Phd2 amp after repaired seems to lower output

I've got one also, so that's a worry. You mean you have tried all this stuff?

https://support.google.com/googleplay/answer/2668668?hl=en-AU

It seems to be a common problem

http://productforums.google.com/forum/#!topic/mobile/WTxa5xz-5MY

http://forums.androidcentral.com/google-nexus-7-tablet-2012/270069-nexus-7-wont-charge.html

bad amp its getting a bypass voltage to the amp when powered down sell the amp, if it is the grey model email me [email protected] i might buy it

When i hooked up my bass knob the amp made my subs hum i unhook the rca but still humming unhook bass knob still hummin

Hi, You have problem with your alternator ( charger) . Seems the voltage output regulator work failed. You can check the output voltage of alternator by using DC voltmeter and it should read between 12-13.8 VDC. If the reading below that range your alternator is malfunction and need to repair by experience people. Regards

First, swap the speakers to see if it stays with the speaker or the amp channel.

Second, disregard the throretical ability of any speaker to handle any amplifier's maximum output. Amp ratings are at a certain power output with a certain amount of distortion. Turn the volume a click higher and power output might rise just a tad but distortion starts to go ballistic. Continue and you get total high current garbage. Clipping (high DC output) will kill any speaker.

Since it seems to go away, I doubt the speaker is damaged, unless torn speaker cone or burnt voice coil can self-repair in a few minutes every time.

First of all the KEF is a powered sub which means that it wants a line level signal NOT a speaker level. Send the signal from a tape output or pre-amp output to the sub input. The overload is because the impedence load for the speaker output is too low and looks like a short to the amp. Continued attempts to connect the system as described will result in damage to the output section of the amp.

Please let me know if you need more info.

Dan

i would be looking into the input stage of the amp. seeing that amp has a protection circuit if it saw a issue with the output's it would put the amp into protect mode and not let the power supply turn on. so the issue is most likely in the input side of the board . from the symptoms it sounds that way also.

Have a look at one like yours in store & see what specs are on plug in to charge. It will say Output voltage ..., then how many amps, or milli-amps, for example: ( output voltage 13.5 VDC @ 800ma.) Now find a charger/adapter, with same specs, and plug. Perhaps one your using is very minimal output, or lower voltage. Be sure polarity symbol is same on both too.

If possible return the amp to the seller for a refund (before you tamper with it).

If that's not possible, the amp will need to be repaired. Do you want to try to repair it yourself?




For the head unit, you need to check the shield ground first. The following page will show you how to perform the test.

Shield Ground Test/Repair

Let me know if you have any other questions.

It sounds like the output transistors have failed. Disconnect all of the speakers from the amp and power it up. If it still goes into protection, an output has almost certainly failed.

 

To repair it yourself, you'd have to find the defective one, purchase the replacement parts and replace the parts in the circuit board. 

 

This type of damage is often caused by driving an ohm load lower than that recommended by the manufacturer.