I got a machine like this today, a heavy tank from around 1975, some of the belts and idlers was melted, but is fixed now, when i play a tape the pictures is fine, but no colour, does anyone have experience about VTR´s with colourfaults? i can't find a service manual for this machine 🙁
Alex
That's an interesting find. What market is it for, PAL, NTSC or SECAM and do you have some known good pre-recorded tapes? Colour faults on VCRs can be evil and very difficult to fault find, also I know nothing about this format other than some passing similarities to Beta with the tape transport. With some JVC VHS machines no colour could be traced to leaky colour/B&W switches at the rear. Good luck with the hunt for a circuit, I think you will definitely need it to progress. It also helps to have another machine to see if it's recording colour correctly or if it's a playback path fault.
when i play a tape the pictures is fine, but no colour
You don't say if you have just a single tape which exhibits the no colour symptom, or it occurs with multiple tapes. If you have just a single tape surely you cannot be certain it is the machine.
Assuming you have more than one tape, and the fault is present on all when using these other recordings, have you tried following the instruction of the user manual?
On page 7 it states if the colour playback picture is monochrome, the colour varies erratically or presents colour stripes, then you need to turn the "Colour Lock" control to manual. Then turn it slowly and stop when the picture is normal. Have you spotted that control, have you tried that?
It's probably a long shot but worth a try.
Haven't been able to find the user guide but Radiomuseum states it's a PAL machine, the E for Europe in the model number should have been a clue for me. Also there is a colour switch at the rear.
That's an interesting find. What market is it for, PAL, NTSC or SECAM and do you have some known good pre-recorded tapes? Colour faults on VCRs can be evil and very difficult to fault find, also I know nothing about this format other than some passing similarities to Beta with the tape transport. With some JVC VHS machines no colour could be traced to leaky colour/B&W switches at the rear. Good luck with the hunt for a circuit, I think you will definitely need it to progress. It also helps to have another machine to see if it's recording colour correctly or if it's a playback path fault.
Hi John, it´s for the European market, and yes i have some god tapes recorded on other machines so i know they are fine :-), i will make a try what you sugeest, maybe there is a bad connection in the colour potentiometre
May be worth checking the other tapes aren't Hi Band recordings, they will playback in monochrome. I've never worked on the electronics of U-Matics, but the format does suffer with flashing or an unlocked colour effect on saturated reds
There also appears to be an SP, Superior Performance version of the format which makes it a bit of a minefield.
