Hi I got a cheap CLD-3090 off eBay. I bought a working DVL-700 later, but I thought I would keep this around as a secondary LD player because I thought I could fix it. Long story short, it had a broken gear pulley that I replaced, and all seemed to work fine. It would play both CDs and LDs with no issues. Worked perfectly but was noisy so I have some grease coming.

Today, I removed the clamper assembly again to clean the laser, and put it back on. Then it wouldn't spin up discs. Tried LDs, then CDs, nope. Made sure the clamper springs were secured, they were, everything looked fine but it just wouldn't spin up.

I couldn't figure out what was wrong, so I removed the tray and put it back in. Now it doesn't want to eject probably, I think it's not "detecting" that the tray is fully closed. I'm sure the alignment on the tray is correct. Also the belt was also replaced by me, so it's not a slipping belt.

Then out of nowhere, I saw a flash from the power supply and it went dead. A multimeter and my naked eye was able to tell F101 on the PSU was blown. It was completely black and no continuity.

It's a 125V 2A fuse, but I'm not sure what size or if it's fast-blow or slow-blow. I think it's a 5x20mm slow blow, but the manual says nothing.

What could have caused it to blow? I'm positive nothing metal got into the PSU and I heard no popping sounds, just saw a slight flash.

I cannot help but think, since each time you try another test/repair/improvement attempt, instead the player gets worse. The only thing obviously in common is "things were removed/disconnected and then put back". Unfortunately, that points to things such as connectors that may not be tight, or somehow got mis-aligned, or wires in their cables broke or came loose perhaps.

Since you already know "the best it ever was" is "noisy", I would leave it alone until you get the grease, or maybe just do some very careful inspections with good lighting, but do not attempt to operate or use it until you can at least do the lubrication.

To directly answer the fuse question, slow-blow versus fast-blow is usually noted in service manuals (and would be fast-blow if not marked otherwise). And if the fuse blew after the machine was turned on for a couple of minutes or more, that implies that something was taking too much current, exactly what can happen with electro-mechanical devices needing lubrication, or items that are jammed/crooked.

I wish that I had better news, but the machine needs close examination to find out why it keeps getting worse.

That fuse is only supposed to blow when the power supply is flowing more current than it should. This happens when shorts occur or when motors are too hard to turn. Sometimes “main” fuses will die just from age. If that’s the case then it won’t blow the next one. If it does blow the next one the short is still in place. That would be great, diagnostically speaking, since shorts that stay are way easier to find.

The short can be anything conductive laying across any path anywhere in the player. It could also be failed components. Since you had new issues with discs not spinning up just before the PSU blew a fuse I’d say it’s more likely than not that the issues are related. I’d suspect something was mechanically binding related to the drawer and the work you did in that area. This may have weakened the fuse causing it to blown easily later.

I'm certain the tray is aligned, I've removed and put it back in multiple times and even removed the front panel to check the alignment, but it doesn't seem to be loading in the player all the way. For example, when the tray is closing and it stops moving (when it's inside the machine all the way) the VFD still says "CLOSE" for a few more seconds but the motor isn't running. When I try to eject, the door for the tray won't open and I don't hear the motor running. If I manually open the door and force the tray up it will then come out normally. I don't think I put the tray in wrong but I'll take videos and photos tomorrow when the fuses come.

I just replaced the belt but I might try another belt and see what happens.