Zenith VRF-255 VCR Repair

Problem:The video picture was incredibly distorted when playing tapes. There were multiple wavy lines going across the picture that made this VCR unwatchable.

Troubleshooting: The first most obvious solution would be to adjust the tracking. This VCR has manual tracking. Adjusting the tracking on the VCR made no difference, and at times, even made the picture way worse. I then assumed that the video heads on the video drum were dirty. Dirty video heads is one of the most common problems that will result in a messy picture that tracking won't fix. I opened up the VCR and using alcohol and a paper towel, I gently cleaned the video heads on the video drum. Once again, there was no change in the picture and the video distortion continued.

At this point, I decided to research because I wasn't sure where to proceed. I learned that the tape roller guides are adjustable. The tape roller guides adjust how the tape lays against the video heads on the drum. If the tape guides are misaligned, the tape will be misaligned against the video heads, thus, resulting in a bad or distorted picture. The left tape roller guide is responsible for the top half of the picture, and the right tape roller guide is responsible for the bottom half of the picture. As you adjust the tape roller guides, the picture will adjust on your TV. Ideally it's best to do this as the VCR is running so you can see what changes are taking place. Be sure to have common sense when messing with live circuitry.

These are the tape guide rollers. You adjust the metal tops to adjust the picture. Some people adjust with a flathead screwdriver or another type of specialized device. I just used my fingers to adjust the tops by turning the metal part left or right.

Eventually after much adjusting, I was able to get the picture looking normal by adjusting the tape roller guides. However, a staticy white line appeared at the bottom of the picture no matter what adjustments I made. It was clear that the tape still wasn't completely properly against the video heads. Also, anytime I ejected the tape and played it again, the distortion came back and the guides needed to be adjusted again. Sealing the tape roller guide's tops in place with a light adhesive (such as nail polish) might help them stay in place, however, I assumed my issue wouldn't be resolved by doing this, as the white line at the bottom of the picture meant there was more than just guide adjustment that needed to be addressed.

The static white line at the bottom of the picture persists

Solution: Missing tape guide roller post on the VCR.

After looking at the VCR closer, I realized that one of the tape guide roller posts were missing. Specifically, the left tape guide roller post. These go right next to the tape roller guides, and the tape roller guide posts help bring the tape itself closer to the video heads. Without a tape roller guide post, the tape will not ride against the video heads much, and thus, you will have a very distorted picture.

The left post (pointed to in red) is missing, while the right post (pointed to in green) is correctly in place. You can see that without the left post, the tape has too much slack and is not against the video heads correctly. For comparison, look at the right guide post and see how snug the tape is against the video drum.

To test if adding a tape guide roller post would solve the issue, I got a small plastic tube (from a can of electronics spray) and placed it where the tape roller guide post would be. I slowly maneuvered the position of my "guide post" until the picture on the TV looked perfect. This was the issue all along.

However, a plastic tube wasn't ideal as a replacement part, as tape guide posts are made of metal. Unfortunately, finding such specific parts for a VCR is near impossible. To find a replacement part for my tape guide roller post, I measured the length and diameter of the other existing tape guide roller post. Use millimeters for your measurment, as this is much more accurate than using inches, since we're dealing with very small pieces. Then, I re-measured these measurments over where the tape guide roller post should be, just to make sure that measurment seemed right for the other post. In doing this, I discovered that adding a few extra millimeters for the length of the left post would be better. With my measurments, I ordered a pack of "metal dowels" in the millimeters I needed. Simply look up your measurments with "metal dowels" in your search, for example, "15mm 4mm metal dowels" (15mm being the length and 4mm being the width).

This is the metal dowel I'm using as the tape roller guide replacement part.

To secure the metal dowel into the hole where the tape guide roller post is supposed to go, you will need a strong adhesive. At first I tried to use a quick setting epoxy, however, I found epoxy to still take too long to set. It's incredibly important to place your tape roller guide in the VCR while the tape is playing, because you need to see how the position of the new post will change the picture. You can't just glue in a tape guide roller post and hope it will work. It's important to apply glue to the hole where the post will go, then engage the tape, then place the dowel in the hole and make adjustments for the dowel's position as the tape is playing to ensure the post aligns correctly for a good picture. While epoxy "sets" in 5 minutes, the epoxy is still gummy and maluable. This means even if you hold the tape guide roller post in position with your hands for those 5 minutes, the second you let go, the pressure from the tape running against the post will adjust the post, and now, your post will set in an incorrect position because the post is not being held in place nor drying in the correct position. This is why I ultimately decided that epoxy wasn't going to work for me.

I removed the epoxy (it was still gummy) and instead applied super glue to the hole. Then I engaged the tape, and I quickly applied the metal dowel into the hole where the guide roller is supposed to go. It's important to do this as quickly and as accurately as possible, because you need the post to be in the correct position while drying in the correct position. Be sure to not add too much super glue, as this will create a similar "gummy" non-drying problem that the epoxy has. Use just enough to secure the post in place. Once the post is in place, hold it there for a few minutes. I held the post in place for 10 minutes to ensure it was drying at the correct angle. If you let go too soon and the post is not fully hardened/dried in place, the pressure from the tape against the post will adjust the post and thus, misalign the post, resulting in a permanent bad picture (unless you remove the post and try again). After 10 minutes, I let go of the post and it was holding the position correctly. I then ejected and removed the tape and let the post sit in place for a few hours, as I didn't want additional pressure to adjust the post as it was freshly dried. I also applied super glue along the edge where the post and the VCR mechanism meet, to ensure that the pieces will stay binded together. I also applied hot glue in a similar fashion around the edges where they bind. You could do expoxy in this area instead of super/hot glue for a tighter bond.

The new left tape roller guide is in place.

After a few hours, I powered on my VCR and put in a tape. The picture was now completely perfect and I had succesfully replaced the tape guide roller post.

In conclusion: The actual process of replacing the guide post was very difficult, because you have to work very quicky and very, very carefully. You do NOT want to risk getting expoxy or super glue on the video heads, and this is a very real risk since the tape guide roller posts are right next to the video drum. You also don't want to drop the guide post into the VCR, because then you risk shorting components together or worse, a post smashing into the video heads and ruining the video heads. You also have to work quickly and very accurately so your post doesn't dry in an incorrect position and then you're dealing with a semi-permanent incorrect picture. While this repair wasn't conceptionally difficult, it was tedious. I'm glad I was able to figure out what was going wrong, as not too long ago, I might have not been able to figure out the issue and wouldn't have a working VCR.

You can contact me if you are having trouble with your VCR. I am not an expert and only do this as a hobby, but I may be able to provide guidance.
Phone: 725-286-3278
Email: ashleyjones@icum.to

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