Re: Harman Kardon AVR 370
Depends what you mean by "immediately turns off".
Check capacitor C983 and C939, they seem to fail fairly regular. Without any more specific details its hard to say.
bluebear
Senior Member
Last Activity: 07-29-2023, 06:06 AM
Joined: 02-02-2010
Location: Sweden
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Last edited by bluebear; 04-10-2020, 01:39 PM. -
Re: Harman Kardon AVR 270 Buzzing inductor
I have tried with to different sets, 3 speakers and 5 speakers. I did notice the annoying hum, could hear it across the room. With 5 it shutdown on -17dB.
When looking at the photo, I notice some gunk in the inductor case, hmm.
Cheers, B....Last edited by bluebear; 03-22-2020, 03:22 AM.Leave a comment:
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Re: Harman Kardon AVR 270 Buzzing inductor
Sry, I was'nt clear that it was on the last picture, mounted on the frame.
It is filed as a inductor PFC in the service manual.
Cheers,
B....Leave a comment:
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Harman Kardon AVR 270 Buzzing inductor
Hi
I´m trying to find why my HK AVR 270 shuts down with 5 speakers hooked up and increasing volume to about -17dB.
I´ve noticed that a buzz is coming from the unit, not the speakers, and increases when volume is turned up. The humming is annoyingly noticeable. Opened it up and I´m fairly certain that its coming from the inductor CLZ9Z148Z, attached with leads to the primary side CN91 connector.
C983 and C984 as previously been replaced.
How regular is it that inductors fail and would it manifest in this kind of way?
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Re: Harman Kardon AVR 460 DC Offset
Measured again on channel leads and got a different result (sloppy measuring probably):
Center 2.93 V
Surr L -2.968 V
Surr R 1.38 V
SBL -0.12 V
SBR -0.024 V
Front L -0.5 V
Front R -1.297 V
Also measured the Collector on the output transistors to see if they were off the corresponding voltage as measured above.
Center collector pins: -46,62 and 46,50
Surr L collector pins: -46,46 and 46,29
So it does not seem that they are out of balance like...Last edited by bluebear; 02-16-2020, 11:28 AM.Leave a comment:
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Re: Harman Kardon AVR 460 DC Offset
Hi
I checked the mains from transformer, though semi-complete. Missing HDMI-board but powered on.
Measured BN96 from the main transformer board, see attachment.
Service manual is not quiet clear, two values are stated on different boards.
Pin Measured Should be
1 - 26.05 V -17, -20
3 25.23 V 17, 20
9 17.43 V 15 V...Last edited by bluebear; 02-15-2020, 07:50 AM.Leave a comment:
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Harman Kardon AVR 460 DC Offset
Hi
Background:
This unit suffered from high voltage, 27 V, on the surround Left channel. This triggered the protect circuit, as its supposed to, after start up.
After disassembly I checked the Power transistors Sanken B1560 and D 2390 and measured all channels. Found one B1560 broken.
Also the corresponding large dual ceramic resistor 0.27 Ohm had one resistor shut.
Problem:
Even though the 27 V offset value has been reduced I still have DC Offset on nearly all, including the one repaired. Occasionally the protect mode hits... -
Re: FSP AU-500 Aurum series
@PeteS in CA
Recapping secondary side seemed to fix it, but degraded to random restarts and now fan twitching or short power on cycle. Atleast long enough to read the different rails.
Thanks for your suggestion it would seem to be this reason. Just annoying with intermittent or kindof working when probing. Cheers, Bluebear.Leave a comment:
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Re: FSP AU-500 Aurum series
This project semi stalled as I moved on to others. To "recap", all capacitors on the secondary side was replaced with nippon-chemicon/Rubycon including the small IC caps for the two FSP chips.
Had a short test run and it worked really well with stable voltages and powered on every time. I shelved it as a good replacement for later use.
Success? No.
I tried it today for a secondary machine and i behaves like before. Twitching fan, when it powers on its usually not for long.
Measured voltages: ...Leave a comment:
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Re: Panasonic P50G20E
The new board finally arrived, installed it this morning and works great.
I used a board from a P50GW20. Thanks tw2005 for all help.Leave a comment:
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Re: Panasonic P50G20E
@tw2005
I jumped on a similar board for the P50gw20,
for a reasonable price. Could not find much info but seems to be very close to mine. Often also referred to as p50gw20e. The difference is, I hope, that it has a secondery dvb-s board. I have an external dvb reciever anyways, only need hdmi. I Will post when its due. Thanks for the help so far.Last edited by bluebear; 06-01-2016, 09:10 AM.Leave a comment:
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Re: Panasonic P50G20E
Yeah, you are right. I will see what i can find.Leave a comment:
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Re: Panasonic P50G20E
@tw2005
Wow, thanks. Would be an interesting task. You have done some serious digging in the matter.
I´ll see what comes up in regards to the boards. At the moment it works
kind of all the time. When it starts scrolling a simple restart at the unit fixes it and usually works for hours, 1 restart yesterday. The backpanel is restricting air flow due to the small holes. Could be if opened completely it would not restart at all.Leave a comment:
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Re: Panasonic P50G20E
Thank you tw2005, I've seen that thread before.
So basically, it would be possible to swap the HYNIX chip from my P50G20E board to a P50G20B board. That would eliminate the fan problem I assume.
Or just resistor mod the fan connectors and be done with it.Leave a comment:
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Re: Panasonic P50G20E
Short update.
Still having the same problem, but now it runs for hour, rather than minutes.
Perhaps I need to increase the fans to keep it cool enough.
tw2005, did you find anything of the P50G20B board?Leave a comment:
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Re: Panasonic P50G20E
Hombre, you are a genius. Had some time to continue testing this evening. Measured the chips and the little one on the a-board where hot to touch. Measured 90 degrees Celsius with my IR thermometer. Tried first with my wife's hair blower with no heating and it worked longer than ever before. Mounted som small DRAM heatsinks if that would help. Nope still to varm.
Then tried a small fan, and voila. It has now stayed on for 1 hour.
Lovely, maybe a short fix we will see. I mounted the fan on the outside of the backpanel and power it...Last edited by bluebear; 05-26-2016, 04:06 PM.Leave a comment:
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Re: Panasonic P50G20E
Ok i Will Hook it off. Aything to consider before unhooking, so I dont damage other parts?Leave a comment:
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Re: Panasonic P50G20E
Would it be any use going at them with a handheld hotair, model cheap?Leave a comment:
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Re: Panasonic P50G20E
Could be an option, though would a different revision work. Seems there are many P50G20B boards for reasonable prices. Not sure what are the differences, seems though that they are not compatible....Leave a comment:
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Re: Panasonic P50G20E
Thanks, maybe a later rework then.
Its not that easy find an A-board for this.
The TXN/A1MFUE on the board I guess is a revision number?
Are these boards interchangeable among the different model numbers?Leave a comment:
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