Woo hoo - Collection Completed!! TRS-80 inbound

[exxos]

Woo hoo, it's Zener day!!
Reassembly is imminent

[stephen_usher]

[rubber_jonnie]

All reassembled now

Seen here sat on top of its younger welsh cousin

PXL_20220915_120048777.jpg (261.8 KiB) Viewed 1439 times

Going to leave it running for a while, see how warm it gets.

[rubber_jonnie]

Boy it's a toasty little TRS!!

I think a future project will be to rework the power now that I don't need 12V for the RAM and make it a cooler running machine overall.

[Tomswork]

You may want to re paste the t03 package transistor tandy was cheap on thermal paste and clean the nut and screw on the ground side. I'm not sure if the 12v line is used on the expansion card edge


Tom

[rubber_jonnie]

Well the TRS seems to have reached a point where it's thermally stable. It's still toasty, but liveable with for now. It's been running all afternoon now and seems pretty happy.

I have to say, from my brief experience with the keyboard (An ALPS model) it is really very nice indeed and makes the Dragon one seem pretty poor in comparison. I just remembered too, I had to move the row of in headers from the bottom of the mainboard to the top, or the mainboard wouldn't sit properly with the new IDE cable I used for the keyboard. On top though, it's fine.

I also found a MOD to upgrade to 64KB internally, so I will have a look at that and see if it's feasible to do since I do have larger RAM chips in there already.

[rubber_jonnie]

You may want to re paste the t03 package transistor tandy was cheap on thermal paste and clean the nut and screw on the ground side. Im not sure if the 12v line is used on the expansion card edge


Tom

Yep, I'm considering that, as well as repainting the heat sink. It's not black anymore and I don't expect that is helping.

I suppose I could fit a fan underneath it, there is loads of room and I have 12v going spare now

[stephen_usher]

I don't think that you should be too worried about the nut and bolt making contact as the transistor is getting hot. As Adrian Black discovered, if the bolt isn't making contact then the transistor doesn't work and all the current is supplied by the control transistor, which gets extremely hot and other things start going wrong as it can't supply enough current.

[rubber_jonnie]

I don't think that you should be too worried about the nut and bolt making contact as the transistor is getting hot. As Adrian Black discovered, if the bolt isn't making contact then the transistor doesn't work and all the current is supplied by the control transistor, which gets extremely hot and other things start going wrong as it can't supply enough current.

I'm not worried about contact for the transistor as the screws are soldered in on mine, more about improvement of the thermals.

[Tomswork]

You can always put a pi heat sink on the transistor if your have thermal plaster


Tom