Sony STR-D515

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Lutti1
Neuling

#1 erstellt: 14. Mrz 2006, 11:18

Hallo ! Hab´n Problem mit meinem Receiver.Er Zeigt mir Protect,und sagt nix.Werkstatt sagt:Brauchen dringend Schaltbild.Kann mir da einer helfen?????????
evtl.Antwort an:www.lutti.werne@freenet.de

doc_parasite
Ist häufiger hier

#2 erstellt: 14. Mrz 2006, 11:42

nach Schaltbilder musst du mal am besten googlen

das wird das einfachste sein (oder einfach ma sony anrufen

)

zdz
Neuling

#3 erstellt: 19. Mrz 2006, 14:02

Hallo,
das hier hab ich mal "irgendwo" gefunden, evtl. hilft es dir ja:

Here's a couple things to think about if you're trying to repair a Sony STR-DE or STR-SE type audio reciever that's gone into "Protect" mode -

1. Save yourself a lot of hassle - get the right schematics for the model you are working on! I spent quite a lot of time trying to work between several models' schematics that were "close" and it can be pretty time consuming (and sometimes downright misleading). There are enough similarities to give you the gist but the differences can easily lead astray.

2. Sony's "Protect" mode:
* First off - when you remove power and open the case, make sure you discharge the large electrolytic caps on the main board. They store B+ and B- (that's +60 vdc and -60 vdc for some models!) and can take quite a while to discharge on their own. Don't just short them out with a jumper! I use a small 25 watt, 120v lightbulb in a "pigtail" socket - I like seeing the pretty vanishing glow in the filament.
* Check and compare final stage output transistor pairs.
* Check the driver ICs (like uPCxxxx, STK350-xxx, etc) for correct output voltages.
* Check the Protect circuit itself (usually transistors Q721-Q723 or something near that - see the diagram below) on the main board. It's usually called "DC Offset Det." Each output channel has a fairly simple overload detector circuit that looks at the voltage drop across the large power resistors (like .22 ohms or so) in front of the output transistors. These O.L. detectors are OR'd into the Protect circuit. Normally, the Protect ckt sends about 5.1 vdc to the System Control IC ("Protect In") on the Display Board. If any channel's overload detector turns on it causes the Protect xistor (usually Q723) signal to turn on and switch 0v common (probably gotten from chassis tie-point - see next item) to the System Control IC. That IC puts the system in "Protect" mode and displays it on the front panel display.
* Most of these recievers seem to tie power supply commons to the chassis! They then use the the chassis to distribute the common to several points on the main board. You can tear the system apart, removing most of the boards, and just have the main board, power supply, and display board connected for troubleshooting. Just make sure you jumper together where the main board was electrically tied to the chassis - (look for where it was screwed to the chasis). If you leave the power supply mounted to the chassis you can just use jumper to it.
* Check the 1K emitter resistor for Q722. It's been found to burn open which will result in a false Protect IN signal.
* You can systematically remove the output transistor pairs and the driver ICs to check if the system will reset.

That's about it for now.