Originally Posted by
Calamity Jane
I am just about finished restoring 3 Dichro 45s - only have a metering problem left in one unit. One unit had the exact same problem.
The most common (and universal) problem with the Dichro 45 is corrosion of the board-edge connectors and headers. At the time when these units were made, connector technology had some bugs.
The proper fix is to clean all the connectors, which means removing the 3 circuit boards. (Mark all the cables to the power control board with the P number on the board so you get them back in the right places!) The male header pins on the motherboard will show black deposits on the side toward the daughterboards. This needs to be cleaned off with some VERY fine emery cloth or sandpaper - "contact cleaners" will NOT remove these deposits. For all of the female headers on the daughterboards, use acetone and small wooden toothpicks to scrub every single one of these puppies! Keep working the toothpick back and forth into the connector hole (across the contact spring). When it gets dirty, switch to a clean toothpick and keep going until 4 or 5 strokes leaves the toothpick coming out clean, then move to the next one. I did one Monday and it took 3 hours :-(
When all the connectors are clean, put it back together.
I'd wager $100 your problem will have disappeared!
I'd suggest you could take it to a TV/radio repairman if you don't feel confident doing this yourself but 90% or repairmen will not take the time to do it right - they will spray it and call it good.
You may be able to get away with unplugging and plugging in the control board and the processor board (these are the only two that effect the lamp) and that saves disconnecting the miriad of cables from the control board.
WHAT AM I DOING????!!!! If I give away all my secrets, I won't get any more cheap 45s 'cause people will be fixing them themselves!!!
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