on the FR channel and R7131 on the FL channel, plug the receiver in and it powered up and stayed on. Shut it down and hit the power button, it came on and stayed on again, however I'm still getting that loud hiss on the left channel 130-150mV.
|
|
|
|
Post by sunnyfl on Aug 21, 2015 13:53:25 GMT -5
I'm playing music, no issues besides those 2 disconnections along with the loud hiss(dc off set I guess) at 0 volume from he left channel.
|
|
|
|
Post by sunnyfl on Aug 21, 2015 13:59:10 GMT -5
I Spoke a little too soon. While leaning over the receiver, I felt the heat coming from the heat sink. I guess it's running a lot less efficient with those two disconnections, 22k resistors.
|
|
|
|
Post by sunnyfl on Aug 21, 2015 19:25:56 GMT -5
With that 22k resistor out(r7131) 2SD2390 of the left channel is flaming hot.
|
|
|
|
Post by sunnyfl on Aug 23, 2015 9:43:13 GMT -5
Still going at it, persistence overcomes resistance, swapped out most of the working channel components still no go. Gonna go a level back to some transistors and caps.
|
|
|
|
Post by sunnyfl on Aug 23, 2015 11:53:52 GMT -5
Need help to identify if these readings are correct.
Zener diode D7601 cathode 11.62V anode 11.62V corresponding transistor Q7601 B 0.001V C 11.63V E -0.338V FEEDS Headphone Relay
Zener diode D7602 cathode 11.66V anode -0.201V corresponding transistor Q7602 B 3.209V C -0.200V E -0.316V Feeds Front Left and Right Channels Relay
Zener diode D7603 cathode 11.66V anode -0.207V corresponding transistor Q7603 B 3.129V C -0.197v E -0.314V Feeds Surround Channels Relay
Zener diode D7604 cathode 11.66V anode -0.194V corresponding transistor Q7604 B 3.129v C -0.197v E -0.320V Feeds Center Channel Relay
|
|
|
|
Post by sunnyfl on Aug 24, 2015 20:39:42 GMT -5
I have a full College semester, so I'm not gonna be able to do too much to Betsy(My receiver). However, this is what I found on the Front left channel. Transistor Q7102 has 7 to 8V coming off its base leg while all the other channels are under a volt. I swapped it out with a working channel and still the same thing.
|
|
|
|
Post by mastertech on Aug 24, 2015 21:46:59 GMT -5
Well hopefully after your semester is over you can read through some of the other threads here to see how my giving assistance works. I dropped out of commenting because you just took off going all over the place randomly. Repairing electronics does not work that way. Poking around randomly only results in repairs on a very rare occasion. Good luck in your semester.  |
|
|
|
Post by sunnyfl on Aug 24, 2015 22:52:12 GMT -5
Well, I was kind of like a headless chicken or a ship in the wind with no rudder. I was also trying to give readings, maybe a keen eye may have picked up an anomaly.
|
|
|
|
Post by mastertech on Aug 24, 2015 23:24:51 GMT -5
A keen eye has nothing to do with it. Poke and hope would be more like it. I have no problem helping a headless chicken but the chicken needs to follow what the rooster says and not to be pecking at the other hens. The hens are nothing more then a distraction and will only get you into trouble. hahaha |
|
|
|
Post by sunnyfl on Aug 24, 2015 23:36:23 GMT -5
:-) there has never been wiser words spoken. You sound like a Captain who sails a tight ship, which is respectable and commended. The only way to do things is the right way.
|
|
|
|
Post by sunnyfl on Aug 27, 2015 15:44:50 GMT -5
Ok, I'm possessed by getting this thing working, I finally got it to stay on, Just to make sure I unplugged it like 20 times, and every time it stayed on and has stayed on. I found something interesting, two capacitors in the DC Protection circuit were in backwards C7711 (6.3V 470ohms) and C7713 (6.3V 470ohms), However, Now I have no sound, The relays click on, I plug the headphone in I hear a click, plug them out I hear another click, then the main speaker relays click. Mayday, Mayday, Mayday...humble me ask for help!
Ps, I also noticed that the left channel dc offset is hovering around 20-22 mV from 90-156mV.
|
|
|
|
Post by mastertech on Aug 27, 2015 21:14:38 GMT -5
Did you change those 2 caps or were they that way?
Are all boards, harnesses and components installed or connected?
|
|
|
|
Post by sunnyfl on Aug 27, 2015 21:54:19 GMT -5
I found them that way. And now it's doing the same thing again. red light flashing. I was screwing down the 7805, 7812 and 7912( these are in an all-black plastic casing, no metal tab) to the chassis and that is when the red light of death started again. I willing to start from scratch and follow direction If someone can guide me through this. I have like 40 dollars worth of parts in my Newark cart ready to order, just don't want to over or under order parts.
|
|
|
|
Post by mastertech on Aug 27, 2015 23:11:27 GMT -5
If this is in fact correct then it makes me wonder what else may be incorrect in this unit. If everything is now assembled and we are starting from scratch then give me the current symptoms. I will check back tomorrow. |
|
