burning TRS-80?

[Computer Collector]

Ive had my TRS-80 model 4 for many years now. (its the picture in my avatar). Well, last night something really weird happened. I was using BASIC and then decded to step out of the room and get a snack. After eating, when I came back, the room smelt like it was on fire! I got worried and was looking everywhere but did not see and flames or smoke. But it smelt like the dang house was burning down! I realized that it must be the computer so I quickly shut it down. I opened the windows and after a few minutes, decided to use the computer again and check it out. Again, there was no smoke and no flame, but it smelt like there was a fire. I looked into the top of the computer and saw nothing in there except for the back of the tube lit up, which is normal, I believe. The computer worked just fine, though. I finished what I was doing, printed it out on my DMP printer, and that was that.

Did this ever happen to anyone else? What on earth could have been burning?

[chuckcmagee]

All kinds of things can be burning. Capacitors, transistors, voltage regulators immediately come to mind.

[atari2600a]

Take a screwdriver to it & look. Just remember, the CRT is attached to the top, so when lifting the top tthe case up, it will be heavy & there will be a couple wires attached to it.

If it dies & the mobo is still good (& you don't plan on fixing it), can I have your mobo? Mine's not working...

http://mtac.profusehost.net/trs804/trs804.jpg

[carlsson]

What kind of video circuitry does those TRS-80 have? Something akin of a Motorola 6845 chip, but perhaps Zilog/Intel, or more low-level method to generate the video? One of the PETs I picked up didn't sync, and I got some advice what to measure without any luck. A while later, I picked up a spare MOS 6545 chip and replaced the old one, and got it to work. Unfortunately it has gone completely silent/dead over summer. Maybe it is a simple error but I didn't have time to investigate it yet.

[Terry Yager]

I've had transformers behave in a similar manner, bad smell with no visible spitzensparken or majikal smoke. The difference is, they don't seem to work afterwards. Lemme know if you need any parts, I may have some (untested at this point).

--T

[curtis]

Wasn't there a string here somewhere a while back about the HCF command?

You know, halt and catch fire? :onfire:

Curtis

[atari2600a]

This doesn't look like a HCF poke, as that would kill the circuitry within seconds & there'd be smoke.

[alexkerhead]

Check the power suply board, sounds like a transistor going bad. If it is bad, it could be letting a large amount of bad current into the board, so check for burnt looking transistors.
Transistors are not aweful to replace, but you will need some soldering finess.


Atari, seriously, it is rude to ask for parts from someone when they haven't offered any.