In addition to electronic design, I make repairs on professional audio equipment and laboratory equipment.
Among the brands, I have repaired so far, are : AB International, Ambisonics, Amcron, ATC, Audio Precision, BSS, C-Audio, Carver Professional, Cerwin Vega, Chevin Research, Crest, Drawmer, Dynacord, EEA (E2A), Harrison, HH Electronics, JBL, Lab-gruppen, Nexo, NP Elektroakustik, PP, Revox, Rodec, Samson, Soundcraft, Studer, Telefunken and Urei.
Information required for a repair
A requisition number, if you require this on the invoice.
A precise error report:
- A clear description of the symptoms of the fault.
- On what channel, what connectors and under what circumstances the fault was noticed.
- If you know the reason for the fault, for example that the unit has been dropped.
This is a list of some faults, that often can be fixed by the user.
|Unit will not turn on.||
Mains fuse has blown. If the unit has an externally accessible fuse, check that the fuse is OK. If not, replace fuse with a fuse of same type and rating.
Note: The 6.3*32 mm fuses for cars can not be used as mains fuses.
|Power amplifier, overheating.||Insufficient cooling. Check that fan ducts and air filters are free from dust. Otherwise clean very carefully with compressed air.|
|Power amplifier, early protection.||
Too low mains voltage.
Too thin mains wiring.
A unit earlier in the signal chain generates a HF signal. This is sometimes seen if older amplifiers are combined with digital equipment or wireless receivers.
|Battery powered units.||
The battery is flat.
The battery terminals are corroded. Remove the corrosion very carefully with sandpaper. Ultimately, the terminals must be replaced.
The battery does not have connection to the battery terminals. Check that battery is held firmly against the battery terminals.
|Intermittent popping sound from lavaliere microphones.||The microphone wire can be broken inside the microphone. This can be checked by carefully bending the wire close to the microphone. If the wire is broken, contact the microphone manufacturer for repair or replacement.|