UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Retired Texas TI99/4A engineer needs help please.

Boater Sam · 22nd Oct 2018, 10:42 pm

Within a few tens of millivolts, yes I am getting 5v, off load, but I did when the TIP31 was O/C as well. The resistor only burnt out when the rail was loaded.

The logic powers up but there is massive data corruption, like a line hold fail, the screen is unreadable.

I need to take stock, follow up on all the suggestions and scope the output.
I'll be back. Thanks for giving me the pointers.
Sam.

22nd Oct 2018, 10:42 pm	#16
Boater Sam Banned Join Date: Dec 2013 Location: Middlewich, Cheshire, UK. & Winter in the Philippines. Posts: 3,897	Re: Retired Texas TI99/4A engineer needs help please. Within a few tens of millivolts, yes I am getting 5v, off load, but I did when the TIP31 was O/C as well. The resistor only burnt out when the rail was loaded. The logic powers up but there is massive data corruption, like a line hold fail, the screen is unreadable. I need to take stock, follow up on all the suggestions and scope the output. I'll be back. Thanks for giving me the pointers. Sam.