Hafler power amp has one side out. Would like local repair.Series 9300.Approx.10-15 years old.Not used much.Second time to blow.Runs 4, 8om speakers including 2 bose 802,s (no bose controller or eq in system) and 2 REF Kseries 8om speakers.Used as external amplifier to Yamaha home theater amp to drive mains in system.Thanks,Byron Pritchard,Denver colo.

there are two audio amplifier ic. one is damaged change it. it works perfectly

Two things you can do for a 24-year old machine:

1. Replace both motor brushes (Black large plastic Caps on each side
of the Moto Housing). Without these, the motor wouldn't even run.
2. Replace the Worm Gear (the cause of the Rough Loud noises)

Download a copy of the Repair Part List from Kitchenaid.com for
your model KSM90.

Also don't forget to tighten all the screws inside the mixers and use
fresh Kitchenaid Grade Food Grease for all the gears.

0 ohms is a dead short. That's bad unless you're measuring a single conductor end-to-end.

Register and download the SERVICE Manual for free at retrevo.com

http://www.retrevo.com/support/Hafler-9270-Amps-manual/id/23316bh035/t/2/

Did it ever work?

If not, EVERYTHING is on the table as a possible cause. This is a big dumb amp with nothing but a power switch. Perhaps your source is the issue. Or the stereo/mono switch.

If so, what preceded the failure? Did a control get touched? Smoke?

The Hafler could be protecting itself.

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 'naked'. 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.

Check for loose speaker connections at the speaker as a root cause for intermittent shutdown.

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NEVER USE MAXIMUM VOLUME FOR TROUBLESHOOTING.

Turn the SOURCE volume control to something medium.

The errant switch, control or condition may change and you will suddenly release the amp's full power and possibly destroying your speakers. If a signal isn't audible at 1/2 volume it's probably not there.

Carefully examine the front panel for clues like a misplaced Mute or Tape Monitor control or Multichannel Analog Input selected.

There is a good chance that a common control may have developed a high-resistance or 'dead' spot through idleness and is causing your symptom. Turn the POWER OFF and operate every control throughout its range a number of times, especially rarely-used ones like Tape Monitors and the Mute control.

Turn the volume to something reasonable and see if that helped.

Run a wire from the negative side of one speaker to the positive side of the other speaker. Then plug the remaining two wires into the amp. The positive wire coming from the first speaker goes to the positive on the amp on the first channel. Then run the second wire coming from the negative side of the second speaker to the negative side of the second channel on the amp. There for giving you the max power of your amp to your speakers. Hope this was helpful!!!

Dunno how old they are, but I just had an 11-year old pair of woofers re-edged because the foam surround and the adhesive had deteriorated. Upon close inspection the foam surround was noticeably pulled away from the cone in a few spots. Unfortunately, if there is an age-related issue with materials beneath the surface that you can't see, you'd have to pull the driver to check it out.

It wasn't until I turned my bass up loud that anything sounded wrong, which precipitated looking for the culprit (quickly found).

if the speakers are wired in series, if one goes out the other one wont play either. series is when one wire of first speaker goes into amp, then the other wire of first spkr is connected to one of the wires of second spkr, then the other wire of second spkr goes to the other conection on the amp. kinda like forming a chain. use a 1.5v ( AA, AAA, C-CELL)battery to check your speakers. connect one wire to + side and the other to - side of battery. they should move either in or out. if they move they are still ok. this wont cause them any damage. i use this method all the time to check for spkr polarity.

Connect a set of stereo RCA cables from the 'Output 2' on the Hafler to the line imputs on the Sub.Turn on the '1+2' output switch on the Hafler and rock out!

To avoid making the avr go into protect mode when you power up your Hafler 4000 that is connected in the avr's pre-out, you must power up the set up in the correct sequence.

1. Turn off your avr
2. Connect Hafler 4000 to the avr's pre-out it it is not yet connected
3. Turn on your Hafler 4000. The avr will not go into protect mode becasue of the transients from the Hafler because it is still not powered on.
4. Turn on you avr. There should be no more transients from the Hafler at this stage unless it is not functioning correctly, so the avr shouldno longer go into protect mode.

i, trying to hook up a powered subwoofer to my hafler dh 110 and dh 500 running a bose 901 series v active equalizer and series v 901s any info would be appreciated

Sounds like a short circuit or a defect inside the circuitry that is allowing more power to flow through, thus blowing the fuse. My advice would be to dispose of these speakers for safety reasons and invest in a good quality set.