Just bought a T962 flow oven.


I have read about problems with its TC sensor. Apparently the IC and its reference junction are too close to the oven. I think I can solve that and also have a back-up controller on its way from Malaysia. Somehow DHL decided to ship through Frankfurt, Germany., which is where it is today.

I need to get some solder paste. I am a real fan of Kester, but at $14 per syringe for 63/37, I am wondering about others' experience with the cheaper stuff.

I have also tentatively planned to get stencils for major IC's (e.g,, 44 pin TQFP or QFN) and rely on little dabs for most other things.

It's a totally new experience for me. Any comments?

 

This is a good start...
https://github.com/UnifiedEngineering/T-962-improvements

 

I have been trying to get into bootloader mode for several days. A person, "skeezix," on github posted a very similar problem (see: Unified Engineering/T-962-improvements/issues/104) that was solved. That solution didn't work either.

The controller is an NXP LPC2134/01. What bothers me is that the TX pin (P0.0, #19) idles low. Resistance to ground (turned off) is about 145 Ω. When on or off, the RX line of the FTDI TTL adapter is pulled low. It is a dead short from that pin to the corresponding pin of the ISP header.

Signals have been 'scoped on the FTDI TX line and they are correct (i.e., "?"). The LPC2134 simply does not respond. I tried a pull-up to VCC with 4.7K, and that did not change the low-idle state.

Is anyone familiar with that chip or the oven enough to comment on the low-idle?

I have inspected the board, cleaned it and find no shorts. I had false hopes raised yesterday when with a high-intensity LED behind the board, I saw a shadow. That turned out to be a blob of flux.

Link to LPC2134 datasheet: https://www.nxp.com/docs/en/data-sheet/LPC2131_32_34_36_38.pdf