Joined: Feb 20, 2012
Posts: 3
From: Meadview, AZ USA
Posted: 2012-02-20 22:01
I'm trying to repair my old receiver, just lost sound, all inputs dead no tuner output. Still sounds like there is slight background noise in headphones, all the relays seem to click on, display works. The orange display lights for bass boost and direct pass, etc. pulsate instead of a steady glow. They pulsate in a kind of pattern, this is odd to me. 5.6v out the AC board although that reg seems very warm. The front panel door will not open/close without much assistance. the motor seems weak. The main amp board large heatsinks get warm after some time and I can adjust the bias currents on each white wire block to 20ma. I think this is good, telling me the main amp part still works? I don't know what to check next, some of those boards are buried deep under other boards. Any ideas? Thanks.
Joined: Mar 13, 2003
Posts: 13823
From: Sewell, NJ
Posted: 2012-02-21 16:03
Welcome to Agoraquest! Unfortunately, I can't help you without the schematics to tell me what the voltages should be. If the orange display is pulsating, that might be a symptom of insufficient voltage to the display.
I found thru a google search and have been using to troubleshoot. I got as far as page 31, the AC board, measuring the voltages there, mainly the 5.6v of Q902 regulator. It's not rock steady, but moves between 5.6 and 5.7. I wonder if the backlite for the buttons (not the flour greenish display) which is orange, is related?
[ This message was edited by: Patman715 on 2012-02-23 15:06 ]
Joined: Mar 13, 2003
Posts: 13823
From: Sewell, NJ
Posted: 2012-02-23 17:45
Thanks for the service manual! The display board schematic is on pages 32 and 33 of the service manual. The display is FL101. AC power is applied to the F1 and F2 terminals. If you trace the A3 and A4 wires that are connected to these terminals, you will see that they are connected to pins 3 and 1 on five pin connector CNE101 shown at the bottom of the drawing. Note that the connector is connected to PTB board connector CNE951. FLV+ on pin 5 of CNE101 provides power to fluorescent tube drivers IC101 and IC101. According to the schematic, its 38.7 VDC. These are the voltages that you need to check. The PTB board schematic is on page 47.
Joined: Feb 20, 2012
Posts: 3
From: Meadview, AZ USA
Posted: 2012-02-25 21:27
Well I fixed it, turned out to be a loose solder connection on the Input board CNE939 near D908 right on the edge of the board. there was no AC voltage going into the bridge rectifrier , thus when I checked for the +/-5V out there was none. All I had to do was remove the bottom cover and touch the solder iron. I really needed the service manual to help this thru and thanks for your help jehill. WUUUWHOOO I'm happy
On 2012-02-25 21:27, Patman715 wrote: WUUUWHOOO I'm happy
A well functioning Sony ES Class receiver will do that for ya'.
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