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smoking hp85 - Andy - 02-10-2003

When I powered up my hp85 this weekend, the following happened:

1. The tape light came on
2. A burning smell eminated from the back

So I took the cover off and tried again. There are a couple of transformers near the CRT. One of them was smoking.

Any advice?



Re: smoking hp85 - Mike Meyer - 02-10-2003

Have you tried laying an HP-10BII across it?

Sorry. Couldn't resist.

Re: smoking hp85 - Andy - 02-11-2003

:) I don't have a 10iib but if i did...

On a more serious note, I discovered that a capacitor downstream of the transformer had gone bad (it reads shorted).

Hopefully the transformer is still good (even though it was smoking, it still reads good) and replacing the capacitor will get it working.


Re: smoking hp85 - Michael Meyer - 02-11-2003

Nice find. There are many here who know more about electronics than I.... but I agree. If the voltages look right, the transformer should be OK. I wouldn't power it up and then go out to dinner, though...


Re: smoking hp85 - Andy - 02-11-2003

I replaced the bad capapcitor and re-installed the transformer. I accidentally put the transformer in backwards. Belive it or not, it only blew the main fuse.

After properly re-installing the (still good) transformer, my hp85 is up and running again!! :^)

Now onto replacing the little gummy wheel so I can get the cassette drive working too.