Vintage Radio Shack Tandy TRS - 80 Model 4 IV Power Supply, Tandy, 8790049

Working Vintage Radio Shack Tandy TRS-80 Model 4 IV Power Supply, Tandy, part #8790049. This power supply is in used but working condition. I removed it from my own Model IV to replace it with a modern switching supply with a higher wattage rating because of (an initially) suspected voltage sag issue with this supply. The symptoms with this vintage supply were that while booting from floppy disk the display on the CRT would shrink some, but then recover. However, I later found that it ...was one of my two floppy drives which was placing the inordinate load on the power supply.
This supply always worked fine in this 64k Model 4 in tape mode, very reliably. And the voltage rail for the RS232 port works too. It was only with the extra load of the drives where I was dissatisfied. But again, this appears to have been due to a fault in one of my drives. However, I did not ever put this vintage supply back in the computer to see if that issue was resolved.
Guaranteed to work for you as described here or your money back, no questions asked. Buyer pays return shipping, of course.
This vintage supply will be carefully packed and shipped in a sturdy box. Shipped USPS Priority Mail.

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