Hi, I had this exact issue before.
First, this is normal operation if the mirrors are not working properly. The virtual boy has a detect signal to check if the oscillation for the mirror induction motor is operating properly. If it isn’t, the system will not boot an image. I imagine this was done to prevent headaches and health issues.
First thing you want to do is swap the left and right side on the motor controller board. That way you can see if the problem is the mirror / motor assembly on one side, or the motor controller itself that is the issue.
If it’s the motor controller, obviously you can replace that. Or you can double check the green wiring which has a pretty janky connector that can give issues.
If the issue moves when you swap connectors, then you know it’s your mirror assembly. Move on to the next step:
There is a photo interrupter/optical coupler that a plastic bit in the mirror slides through many times a second to produce a successful signal. Make sure that that piece is thoroughly cleaned with alcohol and doesn’t have any debris in it, as that can cause this issue since it blocks the optics from communicate with each other. You can also try replacing it, I’ve attached an image to show you what they look like.
Failing that, I would try slightly bending the green cable from the motor controller board to see if that has any effect. Beyond that, you might have to replace the mirror motor assembly as I don’t know the way those can be repaired since they are highly calibrated. You can order yourself a Virtual Tap and turn it into a home console as well…
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I greatly appreciate you both responding! I did try to do some searching on the forums and other places but my search terms must have been lacking.
I’ll definitely give those things a shot and the extra picture is a huge help.
*I swapped the motor connections on the servo board and the issue followed the servo board connection. So seems the issue is on the board. It would be great if a recap would fix it haha
I just got one like this in my shop today. This one is the right side. I’ve fixed a bunch of bad ribbons, and a couple power supplies… but never a servo driver. I’ll be tinkering with it. I’ll post up if I figure it out.
So far… I’ve had the mirror settle down… but you will see the screen blink. Then… it will over oscillate. (To the point of hitting it’s stop)
Just wanted to do a follow up on this….
I just got the one in my shop running correctly. BUT… there wasn’t a single “There it is” kind of problem. I think it’s a combination of several things. I first looked at the photo gates. They were clean, and working correctly using normal test methods for an LED and phototransistor. But, I gave them a physical cleaning. Next I checked the Xtl on the servo board. It seemed ok, but I was reading a higher overtone. (but confirmed on a working VB) I took apart, and cleaned all the connections, (including the little ground clips) and I resealed the ribbons for the LED arrays. (My typical LED repair) I then reflowed all the connections on the servo board, (looking for a cold joint) and replaced the capacitors. One of the caps MAY HAVE BEEN out of range… but they were not “Dead” by any means. (only slightly higher resistance over the new ones)
Oh… and did some other basics like verified power stability. And when I said “Cleaned the connections”… I used IPA and a cotton swab to make sure they were electrical clean.
At this point… it was better, but it would still blink and image, and over scan… and then settle back.
From there… I looked at the 2 pin connectors on each of the Galvo’s. I thought maybe they had some corrosion behind them… so I wetted them with IPA, and gave them a little twist back and forth. I also decided to replace the caps on the main board since there was only 4.
At each step… when I would check… it would seem slightly better. After I finished giving it a full service… (caps, cleaning, reseating) it seems like it’s working. I’ve had it powered on for 35 min or so, and I haven’t heard the mirrors “Rattle” because of being overdriven. And every time I look in… the picture is stable. If it stays good for another 30 min… I will call it done, and send it back to the customer.
I don’t like when it’s not a clean, “smoking gun” kind of fix… but lets face it… it’s a strange system, and a bunch of small issues could combine and lead to the overdriving, and unstable servo.
Hope that helps.
