Tandy 1000 SX Power Supply help

[1984BBS]

Good evening all, I should have create an account here years ago!

I'm a collector of IBM PC 5150s, 5151 Expansion units, IBM XT 5160',
IBM XT 286 5162's, IBM 5170's, IBM 5151, 5153 and 5154 CRTS and accessories for these models.

My first IBM compatible computer was a Tandy 1000 original model (Non-A).
I recently purchased one that is in mint condition and works flawlessly, however the 3 slot limitation really troubled me as once I upgraded to 640K ram and added an xt-ide I was left scratching my head to install a modem, a serial adapter or a network card

So the adventure began again and I purchased a Tandy 1000 SX, it arrived today and I wasted no time ripping the box in shreds in order to start playing, however when turning on the system nothing happened. When flipping the power supply switch back off I could hear some slight wining noise, perhaps from the power supply.

I've completely disassembled the system and inspected the power supply and the motherboard. I can't find anything wrong from a visual inspection on the motherboard and the only thing I can see of possible interest inside the power supply is appears to be some heat on top of the transformer in the center of the power supply, which resembles a small brown mark. All the capacitors have a red mark as someone has already inspected them or replaced them, none appear to be building and nothing leaking anywhere.

Can anyone point me out where I could purchase a replacement power supply for the Tandy 1000 SX until I can get this one fixed? Or if there is someone that can fix this one? If not can anyone share the top 5 common issues with the Tandy 1000 SX power supplies?

Thanks in advance,
Dejavu

 

[keenerb]

Good evening all, I should have create an account here years ago!

I'm a collector of IBM PC 5150s, 5151 Expansion units, IBM XT 5160',
IBM XT 286 5162's, IBM 5170's, IBM 5151, 5153 and 5154 CRTS and accessories for these models.

My first IBM compatible computer was a Tandy 1000 original model (Non-A).
I recently purchased one that is in mint condition and works flawlessly, however the 3 slot limitation really troubled me as once I upgraded to 640K ram and added an xt-ide I was left scratching my head to install a modem, a serial adapter or a network card

So the adventure began again and I purchased a Tandy 1000 SX, it arrived today and I wasted no time ripping the box in shreds in order to start playing, however when turning on the system nothing happened. When flipping the power supply switch back off I could hear some slight wining noise, perhaps from the power supply.

I've completely disassembled the system and inspected the power supply and the motherboard. I can't find anything wrong from a visual inspection on the motherboard and the only thing I can see of possible interest inside the power supply is appears to be some heat on top of the transformer in the center of the power supply, which resembles a small brown mark. All the capacitors have a red mark as someone has already inspected them or replaced them, none appear to be building and nothing leaking anywhere.

Can anyone point me out where I could purchase a replacement power supply for the Tandy 1000 SX until I can get this one fixed? Or if there is someone that can fix this one? If not can anyone share the top 5 common issues with the Tandy 1000 SX power supplies?

Thanks in advance,
Dejavu

I would inspect the motherboard closely. A shorted tantalum capacitor might cause a symptom like this, I believe.

 

[1984BBS]

Thanks for the response keenerb,

I disconnected the power supply from the motherboard and turned on the power supply with no load. The rear 12V fan doesn't spin and when I power it back off I can hear a high pitched frequency that slowly fades out. I assume what I'm hearing is a validator discharge?

Happen to know where I can source a replacement power supply?

Dejavu

 

[Towmater]

I just put a modern PSU inside the Tandy power supply enclosure, giving me the same power switch, but with some extra piece of mind.