Re: Denon x1200w Shorted
My experience with these Denons is that usually the emitter resistors and possible some other passive components go bad when the PT is bad. Don't ask me how I know this, BUT if you only replace the transistor it will product a low volume, typically distorted, and eventually pop and smoke on you in a minute or two. You will need to re-test the power transistors for that channel as well as the passive components in that stage. You may also have blown the driver as well, so test back up the channel.
The wonders of amp repair.
Ponc...
Ponchojack
Member
Last Activity: 03-31-2024, 09:17 AM
Joined: 03-08-2020
Location: Ipswich
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Pioneer SX-503s series diagnostics sequence
Anyone out there know the button sequences to run diagnostics/error messages for this series of receivers? I know the sequences for the later AVR receivers.
There is nothing in the service manual. I think I've determined holding the power button down while you plug it in seems to over ride the protection mode since I can hear the relay click, but not sure.
The owner thinks this unit might have been impacted by a lightning strike.....ugh.
Standby power seems fine. Next stop is to disconnect the power amp if I can't find the diag.
Pon... -
Re: Charger circuit to replace Alkaline D-Cells with NIMH AA cells
Stj, thanks for the good idea. I'm going to try it. I'll let you guys know how it goes.
PonchoLeave a comment:
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Re: Charger circuit to replace Alkaline D-Cells with NIMH AA cells
The TP5100 idea is interesting especially if the radio will run on 2 18650 cells. I'll have to hook it up to my PS and see hoe well it works at 8.4 voltsLeave a comment:
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Re: Charger circuit to replace Alkaline D-Cells with NIMH AA cells
Thanks guys fro the quick replies. On the 1.2 vs 15 volt issue. This should not be an issue. Most devices are designed to handle it since traditional D-cells will drop from 1.25 to 1.0 volts over their lifetime. The device is typically designed for the 1.2 volts. NimH tend to frun flat for most of their power curve.
I'm assuming the the 18650 idea would use 3 cells with buck regulator?
I would need to look into the charger. Also not sure how to do the physical fit. The nice part of AA batteries,...Leave a comment:
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Re: Charger circuit to replace Alkaline D-Cells with NIMH AA cells
A first thought.....what about using this smart charger? [url]https://www.banggood.com/Black-Ni-MH-Ni-Cd-Charger-For-Battery-2_4V-3_6V-4_8V-6V-7_2V-8_4V-9_6V-10_8V-12V-p-1640958.html[/url]
Then rewire the EXT power plug in the radio with zener diode to limit voltage to the radio circuitry while the adapter is plugged in charging the batteries.
Will this work?Re: Charger circuit to replace Alkal...ing this smartLeave a comment:
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Charger circuit to replace Alkaline D-Cells with NIMH AA cells
So here's the challenge...........
I have a Grundig radio that uses SIX D-Cell alkaline batteries. A somewhat pricey affair to replace these things when they run out. I can't blame the radio, it sips power and the batteries last a long time. The unit also has a 9V wall wart adapter.
What I want to do is replace the six D-cells with six AA rechargeables using those plastic battery adapters. I have no doubt it will work fine and the batteries will last a respectable amount of time.
I guess I could take the AA batteries out and put them in a charger when... -
Re: Is this a screen defect? LG 39LB5600
Thanks so much for this tip. Did you need to use some sort of glue or did they just reconnect when you pressed them?Leave a comment:
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Re: Is this a screen defect? LG 39LB5600
Yeah, the shadow is a minor reflector issue I can fix, but the rest must be the screen.
Well, I have some replacement boards and a frame with a new LED set of strips if anyone needs them.
PonchoLeave a comment:
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Re: Is this a screen defect? LG 39LB5600
uploader rotated the picture, sorry.Leave a comment:
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Is this a screen defect? LG 39LB5600
I have this TV that seriously burnt an LED strip. It blew out the Main board but the power and t-con boards are ok. (I've swapped them for other good boards) The screen (and scan drive boards) , ribbon cables, and diffuser seem fine and show no visual damage. The screen shows a pattern I've not seen in an LED TV where the top half of the screen is problematic. Attached image.
Any experienced thoughts?
Poncho... -
Re: Denon AVR-E300 in DC Protect Mode
Looks like one channel has a blown base resistor. What else usually goes? Nothing obvious yet, I'll have to dig deeper.Leave a comment:
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Re: Denon AVR-E300 in DC Protect Mode
Ok, maybe this will work. I can see the main board and schematic show pins for setting measuring the MV to bias each channel. Pin 2 is connected to the output for the last stage of each channel (image attached). I'm assuming you measure for DC voltage between this pin and chassis ground?...Leave a comment:
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Denon AVR-E300 in DC Protect Mode
I've started troubleshooting this issue. I've cleared the code and it resets the error. Trying to figure out an approach. Looking for DC voltage in the output would seem the right move. First, determining which channel Front or Surround. Secondly, where to test? I would usually test the pins on the output relays, but they are on the bottom of the main board. Any idea the best place way to check the output?
I know you can disarm the auto shutdown by removing the harness BM502 between the Main and digital board. I've already inspected the board, tested main caps, and diode tested... -
Re: New Members - please post your introductions here
Just signed in to get some advice. Im a good EE but a novice technician. Looking to get better and more experience at troubleshooting. First challenge is a receiver throwing a DC protect fault. Always good to get adice before blowing things up.Leave a comment:
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