TI99/4A QI Console Power Supply Repair

[mvancopp]

Hi,

I have been resurrecting my older TI equipment and I am down to one non-QI motherboard left to repair and two QI console power supplies that are not working. I would like to repair them but I haven't found any schematics to make the job easier. I am capable of tracing these out and making a schematic but I'd rather not reinvent the wheel if their is already a schematic floating around. I have found the non-QI power supply schematics in my places.

 

Does anyone know of a schematic for the QI console power supply?

 

BTW: The motherboard that needs repair is from the first TI I bought back early 83(??? hard to remember but the chip date codes match this). My wife-to-be was vacuuming and hit a connecting wire, the video out I believe. The cord was sucked up and stripped and the console smoked (the pcb trace for sound to the DIN connector vaporized and a number of other failures). I saved my money and bought another console and put that console aside since then, about 39 years.  So their is sentimental value in getting this console running again 🙂 

 

Thanks for taking the time to read this! Any help is appreciated.

Mark

 

[+Ksarul]

I'm pretty sure the schematic for the QI power supply was included in the bag when Radio Shack was selling them as surplus TI parts in 1984/1985. I'm not sure If I have any bagged ones left to check though. . .

[mvancopp]

2 hours ago, Ksarul said:

I'm pretty sure the schematic for the QI power supply was included in the bag when Radio Shack was selling them as surplus TI parts in 1984/1985. I'm not sure If I have any bagged ones left to check though. . .

Thanks for the reply.

 

I didn't get these from RS stock 😞 (one came from a console and the other was bought on Ebay without any supporting docs). I did find the issues and it turned out to be simple. There were two capacitors that failed, one shorted and the second would fail within a minute. I never made it to the point of needing to draw the schematic. There are some unlabeled components that I would not have been able to identify their value, mostly capacitors (I don't have a capacitance meter).

 

If someone does have access to the schematic, I hope they can post it here for future needs.

 

Again, thanks for the reply. It is appreciated,

Mark

 

[arcadeshopper]

16 hours ago, Ksarul said:

I'm pretty sure the schematic for the QI power supply was included in the bag when Radio Shack was selling them as surplus TI parts in 1984/1985. I'm not sure If I have any bagged ones left to check though. . .

I have one here.. don't see it.. just the volts and pinouts 

[+Ksarul]

I just looked through the 1983 version of the console technical data book as well. It includes the QI motherboard schematics, but the only power supply schematic is the original one.

[+acadiel]

I have like four NIP RS supplies.  If you need one, let me know and you can have it for a decent price plus shipping.

 

[mvancopp]

On 4/3/2022 at 8:47 PM, acadiel said:

I have like four NIP RS supplies.  If you need one, let me know and you can have it for a decent price plus shipping.

 

The offer is appreciated @acadiel but I repaired both QI supplies I have, both were capacitor issues (see above in the thread). Luckily, they were relatively simple issues to track down.

 

Thanks to everyone else for trying. I also looked through different versions of tech docs and repositories I found online, but no luck for QI console supplies.

 

Mark