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Author Topic: Broken 12V (Read 158 times)

Offline dangerman

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Broken 12V
« on: 2019.March.17. 18:41:19 »
Last weekend, I started having problems with my Enterprise 64 and I realised there were problems with the 12V circuit. Thanks to previous posts on Enterprise Forever, I discovered the most common fault is with TR2 and C9. So I replaced them both and it started working again. I thought this had fixed the problem.

However, yesterday I plugged in the Enterprise and disaster happened! Smoke came from the case and TR2 was completely melted, and the wire to coil L1 had broken as well. :cry:

Thankfully the rest of the computer seems to work if I wire in an external 12V source... so it's only the 12v circuit that's blown. That is a big relief!

Anyway, I replaced TR2 and C9 again and patched the wire to coil L1, but when I tried power it up - more smoke started coming from TR2, so I unplugged it quick. I think TR2 must be short circuited somehow. Looking at the schematics and using my very limited grasp on electronics, I guess the culprits are going to be C10, TR3 or the coil L1. Does anyone know how I might narrow this down? I have a multimeter but don't have access to an oscilloscope. Is it even possible to get a replacement coil???

All help gratefully received. :(

Online pear

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Re: Broken 12V
« Reply #1 on: 2019.March.17. 20:00:54 »
The coil can be wound yourself.
I wrote about it here.

Offline dangerman

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Re: Broken 12V
« Reply #2 on: 2019.March.17. 22:20:38 »
Thanks for the tip, Pear. I'll get some 0.25mm enamel wire and give it a go myself.

Is there any way to confirm whether it is the coil that is causing the problem? Could it be another component that is causing the short?

Offline Zozosoft

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Re: Broken 12V
« Reply #3 on: 2019.March.17. 22:56:42 »
The best solution buy EPower from Pear, and replace completly the old power circuit. But I don't know he currently have it in stock :oops:

Anyway after I bulit in EPower to many machines, I have spare coils.

Offline dangerman

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Re: Broken 12V
« Reply #4 on: 2019.March.23. 12:15:36 »
Good idea about EPower, although I think I don't really want to replace everything. The 5V is working fine.

Do you need your spare coils, or would you be able to send me one? It would be great if I could fix it.