PDA

View Full Version : Building a Tandy 1000 RL\RLX power supply



Compgeke
May 14th, 2012, 09:00 PM
I have 2 Tandy 1000s, one with no PSU and one with a broken one (cracked PCB from someone pressing the switch too hard), and I'm willing to build one myself using whatever it takes (neither have a top cover, one doesn't have a floppy drive, so who cares what size a PSU is).

From what I can tell the power supply outputs +5v, +12v and -12v. The connector to the motherboard appears to be (from red to white), +5v, +5v, G, G, +12v and I'm not sure what the white is, I'm going to assume -12v as that's the only one I can't identify for sure (got the other connectors from the pinout of the molex connector that runs through the 4 center pins).

From what I can tell a PSU can easily be built from a regular AT style power supply, or possibly a power brick from an external CD drive if I could find one with -12v, I'm holding one now that outputs everything except the -12v, heck, even an older ATX power supply can probably be modified to work as a toggle switch connecting the power on (green) to a ground would work and fit into the original power switch hole.

I'm looking to find out if my observation pinout for the PSU is correct, and if it's possible to hack together something else to work with this.

Thanks!

k2x4b524[
May 14th, 2012, 10:10 PM
If you would have said something about 2 weeks ago, i had an RSX that crapped out, but the power supply was still good. I have a spare RLX shell. I'll check tomorrow to see if it's got the power supply. If not i may be able to find one cheap for you.

Chuck(G)
May 14th, 2012, 10:40 PM
+5 +/-12 bare switcher supplies are pretty easy to find on the surplus market. Jameco has a bunch (http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDrillDownView?langId=-1&storeId=10001&catalogId=10001&categoryName=cat_4540&subCategoryName=Power%20Supplies%20%26%20Wall%20Ad apters%20%2F%20AC-to-DC%20Switching%20%2F%20Open%20Frame&category=454030&refine=1&position=1&history=lx2ean14%7CsubCategoryName~Power%2BSupplie s%2B%2526%2BWall%2BAdapters%5Ecategory~45%5Ecatego ryName~category_root%5EprodPage~15%5Epage~SEARCH%2 52BNAV%404vuayb11%7Ccategory~4540%5EcategoryName~c at_45%5Eposition~1%5Erefine~1%5EsubCategoryName~Po wer%2BSupplies%2B%2526%2BWall%2BAdapters%2B%252F%2 BAC-to-DC%2BSwitching%5EprodPage~15%5Epage~SEARCH%252BNAV ).

Compgeke
May 14th, 2012, 11:18 PM
That one there would probably work great, and can surprisingly supply more power than the stock PSU can (stock is 25w I believe). As for the fact that I don't have the top cover I think it would be fairly interesting to mount the RLX motherboard in a cigar box and have a small 286 box :P.

I do know of one (somewhat) local store that *might* have one, I'll have to call 'em up tomorrow and ask.

Great Hierophant
August 28th, 2012, 07:57 PM
The RL and RLX have a plus in that they have a no-fan power supply. They original power supplies were rated for 25W, so this one should be right on the money: http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_230536_-1 All the big box Tandys (SX, TX, TL, TL/2, TL/3, SL, SL/2) except for the original 1000s use a 65W supply, so this should be close enough :
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_216734_-1

Would these units from Jameco require the fan if fitted inside these Tandys?

patscc
August 28th, 2012, 08:08 PM
How badly cracked is the PCB ? Is it beyond patching ?
patscc

Chuck(G)
August 28th, 2012, 08:21 PM
The RL and RLX have a plus in that they have a no-fan power supply. They original power supplies were rated for 25W, so this one should be right on the money: http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_230536_-1 All the big box Tandys (SX, TX, TL, TL/2, TL/3, SL, SL/2) except for the original 1000s use a 65W supply, so this should be close enough :
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_216734_-1

Would these units from Jameco require the fan if fitted inside these Tandys?

I'm a little skittish on the first PSU, but the second looks perfect. Is the PSU enclosure ventilated? If so, that should do just fine.