Forum: Troubleshooting Audio Equipment
Today, 12:35 AM
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Replies: 1
Views: 175
Re: ONKYO TX-SR607 ; FL Tube LCD Replacement ?
It is common to have bad solder joints at the tube because the pins are made of Kovar and do not solder easily. Or the power transformer pins have bad solder connections, or at the middle board.
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Forum: General Electronics Technical Discussion
Today, 12:08 AM
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Replies: 14
Views: 227
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Forum: General Electronics Technical Discussion
02-24-2021, 03:17 PM
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Replies: 4
Views: 172
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Forum: General Electronics Technical Discussion
02-22-2021, 01:57 AM
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Replies: 11
Views: 223
Re: Whats this ripple?
The ringing I don't think is much of a problem.
It's the low 3.3V drive to the mosfet. IRF510N (https://www.vishay.com/docs/91015/sihf510.pdf) would really like at least 5V gate-drive to turn on to...
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Forum: General Electronics Technical Discussion
02-22-2021, 12:32 AM
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Replies: 7
Views: 292
Re: Testing for short circuit in diode mode
Older digital multimeters had "low power ohms" that apply under 0.4V which keeps diodes and most semiconductors off, allowing you to make ohms measurements in-circuit.
You would use both with...
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Forum: General Electronics Technical Discussion
02-20-2021, 01:44 PM
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Replies: 11
Views: 193
Re: Help Identify this Fuse
Post a picture of the part that is the "fuse LBV160". Without the bblluuurrr.
It seems to be a custom British Standard multimeter made by Caltek HK.
I call a polyfuse a PTC, the big yellow...
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Forum: General Electronics Technical Discussion
02-20-2021, 01:17 AM
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Replies: 11
Views: 193
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Forum: General Electronics Technical Discussion
02-20-2021, 01:02 AM
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Replies: 11
Views: 223
Re: Whats this ripple?
What you are seeing is called "ringing", like when you tap something resonant like a bell, it oscillates at a frequency while the amplitude fades out.
There are many resonances in electronic...
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Forum: Troubleshooting Game Consoles & Other Weird Devices
02-18-2021, 02:33 PM
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Replies: 9
Views: 426
Re: Kitchenaid food processor burnt wire
Gently scrape off the melted plastic from the relay terminal and I would put on a new crimp connector, something not from china where the metal is thin-not copper, plating is crap and the spring is...
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Forum: General Electronics Technical Discussion
02-17-2021, 07:50 PM
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Replies: 43
Views: 2,498
Re: Help identify a Zener?
Chamberlain Liftmaster garage door sensor 14LG372-1B I have not seen you'd have to post some pictures.
The black IR receiver module runs to 5.5V max (plus a diode drop) so the zener needs to be...
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Forum: General Electronics Technical Discussion
02-16-2021, 01:44 PM
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Replies: 18
Views: 262
Re: Valliant boiler board
On the second board I see capacitor C708 bent over, hopefully not mashed. It's by the big filter cap/relay at the edge.
Did you clean the flame rod? Common problem here is boiler controller goes...
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Forum: General Electronics Technical Discussion
02-15-2021, 11:16 PM
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Replies: 18
Views: 262
Re: Valliant boiler board
The board shows water damage, rust on the pcb. Something leaked on it.
I would clean it up with isopropyl alcohol and an old toothbrush, gently.
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Forum: Troubleshooting & Designing Networks
02-13-2021, 03:12 PM
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Replies: 23
Views: 836
Re: Packet loss on LAN...
I've had either the 12V wall-wart caps or the switch's internal electrolytic caps go bad. I'd take a look at them.
A new one is cheap but these things run hot they don't last more than a couple...
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Forum: General Electronics Technical Discussion
02-13-2021, 03:07 PM
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Replies: 9
Views: 445
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Forum: Troubleshooting Game Consoles & Other Weird Devices
02-13-2021, 02:36 PM
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Replies: 16
Views: 597
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Forum: Troubleshooting Game Consoles & Other Weird Devices
02-09-2021, 05:39 PM
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Replies: 12
Views: 687
Re: Crucial M4 SSD failure?
I wonder if a MLCC capcitor has shorted? The clicking would be one of the buck-converters trying to power up into a short circuit.
I would try to power up the board and you can measure the power...
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Forum: General Electronics Technical Discussion
02-08-2021, 05:40 PM
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Replies: 6
Views: 237
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Forum: General Electronics Technical Discussion
02-08-2021, 04:26 PM
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Replies: 6
Views: 237
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Forum: General Electronics Technical Discussion
02-08-2021, 02:41 PM
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Replies: 6
Views: 237
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Forum: Troubleshooting Game Consoles & Other Weird Devices
02-08-2021, 12:12 AM
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Replies: 12
Views: 687
Re: Crucial M4 SSD failure?
I have many problems with USB3 cables breaking off the enclosure pc board.
Try a new cable, they are very fragile. Then look at the connector on the USB enclosure board. Not the SSD drive.
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Forum: General Electronics Technical Discussion
02-08-2021, 12:09 AM
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Replies: 9
Views: 445
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Forum: Troubleshooting Audio Equipment
02-07-2021, 05:30 PM
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Replies: 24
Views: 419
Re: D718 & B688 Transistors - Substitutes?
The Technics design looks good, worth restoring. New stuff is so cheap and sounds terrible, hard pressed to use five transistors per channel and overheats.
The FET phono preamp is nice, I would put...
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Forum: Troubleshooting Audio Equipment
02-07-2021, 01:52 PM
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Replies: 24
Views: 419
Re: D718 & B688 Transistors - Substitutes?
I was going to say that seems suspiciously low offset V - is the protection relay clicking in? I would expect 5-50mV at the output and what do you measure on the other side of the 1k resistors?
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Forum: General Electronics Technical Discussion
02-06-2021, 03:19 PM
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Replies: 6
Views: 236
Re: Battery Charging Peugot Boxer
The fuse was blown?
I've read there is a red button near the ignition switch to disconnect the battery (-) in the event the vehicle is sitting in storage.
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Forum: Troubleshooting Audio Equipment
02-06-2021, 03:15 PM
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Replies: 24
Views: 419
Re: D718 & B688 Transistors - Substitutes?
You have Q507/Q503 on the heatsink label but schematic says the output transistor pair is Q507/Q509. Q503/Q505 is the driver stage.
I would look for side effects from the O/P transistors shorting....
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