His signature is showing at the end of the email threads. Jeff -- Intrepid Video TV/VCR Repair 263 S Front St, Steelton PA 17113 717-939-7708; (F) 717-564-4952 www.intrepid-video.com www.tech-repair.net ----- Original Message ----- From: "becyn" <becyn@xxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Tuesday, November 30, 2004 1:39 PM Subject: [TechAssist] Re: Aiwa ADV58u amplifier-tuner , no sound Well, larry... Still no sig file???? why don't you just type it in until you get the thing to do it automatically,...or ...well...you know the rules...;-) Sincerely, See sig file below! Jim McVey McVey Alltronix 327 Broadway Newburgh N.Y. 12550 Factory authorized service for over 20 major brands. 845 561 8383 larry wrote: >thank you again, jim. >good question, why isnt my name and address at the bottom. >i dont know >it was on the original i sent. >i checked and my signature file is supposed to be at the very >bottom. >so i hope it works this time. >Now on the stereo. >i am slowly learning, i think. >i was confused on which ground to use for the voltage >measurements, but now think i got it. >on all 5 push/pull 2 transistor output circuits, i read the >same voltages, -22 on one collector and +23 on the other >collector and zero volts on the junction of the 2 emitter >resistors for each of the 5 sets of outputs. >so , in my opinion i see nothing wrong there. >also no ohm meter shorts between the output transistor pins of >any of the 10 output transistors. >the tuning meter shows signal, but no audio on any of the 5 >output channels. >what do i check next?? >Larry > > > >becyn wrote: > > >>the relay has nothing to do with the voltages seen on the amp board. it >>only disconnects/connects the the amp output to the speaker terminals. >>( By the way you dont need any loads hooked up to start the process) DO >>NOT UNDER ANY CIRCUMSTANCES ENGAGE THE PROTECT RELAY IF LOADS ARE >>ATTACTCHED!!!!! This will damgage the loads and do furher damage (ie; >>smoke, flame) to the amp >> >>I dont understand what you mean by "no voltage on the junctions". You >>mean that literally? As in no Vcc or Vee or just no offset at the >>emitter swamping resistors? (low ohm ceramics)? >>Perhaps it's as simple as open fuses in the power supply? >>You need to be very precise in describing the voltages otherwise I can't >>make head nor tails of it. >>A normal fail mode is : 1) unit powers up, but no audio out >> 2) all voltages present at amp and >>everywhere else, but a DC offset of 1volt or more can be measured at >>the power amp's output connection. (you must measure it at the pcb) >>You might have something else, especially if you really don't see ANY >>voltages at the amp, but you're gonna have to do some >>troubleshooting...or send it to ME for repair!! ;-) >>By the way, whats your company name and address? I'm surprised that >>Jeff didn't get on you about this! >> >>Jim McVey >>McVey Alltronix >>327 Broadway >>Newburgh N.Y. 12550 >> >>Factory authorized >>service for over 20 >>major brands. >>845 561 8383 >> >>larry wrote: >> >> >> >> >>>thank you for the advice. >>>I do mostly tv repair but fix a few audio, now and then. >>>most the time i can check the collectors and find a short or >>>see burnt resistors. >>>but this time none of the 5 output transistors have a short >>>and no burnt resistors. >>>i have no voltage on the junctions of the transistors, where >>>the outputs are connected. >>>but i doubt i would, because the relay never closes. >>>the power supply has normal voltage to the relay. >>>i am afraid to manually close the relay. >>>what is my next step? >>>Thank you, >>>Larry >>> >>> >>> >>> >>>becyn wrote: >>> >>> >>> >>> >>> >>>>Are amps new to you? >>>>IF you have voltages and no output, the thing is in protect mode which >>>>kicks in if a dc voltage is dectected on the amp out node. Otherwise, >>>>the speaker would burst into flames-(not good ;-) >>>> >>>>No doubt one (or more) of the amps have a dc offset caused by shorted >>>>output transistor, drivers or problem with the differential amp. happy >>>>hunting... >>>> >>>>Jim McVey >>>>McVey Alltronix >>>>327 Broadway >>>>Newburgh N.Y. 12550 >>>> >>>>Factory authorized >>>>service for over 20 >>>>major brands. >>>>845 561 8383 >>>> >>>>larry wrote: >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>>>the readout lites, tunes stations, but no sound. >>>>>please , any clues where to start? >>>>>I have plus and minus 45 volts and also 23 volt + and -. >>>>>Larry >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>----------------------------------------------------------------------------- >>>>Lost Password: >>>>http://www.tech-assist.org and select "Login Problems?". >>>>Email Archives: >>>>//www.freelists.org/archives/techassist/ >>>> >>>> >>>> >>>> >>>> >>> >>> >>> >>----------------------------------------------------------------------------- >>Lost Password: >>http://www.tech-assist.org and select "Login Problems?". >>Email Archives: >>//www.freelists.org/archives/techassist/ >> >> >> > > > ----------------------------------------------------------------------------- Lost Password: http://www.tech-assist.org and select "Login Problems?". 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