The H3000 series* Harmonizer Brand special effects processor had a long and fruitful life! From its introduction in 1989 to its discontinuance over a decade later, it was and is one of the most successful audio products ever manufactured. Although it has been superceded by our Eclipse model, there remain thousands of these wonderful units in daily operation. To keep them in operation is this Technote dedicated.
The H3000 is a very complicated, extremely digital device. It uses three DSP processors and a lot of high-speed circuitry. Although there is nothing but common sense to try to stop you from troubleshooting the digital circuitry, please accept our assurance that it is very unlikely that anyone other than a very experienced technician who has worked on these units for many weeks with factory training will likely diagnose and repair subtle defects. Few people with these qualifications are found other than at Eventide. That being said, only a modest percentage of defects fall into this category. The majority of problems are mechanical ones, having to do with connectors rather than defective components. Other user-fixable problems typically involve the audio inputs and outputs.
The following symptoms usually indicate a power connector problem - they typically occur anytime from turn-on to a few minutes later:
| The display backlight varies in intensity or flickers |
| The bypass relay clicks without command or sporadically |
| The display "freezes" or flashes odd messages in non-English characters |
What to do: Scrutinize all the internal power connectors for tightness, cleanliness, discoloration, or other problems. Tighten, reseat, clean, repair, or replace as indicated.
The display indicates, or you believe that the unit's memory and/or presets have been corrupted. The procedure below will "initialize" the unit and erase any user presets.
What to do: Reset the H3000 OS and presets:
| Depress and hold the FUNCTION key while you switch on power. |
| Release the FUNCTION key. |
| When the H3000 displays "REMOVE ALL PRESETS?," press the "YES" softkey. |
| When the H3000 displays "RESET THE OPERATING SYSTEM?," press the "YES" softkey. |
The following symptoms may indicate other loose connections, typically EPROM chips not reliably in their sockets:
| Some presets work, some don't |
| Some presets are missing |
What to do: Reseat any socketed components, especially the EPROMs. Exercise (remove and replace) other internal connectorized circuits.
The following symptoms may indicate defective in/out circuitry. This typically occurs due to previous bad connections to the outside world on which high voltages accidentally were present.
| One input (or output) works, one doesn't |
| One output is very distorted or has a DC bias, the other is fine |
| Other connections (e.g., MIDI) are intermittent or defective while the unit seems to be otherwise OK |
What to do: Carefully look around the connector in question for burnt or cracked components or, in some cases, broken or charred PC traces. Replace or repair as indicated.
Intermittent problems that seem to be related to temperature, e.g., "dies or gets noisy after being on for an hour," are frequently caused by thermally intermittent components. Although these are very difficult to find (for us, too) by normal electronic troubleshooting procedures, there is a simple approach that sometimes can pinpoint the component. There are "freezing sprays" available from many manufacturers that can be used to cool individual components. By judicious use of these products you can frequently isolate a bad component.
Defective or intermittent "Knob." See the associated technote.
| Random noises that occur regardless of circumstance or temperature |
| Crackling or hissing noises that occurs on some or many presets |
| Subtle problems such as unusual distortion, bad frequency response, high noise level |
| Unit unresponsive to control inputs after checking all connectors |
| Unit appears functional but no audio output |
| One channel dead with no obvious analog cause |
| And pretty much anything that doesn't respond to the solutions suggested above |
What to do: Heed your H3000's cry!
*H3000 "series" comprises all model numbers H3000X and H3500X, where X is the model suffix, typically denoting different programming options and appearance. Note that upgrades remain available; more info can be found at our OLDIES link.
This Technote created 15 October 2003