FIRST, THIS IS A CRITICAL STEP. IF YOU DO NOT DO THIS STEP, FORGET ABOUT RESTORATION. HARD STARTING ANY OLD ELECTRONICS CAN DO IRREVERSIBLE DAMAGE TO CRITICAL PARTS, OR TO YOU.
THERE ARE SEVERAL WAYS TO DO THIS. THIS IS WHAT WORKS FOR ME. IT MAY NOT WORK FOR YOU. I AM ONLY COVERING USING A VARIAC. THERE ARE OTHER SITES THAT DISCUSS THE DIM BULB METHOD. YOU ALSO NEED AN ISOLATION TRANSFORMER.
1. REMOVE THE PLATE CAP LEAD FROM THE HORIZONTAL OUTPUT TUBE. IF YOUR TUBE DOESN'T HAVE A PLATE CAP, REMOVE THE TUBE AND CONNECT THE FILAMENTS ONLY WITH CLIP LEADS. WE DO NOT WANT HIGH VOLTAGE ENABLED AT THIS POINT.
2. PLUG THE SET IN TO THE VARIAC, THEN PLUG THE VARIAC IN TO THE ISOLATION TRANSFORMER.
3. MAKE SURE THE VARIAC IS SET AT ZERO. NOW, PLUG IN THE ISOLATION TRANSFORMER AND POWER UP.
4. TURN ON THE SET AND SET THE VARIAC FOR ABOUT 50% POWER. LEAVE IT THERE FOR ABOUT 15 TO 30 MINUTES. I RAISE VOLTAGE BY FIVE VOLTS EVERY 15-20 MINUTES. IF YOU SEE ANY SIGNS OF TROUBLE, POWER DOWN IMMEDIATELY. DO NOT LEAVE THIS SETUP UNATTENDED FOR ANY REASON.
DURING THIS STAGE I LOOK FOR ANY OF THE FOLLOWING:
SMOKE: THIS IS BAD.
FIRE: NOT GOOD EITHER. YOU DO HAVE A FIRE EXTINGUISHER RATED FOR ELECTRICAL FIRES, RIGHT?
FRYING OR HISSING SOUNDS. IT COULD BE AN ELECTROLYTIC OVERHEATING OR A BAD POWER TRANSFORMER. THIS IS MORE LIKELY AT HIGHER VOLTAGES, BUT CAN HAPPEN ANYTIME.
TUBES GLOWING RED OR BLUE. BLUE GLOW MAY MEAN THE TUBE IS GASSY. IF A TUBE IS REDPLATING, SHUT DOWN IMMEDIATELY. A FIREWORKS LOOKING DISPLAY INSIDE A TUBE IS ALSO A BAD SIGN.
OVERLY WARM OR HOT ELECTROLYTIC CANS. CANS CAN GET WARM IF THEY ARE CLOSE TO TUBES. IF THEY GET HOT, ESPECIALLY AT LOWER VOLTAGES, THIS IS BAD. POWER DOWN AND RECAP.
OVERLY HOT POWER TRANSFORMER. THIS CAN BE FROM BAD LYTICS, SHORTED RECTIFIERS (IF IT DOESN'T BLOW THE FUSE IN YOUR VARIAC). REGARDLESS, IF THIS IS THE CASE, YOU NEED TO FIND OUT WHY.
NOTHING. ONCE YOU GET TO THE HIGHER VOLTAGES, YOU SHOULD SEE SIGNS OF LIFE. YOU DID CHECK FUSES, RIGHT? YOU MAY HAVE A BAD DOUBLER CAP. I USE THE TOP CAP LEAD WITH MY VOLTMETER TO MEASURE VOLTAGES IN THESE CONDITIONS.
5. AT AROUND 60-70 VOLTS, YOU SHOULD START HEARING NOISE FROM THE LOUDSPEAKER.
6. AT AROUND 80-90 VOLTS YOU MAY START RECEIVING YOUR SIGNAL SOURCE, OR STATIONS IF USING A DTV BOX.
7. ONCE YOU GET TO FULL VOLTAGE, YOU SHOULD HAVE GOOD SOUND AND A STRONG SIGNAL. AT THIS POINT, I POWER DOWN, REMOVE MY VOLTMETER AND RECONNECT THE TOP CAP (OR REINSTALL) THE HORIZONTAL OUTPUT TUBE. ONCE YOU POWER BACK UP, YOU MAY GET A PICTURE. DON'T BE SURPRISED IF YOU DON'T. IF YOU SEE ANYTHING LISTED ABOVE, POWER DOWN.
ELECTRONICS OF THIS VINTAGE ARE IN NO SHAPE TO BE POWERED UP AT FULL VOLTAGE. SOMETIMES THE SOFT START CAN REFORM THE ELECTROLYTICS. DON'T COUNT ON THAT. THE ONLY TIME THAT I HAD THE SOFT START REFORM THE LYTICS, THE CAPS WERE ALREADY GOOD.
THIS STEP IS BORING AND TEDIOUS. IT IS NECESSARY UNLESS YOU WANT A STATIC DISPLAY. I HAVE ABORTED SOFT STARTS MOSTLY DUE TO CANS GETTING HOT. YOU MUST SOFT START BEFORE AND AFTER RECAPPING.