Hi,
my friend asked to look at the amplifier. Amp model is Pioneer VSX-527-K.
First symptom was no power or standby.
Found few faulty components from AMP5 Assy: transistors Q404 (2SD2390), Q410 (2SB1560), resistors R430 (0R47), R431 (0R47) and R439 (100 ohm). All belongs to Front Left Channel.
Purchased transistors from eBay (from France). Soldered new components and reapplied thermal paste to heatsink. After it amplifier starts and can hear music ok from right speaker but left speaker has distorted and lower sound than right..
Checked...
Thank you to the guys at HEGE supporting Badcaps [ HEGE ] [ HEGE DEX Chart ]
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Pioneer VSX-527-K distorted audio after replacing parts
Last edited by tietoharrastelija; 02-01-2023, 11:34 AM.
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HP Probook 4520s Administrator password reset
Hi,
got HP Probook 4520s laptop. Works ok, but can't enter bios because it asks Administrator password. Boot from HDD or USB is allowed.
Tried:
HPBR - Result: Not supported notebook
FPTW - Can dump but no re-flash... (Error 280 Failed to disable write protection for the BIOS space)
SMC.BIN (HP no longer creates these files)
Short Method: [url]https://superuser.com/questions/1108228/remove-bios-password-for-hp-probook-4530s-reset-bios[/url] (Not worked)
RCUnlocker (Created unlocked file from bios dump but can't flash with FPTW (error...
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Re: LG 50PM670S no image
Maybe EAX64300301 burned, looks like one of it ic has bright spot on top when power is on tv..
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Re: LG 50PM670S no image
Tested almost all caps on y sus board:
C204: 25V 330uf 0.35 ohm 346 uf
C201: 25V 330uf 0.37 ohm 343 uf
C102 25V 330uf 0.35 ohm 345 uf
C251: 250V 47uf 0.49 ohm 49 uf
C264: 250V 47uf 0.44 ohm 49 uf
C257: 200V 47uf 0.58 ohm 46.58 uf
C303: 250V 10uf 1.6 ohm 9 uf
C263: 250V 10uf 2.1 ohm 10 uf
C151: 50v 100uf 0.20 ohm 94.07 uf
C213: 50v 100uf 0.19 ohm 91.03 uf
C209: 50v 22uf 4.5 ohm 21.66uf
C101: 50v 100uf (once replaced) 0.28 ohm 102.4uf
C256: 50v 22uf 6.3 ohm 20.75uf (here's...
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Re: LG 50PM670S no image
Now -vy output about 70v (trimmer not changing) something wierd.. Tested without panel flex cables also (but then Voltage was 0v)
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Re: LG 50PM670S no image
Tested Y buffers for shorts yesterday. Now VA is stable 55v and VS 205v (adjusted trim).
But -VY and VSC voltage now changes strange and show unrealistic voltages, under 100v and over 200v (I have cheap multimeter). Maybe something causes ripple? Some capacitor?...
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Re: LG 50PM670S no image
[url]https://photos.google.com/share/AF1QipNx_tkTzqmQoMyjrKoL6qmbWIpOm9UFKCgNjQ8rychRuKilCHRNL1iyTwcvYj8CHA?key=UEtUU2E3OWMwTTJfMjlPalpMWHpQMW81YURORUdR[/url]
Link to video where green led blinking. (End of video led blinking better, sorry for background noise)Re: LG 50PM670S no image<br /> <br ... led blinking....
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Re: LG 50PM670S no image
Tested that but still no picture.. (used small wire and removed LVDS cable)...
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Re: LG 50PM670S no image
Measured voltages DMM:
-VY = 190v
VSC = 143v
VS = 204v
VA = 54V
VZB = 150V
Are these right? When I plug HDMI cable from computer to TV I heard sound but no picture I touched white square resistor on Y sus board, it was bit warm..
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Re: LG 50PM670S no image
Ah, loose ribbon.
What is correct -VY (I got positive Voltage on multimeter) and +VSC?
I know that VA is 55v and VS 205V
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Re: LG 50PM670S no image
Tested Y Buffers without TV -> no shorted. I put everything back (also screws) and tested. No magic smoke, TV started internally logic board green led and center board led blinking. Also standby goes to on. But still no picture. Yesterday I was turned trimming potentiometer (Maybe VY voltage), changed it yesterday same position but maybe not same position (Can that cause no picture??) How to set it correct position?
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Re: LG 50PM670S no image
Can't find 30F126 from any a reputable supplier. Purchased components from UTSource. 30F126 looks like used (thermalpaste residue on component)......
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Re: LG 50PM670S no image
Looks like Q404 ja Q403 (30F126) again shorted ( 4 ohm and other 14 ohm), replaced again and +VS ja GND now no conductive (infinite resistance)
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Re: LG 50PM670S no image
Tested it few moments ago on table. +VS and center screwholes resistance 413 ohm (DMM 2000 ohm range)....
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Re: LG 50PM670S no image
Can't meter now vy voltage (also turned trim vy) it always on for one second and after it back to standby.. Placed all screws etc.. something shorting (?) but checked..
EDIT: Tested +VS pin (from connector) and groud chassis DMM Said 413 ohm, is that OK?...Last edited by tietoharrastelija; 04-30-2020, 05:32 AM.
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Re: LG 50PM670S no image
Okay, maybe wrong test point for -vy. Found another shorted from diode (replaced it), and checked 4 components for shorts removing them (but false short). TV goes to protect mode (aka goes to standby one second when press Power Button). When I place tape under screwhole (3-7) go voltages and TV powers on. But without tape and screws it sparkling. Mysterious problem.....
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Re: LG 50PM670S no image
Found another problem from Y Sus board.
Can place screws only 1 and 2 screwholes and tighten. When trying place screw or tighten screwhole 3-7 tv not start (only standby led off for few seconds).
Screwholes 6 and 7 have small crack around hole. Tried place screw to hole 4 and got sparks. (holes shorting (?)) they are ground points to chassis??
(See photos)...
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Re: LG 50PM670S no image
ZSUB board voltage capacitor etc is 15v IS that correct?...
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Re: LG 50PM670S no image
Tested, but not doing anything.
D101 green led still blinking like something code (one long, and few short)
EDIT: Sound working OK via HDMi...Last edited by tietoharrastelija; 04-29-2020, 05:06 AM.
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