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Where can i get push on caps that protect the dials for a hunting scope

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You could always contact the company that made the scope and ask them if you have the option to order replacement caps, otherwise, you might look into calling around to some of you local optic shops. Most stores that specialize in cameras, binoculars, and other related optical devices are very likely to have some of these caps just laying around and may even be willing to give you a couple free of charge. Other than that, you could always consider using condoms like the military. I know it looks kinda funny, but it's waterproof, and definitely get the job done. Like I said though, I would try calling around to some optical retailers. Hope this proves to be useful. Have a great night!

Posted on Nov 24, 2008

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Hi;my Yamaha receiver RX-V 373 will not turn on. No power. No display. It may be that the unit went into protection mode. Can anyone there, help me, restart my unit back to factory condition?

If you have power it should click before protection mode and have a light showing it's in protection mode.
After the transformer there's some resistors that have failed if it's in protection mode normally it's one or two that have failed, you can get the reading of what they should be by testing them

Apr 17, 2016 | Yamaha Audio & Video Receivers

2 Answers

I have a Yamaha rx-v3000 receiver that lately has begun shutting itself off and then I have to keep hitting the power button until it finally stays on again. This may take 20 times of pushing the power...

Maybe a cool-down is what really fixes it, huh?

Generally speaking, an amp attempts to protect itself from heat, shorts, overloads and operator exuberance by refusing to turn on or stay on.

Overloads can be from excessive periods of high output or marginally low impedance loading by the speakers; and shorts would be wiring issues or a speaker blowing up.

You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.

If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.

If it protects immediately on a cool power up you should disconnect the speaker connections and try it 'nekkid'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.

Cost is way out of scope for us to predict.

Aug 21, 2011 | Yamaha RX-V3000 Receiver

1 Answer

I have an Onkyo TX-NR1000. After pushing very hard during a party one night, The Next day my kids turn it on and after it running for about an hour it went into protect mode then shut off. It had a smell...

This unit probably has separate output transistors which could be checked for shorts. I would also look for cracks in any of the transistors or IC's that may have overheated. Don't forget to check the speakers also as one or more of those could have a shorted voice coil that is feeding back to the amp.

Jan 30, 2011 | Audio & Video Receivers

1 Answer

As soon as i turn on my STR-SE391 reciver the protection is on

It is unlikely that the pushing of buttons caused the problem. The protect flashing means that a problem was detected and the system has shutdown to prevent further damage. The most common cause of this is a failure of the output transistors. Plan on a parts cost between $20-$40 for this repair.


Oct 31, 2009 | Sony Audio & Video Receivers

1 Answer

AIWA receiver

This Protection activates if you hook up Unmatched Speakers i.e less or over impedance as required by Aiwa Amp. 2nd reason can be extra speakers attachment.

Aug 04, 2008 | Aiwa AV-D58 Receiver

1 Answer

I have this pioneer receiver model VSXD608 in which when the volume goes below 20db the unit goes in protection and after some time it tries to switch on back but goes to protection again and keeps on...

Check to see that the electrolytic capacitors that are in the output stage circuits and driver stage circuits are not high in ESR.

Check to see that the power supply is in specs. The main electrolytic caps may not be up to specs. To test the power supply it is best to run a load test on it. You will need the proper setup for this.

The supply current to the output stage may be high, and thus causing the protection to turn on. You will need to have the service manual for details.

It is also possible that the speakers are too low impedance, or their crossovers are going defective and causing a miss-match for their loading impedance.

Look with a scope to see that there are no high frequency oscillations in the output of the amp going to the speakers. A common cause of this type of fault are worn de-coupler caps in the bias circuits for the various stages along the signal path.

Check to see that there is no DC out to the speakers with any position of the volume control with no signal going in. The speakers must be disconnected for this test. Do the same with a sine-wave signal from the test generator. 1 kHz is good to use for this test. Use a proper rated 8 ohm dummy load for your amplifier when applying the test signal. Do not put steady strong tone in to your speakers. You will have to refer to the service manual to know the allowable DC offset at the output stage to the speaker terminals. Most consumer amplifiers must be less than 50 mv. The higher end amplifiers are down to less than 10 mv.

It is also good to do a distortion test to see if there is too high a distortion that is causing the protection to trip.

You can also use the dummy load and the audio generator along with the scope to do power handling tests. This gets involved to put over this type of email.

These are only some basic examples of what to check. You will need the service manual, a scope, ESR meter, DVM, audio generator, and distortion analyzer to go through all the tests to find out where the fault is.

Jerry G.

Jul 07, 2008 | Pioneer Audio & Video Receivers

2 Answers

Yamaha RX-V1 Power

Got the same problem and did some searching.
Strange thing is that next day the amp works fine.
This is what I found on

SYMPTOM: The power cannot be turned on, or the protection circuit is activated to turn off the power.
CAUSE: Fluid leakage occurs from the backup capacitor C633 0.047F 5.5V (C662 in the case of RX-V3000/DSP-AX2) on the Function PCB and causes a short with the adjacent components and between patterns, resulting in operation of the protection circuit. Fluid leakage tends to occur with this capacitor particularly with high internal cabinet temperatures, with or without the power on. Often, the leakage is only visible with very careful inspection.

SOLUTION: Two types of backup capacitors are now available with a longer expected service life. When servicing, thoroughly clean the leaked fluid from the PCB and from under any nearby components before replacing the capacitor. There are models other than those mentioned above that use the subject backup capacitor. Check them for fluid leakage and replace the capacitor as needed.
PART(S): Old
Ref. No. Part No. Description Remarks
C633 or
V3860300 ELECTROLYTIC CAP 0.047F/5.5V Vertical type
* VU545000 ELECTROLYTIC CAP 0.047F/5.5V
Horizontal type
Ref. No. Part No. Description Remarks
C633 or
C662 WD294400 ELECTROLYTIC CAP 0.047F/5.5V Vertical type
* WD292000 ELECTROLYTIC CAP 0.047F/5.5V Horizontal type

Nov 29, 2007 | Yamaha RX-V1000 Receiver

3 Answers

Teac stereo receiver model # AGV8520

One or more output channels has dc voltage present or the protection circuit itself is at fault. Protection ckt keeps speaker destroying DC from reaching the speakers. Connect a dc meter before the speaker relay(s) to isolate which channel if any, is bad. The protection ckt has a small value electrolytic cap connected to the power supply that needs to be checked. Small so that as soon as power is turned off the relay(s) release. This cap will fail causing this error. Measure the AC ripple across this cap, over a couple volts, replace. Also this error could be caused by a missing supply. Inspect all heat sinked parts and other parts for bad connections.

Nov 05, 2007 | Teac AG-V8060 Receiver

1 Answer

System protect

I would suspect the protection circuit is bad (bad cap). It worked before??
Find what is driving the speaker protection relay. Replace the small electrolytic caps in that section. Small caps are used so that when the power is removed the relay releases quickly. Or DC is present on one or more of the amps before the relay.

Nov 02, 2007 | Audio & Video Receivers

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