View Full Version : URGENT HELP TRS-80 III

5th March 2005, 07:36 AM
OK after about 4 months in storage i took out my Trs-80 III and when i turn it on i get nothing.
after i opened it i found some stickey substance on the monitor it looked like it was coing from you know that big round thing that connects to the Monitor, the thing is that it's all over the monitor it's not just in one place!

Thankyou so much! :(

5th March 2005, 07:46 AM
Sounds like a capacitor blew its load inside your TRS-80! The sicky substance is electrolyte from inside of the (big round) capacitor. You could try cleaning it up with isopropyl alcohol and replacing the capacitor with one of equal value, but it's a fiddly job. Otherwise it's dead. Sorry. RIP. :(

EDIT: P.S. A CRT stores a lot of charge at dangerously high voltages - even when it is turned off. You really shouldn't touch anything unless you discharge the CRT first.

5th March 2005, 07:52 AM
Where can i get isopropy!

5th March 2005, 07:55 AM
Or can i clean it up wih alc (alcohol) 51%

5th March 2005, 08:12 AM
Isopropyl is the alcohol used in head cleaning fluid. You should be able to get it at Dick Smith or some other electronics store. You could also go and get some pre-injection swabs from the chemist. I personally find these convenient to use for fiddly jobs.

It is important that you realise before you start that the offending capacitor will need to be de-soldered and removed, and a new one re-soldered in its place.

You will find the capacitor rating written on the side of it. It is important to get ALL the details, including capacitance (usually in F), voltage rating (V) and polarity (which end is positive - very important). If you put a capacitor on the wrong way it can EXPLODE. Not scared yet? read on.

You should discharge a CRT before working on it because of the high voltages they contain, even when switched off. If you can't discharge it, you should wait a while after switching it off (24 hours at least) and even then don't touch anything unless you absolutely have to.

If you're smart you'll quit now. Otherwise, good luck!

5th March 2005, 08:22 AM
So what should i do with the computer just throw it away?

5th March 2005, 08:27 AM
Depends how much you love it.

5th March 2005, 08:33 AM
i love it alot but i would love it more if it worked maybe it might turn on next time!
But i remember before when it worked the screen used to move alot and then after a while it would stop!
another thing is that i have no equipment to do the job! :(

5th March 2005, 08:39 AM
I don't think it will turn on again without surgery. I think you should accept its passing and send it on into the hereafter.

5th March 2005, 08:42 AM
But if i turn it on will it blow up?

5th March 2005, 04:51 PM
Originally posted by applecollector@Mar 5 2005, 08:42 AM
But if i turn it on will it blow up?
If you've blown a cap, chances are there'll be no voltage through the circuit that it is a part of. Generally the fist caps to blow are your main voltage filters, which smooth voltage to the rest of the unit. Powering it up now will probably do nothing, but I wouldn't bet my lunch money on it.

As mentioned, you need to be ultra-careful inside and around CRTs. These things can store up to 30,000 volts even after being powered down for some time. If you're not careful and zap yourself, best case scenario: you get thrown across the room. Worste case: you die.

I'd advise taking the unit to a qualified TV repair person, and showing them the fault. Ask them for a quote on replacing the main capacitor, and cleaning up the muck from the leaked one. They'll have the tools to safely discharge your CRT and do the electrical work needed.

Alternatively, sell the unit on Ebay as non-working to some collector, and get yourself a TRS80-III emulator instead.

Even better: here's a guy who wrote one to work in Java on your browser:


5th March 2005, 05:12 PM
Originally posted by applecollector@Mar 5 2005, 07:36 AM
i took out my Trs-80 III and when i turn it on i get nothing.

Whats so urgent?

Are you needing it to run some SETI@Home units or something?

If worse comes to worse. You can pick these up on ebay for a few dollars. Cheaper than getting it repaired I think