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Old 4th August 2009, 02:37 AM   #21
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Default he he he

I also have original and cloned S/550E.
My PCB that I shown was made my me but I put it in original S/550E substitute which one broken from SPARK !

Does anyone interested this completed PCB ?

Thanks
Anadigit
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Old 6th August 2009, 07:32 AM   #22
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Default Could use some more advise please!!

Hey everyone, while waiting on getting my new (to me) ML Ascents fixed, whole other story, anyway, I decided to go ahead and remove the "good" channel from my S-500 to remove and replace thermal compound between outputs and sinks. Much to my surprise when checking the outputs I found an "N" with a dead shorted EB junction!!! And I mean dead short, 0.6 ohms!!! This channel still worked, on scope it worked as well as the repaired channel, exact same AC output voltage when driving 8 ohm loads just below clip!!! I checked this after fixin the obviously blown channel. Not blowing rail fuse. Perfectly symetrical clipping of both channels. Anyone ever see this? I've never repaired an amp, any amp, that would still work with one output with a dead shorted EB juction on an output. All 0.1 ohm emitter resistors ok. None open. Reccomendations anyone for next step of troubleshooting? Have some time as getting order together for Mouser, etc, as I now need some more 15024 & 5's to pick thru.

Thanks in advance, Stevie
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Old 29th January 2010, 02:41 AM   #23
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Default S/550E for PA

This's my S/550E with PA version I cloned PCB from my S/550E last year but I changed supply rails to DUAL SMPS MODULE.

Thanks
Anadigit
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File Type: jpg 550_1.jpg (66.1 KB, 194 views)
File Type: jpg 550_2.jpg (73.5 KB, 190 views)
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Old 29th January 2010, 07:33 AM   #24
a.wayne is offline a.wayne  United States
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Hello Guys ,
Is the bias voltages the same on Series 1 and Series II ? one of my 500's series II , never get's beyond warm at low to moderate levels and stays cold if left idling .

regards,
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Old 29th January 2010, 09:06 PM   #25
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Hi a.wayne, I've tried twice to post a reply to you, email me at steveandvic@sbcglobal.net and I'll try again. Steve
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Old 29th January 2010, 09:13 PM   #26
a.wayne is offline a.wayne  United States
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Will do ....
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Old 29th January 2010, 11:16 PM   #27
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Quote:
Originally Posted by stevieg123 View Post
I found an "N" with a dead shorted EB junction!!! And I mean dead short, 0.6 ohms!
You are certain that you are not simply measuring the PN
junction? Many voltmeters read that as .6 or .7 ohms.

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Old 30th January 2010, 06:27 AM   #28
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Hey Nelson, are you talking my old post where I found a shorted output on the working channel? Steve
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Old 30th January 2010, 04:17 PM   #29
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Yes.

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