Sanyo VTC 9455 Betamax - No colour

[dj_fivos_sak]

So, I left the VCR turned on for an hour and tuned to a channel and I finally managed to get colour out of this thing but only from the tuner! I can select between PAL and SECAM and the LEDs light up but it's still black and white when playing tapes. To me, this definitely seems like a capacitor(s) issue. What do you think?

[Philips210]

Originally Posted by dj_fivos_sak

My VTC 9350 says "IC electronics" on the logo

Hi.

I am just trying to envisage what the size of the VCR would be if it were to proclaim "Discrete Electronics", probably something like the size of a gas cooker!

Regards
Symon.

[dj_fivos_sak]

Well, here it is. It's just a 9300 for the Middle Eastern market.

Fivos

[dj_fivos_sak]

Good news. I changed a couple of caps (4.7uF and 10uF) on the chroma board and after a little adjustment of the pot, I got colour working fine on PAL (1st attachment) and SECAM (2nd attachment). But when playing an NTSC tape (3rd attachment), I get that weird rainbow effect on the picture. The tape that I played is a pre-recorded movie on Beta hi-fi. I read somewhere that Sony reduced the chroma bandwitdth in order for the hi-fi audio tracks to fit on the tape, and that causes incompatibility when playing Beta hi-fi tapes on regular Beta machines. Can you confirm that?

Regards,
Fivos

[dj_fivos_sak]

Originally Posted by dragonser

I would assume ( a dangerous thing ! ) that there might be different crystals for the different Tv standards. these frequencies should be able to be found out, and then there could be some crystals ( small metal cases ) with the frequency on them.
It might be worth noting the part numbers on the ic's and see if doing a search on them gives any info on their function.

Hi. I took a look on the ICs and with a help from a Sanyo manual, I found what the ICs do. The manual doesn't mention the 9455 but its Sony ICs are common with many more models. Can you tell me what a sync separator does and why does the 9455 have two of them? Sorry for being a newbie.

Fivos

[Ryan_1993]

I have a VTC 5000 that was showing black and white only, it also had an extremely jumpy picture. For less than a split second I maybe got 1 colour frame. I was told the video heads had practically had it and on examination the head was extremely warn out with loads of white spots on it. The audio was good though that was about it, but thats a separate head so makes sense.

[dj_fivos_sak]

I have a working VTC 5000 but it just needs a clock/timer PCB because mine is cracked. Since the 5000 is PAL-only, I guess it's not that hard to solve colour problems. The 9455 however is multi system which makes it harder to solve those issues. It's playing in colour now, but it records in B/W. I think I have to pop the power supply open and look for some bad caps, as it uses a switching PSU like the Sony SL-C7.

[dj_fivos_sak]

Just a little update on the problem. I made a recording with the VTC 9455 today and then played it back on my working VTC 5000. As you can see, there is some sort of colour recorded but it's very weak and noisy and the picture switches from colour to B/W all the time. Any ideas? Is there any chroma recoding current I need to adjust?