For service, please pack the unit in a box that leaves at least 2 inches for padding, filled with bubblewrap or any other padding material. Ship with any service convenient for you, and I can also arrange for shipment if you provide your address, box dimensions and weight. I will e-mail you a shipping label and can also arrange for pick up by UPS. Dropoffs and pickups in person are welcome in New York City.
Any service/repair/evaluation minimum: $100 plus shipping. I use new components where possible, and have a couple of donor units for parts. My turnaround is usually 1-3 days. Payment via PayPal or check.
I will let you know if there is anything else that needs attention and give you a quote
Includes everything in the Tascam 238 (dbx) full service, excluding dbx-related items, plus rebuild and calibration of the Dolby S noise reduction system.
Diagnosis:
Runaway capstan. No ears or feet. Has been opened before, transport is not
tightly screwed in place. Missing cable tie on the speed control board bundle.
Digital display is dark. Case seems a bit warped.
Capstan board:
Replaced ceramic C2, electrolytical C5, C7, C9, C13, C15, and 9.1V Zener. Still
same symptoms. Investigation turned out corroded ground trace next to pin 1 of
IC1. Created a solder bridge.
Runaway resolved, but speed is uneven with “hiccups”, at a rate of about 5 per second.
Resolved by replacing C16 with a 1uF ceramic.
Lifted and re-soldered IC1 to reduce chance of further corrosion around pads.
Renewed solder joints on R12, C11, C10, R11, C6, R4 and R5.
Washed off flux residue.
Capstan and reel motors are tight.
Checked tape path with a mirror cassette, confirmed alignment of R/P and erase heads.
Calibrated speed in fixed, variable and external modes using calibration tape.
Removed layer of hardened rubber from pinch roller with 1000-grit sandpaper.
Cleaned tape path with isopropyl alcohol.
Power supply board:
Dark display due to two line cracks in the power supply PCB. Resolved by
doubling the traces with PTFE wire. Further cracking is possible.
Checking and calibration:
Verified function with a remote control and footswitch.
Adjusted meters to 0dB/315mV input at 1kHz
Adjusted dbx timing
Adjusted playback level to +3dB at 200nWb/m
Adjusted playback equalizer
Adjusted bias to level frequency response within 2dB
Adjusted recording levels at 0dB/1kHz with DBX out
Adjusted recording levels at 0dB/1kHz with DBX in
Adjusted crosstalk to minimum
Adjusted Sync level