capacitors

V2000 bad Frako capacitor in Grundig 2×4 Video 2000

Video 2000 Frako X2 capacitor in Grundig 2x4

Yet again bad capacitors have reared their electrolytic fluid! This time in a Grundig Video 2000 video tape player, or V2000.

Pictured above is a X2 mains film cap in the power supply of the video machine, made by Frako. This brand of capacitors are German and used in many Studer audio tape machines too which commonly have similar smoking fun such as the B67 and sometimes the A80.

A nice satisfying repair though – all Frako film and electrolytic capacitors were desoldered and replaced with 105 degrees rated Panasonics. The circuit boards on these type of machines are also well made with thick tracks so there’s little risk of lifting solder pads with this type of repair.

Other than their ageing capacitors and some dry solder joint problems these Grundig machines are excellent although as with many older domestic formats the important proprietory spares like the V2000 upper head drums are very rare new now so keeping these machines running will get harder and more expensive over time.

It’s a good idea to digitise and transfer any video recordings on formats like Video 2000 to file based digital formats or at the very least DVD sooner rather than later.

Posted by greatbear in video tape, video technology, machines, equipment, 0 comments

Sony PCM 7030 DAT repair

Sony PCM 7030 DAT machine

We have several of these large, wonderful machines. It’s not often we need or want to get involved in DAT machine repair as generally they are not easy to service machines and many key transport parts are becoming unavailable. The Sony 7030 DAT though has been designed with easy servicing in mind. There’s alot of room in these things and each section is clearly marked and separated into distinct boards much like Sony Broadcast video machines.

These are timecode DAT machines and were once common in video post production houses and the more well funded recording studios. The problem with some of this well built kit though is exactly that it works too well and gets left on for long periods through it’s life and this can take a toll on certain components, especially electrolytic capacitors. Heat builds up in electronic circuits, especially in switch mode power supplies that larger broadcast items often use. Capacitors have a rated life at 85°C or 105°C at several thousand hours. With hotter environments, substandard parts and long operating hours these capacitors can soon outlive their original design life.

Our 7030 DAT had started behaving oddly and at first the display would flash on and off after a short while powered on. Another machine would power up for 30 secs then just die. Before delving into the enormous service volumes it’s always worth replacing the Switch Mode Power Supplies (SMPS). These like many broadcast machines use supplies that are sometimes generic made by other companies and which can be bought at Farnell or RS. We did it the harder way and desoldered all the old capacitors in the power supply and replaced these with high quality low ESR Panasonic ones which should give us another 6000 hours of running time. So far this machine has worked perfectly although you do need good soldering and desoldering technique on these boards. A powered air desoldering station is a good idea, much, much better than a hand solder pump.

Posted by greatbear in audio tape, audio technology, machines, equipment, 4 comments

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 1990s 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), U-matic DUB High Band/Low Band and component inputs and outputs.

Out unit still has its 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 leaking 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.

Posted by greatbear in video tape, video technology, machines, equipment, 1 comment