Video time base corrector self destructing mains socket

Filtered mains socket self destructs in CEL TBC

We have several time base correctors and frame synchronisers at our disposal. One recent addition is a new old stock (NOS) CEL Tetra. This is an early 1990’s motion adaptive Standards Converter for PAL, SECAM, NTSC 3.58 and NTSC 4.43 systems. A very flexible unit with composite, Y/C (S-Video), umatic DUB High Band/Low Band and component inputs and outputs.

Out unit still has it’s shipping caps over the BNC sockets and looks unused but after 5 minutes of power a cloud of white smoke billowed out of the cooling fan accompanied by a pungent smell. The Shaffner EMI mains filter had a nasty, sticky brown residue leaky out and all around the back of it. This is the second TBC that I’ve had this happen to. I’d assumed these units get left on for long periods when used in broadcast applications which would hasten their demise. According to their website, the mean time between failures (MTBF) of their recent products is around 2,000,000 hours! Our CEL TBC doesn’t look like it’s done more than 30 minutes so maybe there’s been some dodgy electrolytic fluid in these units just like the motherboard capacitor problems between 2000 and 2003.

1 comment

Sounds like the standard fault with the Antec power supply used in BBC Micros — the plastic dielectric in the X2 mains filtering capacitors goes brittle and cracks after 20 years or so. Plug in a BBC that’s been turned off for a few years, and there’s a good chance that after it’s had a few minutes to warm up, at least one of the capacitors shorts briefly and explodes in a cloud of white smoke. (And, if you’re unlucky, little bits of foil all over the power supply. Mutter. At least it’s easy to fix, and does no harm to the rest of the machine.)

Leave a Reply