(818) 244-4440 as@tekmg.com

TEAC A-1250 Reel-to-Reel Tape Deck Repair Guide

The TEAC A-1250 is a classic reel-to-reel tape deck from the 1970s, known for its robust build and 10.5-inch reel capability. Here are common issues and repair tips:

Common Issues & Repair Tips

1. Motor Not Spinning / Slow Speed

Cause:

Dirty speed selector switch, old capacitors, or worn motor bearings.

Fix:

Clean the speed switch (7½/15 ips) with DeoxIT.
Check the motor run capacitor (often a small black cylindrical capacitor near the motor).
Lubricate motor bearings with light oil (e.g., sewing machine oil).

2. Erratic or No Playback Sound (Distortion/Dropouts)

Cause:

Dirty heads, misaligned tape path, or failing capacitors in the audio circuit.

Fix:

Clean heads, capstan, and pinch roller with 99% isopropyl alcohol.
Check rec/play switch for oxidation (clean with DeoxIT).
Verify tape head alignment (azimuth & zenith) using a test tape.

3. Tape Not Moving (Pinch Roller Issues)

Cause:

Hardened or cracked pinch roller, weak solenoid, or sticky mechanism.

Fix:

If the pinch roller is hardened, it may need replacement (or rejuvenate temporarily with rubber conditioner).
Check the solenoid that engages the roller—clean and ensure smooth movement.

4. Fast Forward/Rewind Not Working

Cause:

Worn idler tire, dried grease, or slipping belt.

Fix:

Inspect the idler tire—if glazed or cracked, replace it (or sand lightly for temporary grip).
Clean and re-grease the mechanical linkages with white lithium grease.

5. VU Meters Not Moving

Cause:

Blown fuse, bad meter movement, or faulty amplifier circuit.

Fix:

Check the fuse on the power supply board.
Test the meter circuit with a signal generator (or gently tap the meter to check for stuck needle).

6. Power Supply Issues (No Power, Humming)

Cause:

Failed capacitors, rectifier diodes, or voltage regulator.

Fix:

Replace electrolytic capacitors (especially in the power supply section).
Check diodes for shorts (use a multimeter in diode mode).

General Maintenance Tips

Demagnetize the heads periodically (using a head demagnetizer).
Lubricate moving parts (capstan bearing, motor, guides) with light oil.
Check belts (if any) for wear and replace if stretched or cracked.

Note: Always disconnect power before working on internal components to avoid shock hazards.

Would you like help with a specific issue? Let me know the symptoms, and I can guide you further!

TEAC A-1250 Capacitor Failure Guide

The TEAC A-1250 often experiences capacitor failures due to age (40-50 years old). Below are the most common failing capacitors and their symptoms:

1. Power Supply Section (Most Critical)

C901, C902 - Main filter caps (typically 2200µF 35V or similar)

Symptoms: Hum in audio, weak motor performance, voltage fluctuations.

C903, C904 - Smaller electrolytics near regulator transistors

Symptoms: Intermittent power issues, unstable operation.

2. Motor Run Capacitor (Speed Issues)

C701 - Often 1µF-2.2µF 250V AC motor run capacitor

Symptoms: Motor won't spin, runs slow, or speed fluctuates.

Note: This is a non-polarized AC capacitor — don't replace it with a standard electrolytic!

3. Audio Circuit Capacitors (Sound Problems)

C101-C104 - Coupling caps on input/output (often 1µF-4.7µF electrolytics)

Symptoms: Distorted/noisy audio, weak output, or channel dropouts.

C201-C204 - EQ/recording path caps on PCBs

Symptoms: Muffled highs, uneven frequency response.

4. Control Logic/Solenoid Caps (Mechanical Issues)

C601, C602 - Timing caps for relay/solenoid circuits

Symptoms: Pinch roller won't engage, transport functions erratic.

5. Tape Head Preamp Caps (Hiss/Poor Playback)

Small electrolytics (1µF-10µF) near the playback heads

Symptoms: Excessive hiss, weak signal, or imbalance between channels.

Capacitor Replacement Tips

Use high-quality replacements:
- Low-ESR electrolytics (Nichicon, Panasonic) for power supply
- Film capacitors (WIMA, Panasonic) for audio paths where possible
Check for leaked/bulging caps: Visually inspect for crusty residue or domed tops
Recap the power supply first: This often resolves multiple issues at once

Safety Reminder: Always discharge large caps (like C901/C902) before working on the power supply!

Would you like a specific board location for any of these capacitors? Let me know if you're troubleshooting a particular symptom!