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SiriusHardware · 9th Jan 2023, 12:21 pm

I now have the PCB assembled as far as it needs to be but my SMPSU for the 5V / 10.5V SMPSU regulator is not running (at either voltage). Instead, the voltage at D1 Cathode is 4.867 which is just the +5.00V supply being dropped across D1.

The first thing I have to suspect is that the reg ICs I've been supplied with for the IC5 position are not actually what they are supposed to be - on looking up the code printed on them they have 'S518' marked on them, which on a brief search comes up as a transient suppressor. Chris O, if you read this, I would be interested to know what the marking is on your IC5?

(Edit - Actually the marking on mine is 'S51B' which is indeed what it should be for the LM2731Y according to the Ti datasheet. Of course, mine could still be fakes.)

9th Jan 2023, 12:21 pm	#72
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,553	Re: Tesla Programmer I now have the PCB assembled as far as it needs to be but my SMPSU for the 5V / 10.5V SMPSU regulator is not running (at either voltage). Instead, the voltage at D1 Cathode is 4.867 which is just the +5.00V supply being dropped across D1. The first thing I have to suspect is that the reg ICs I've been supplied with for the IC5 position are not actually what they are supposed to be - on looking up the code printed on them they have 'S518' marked on them, which on a brief search comes up as a transient suppressor. Chris O, if you read this, I would be interested to know what the marking is on your IC5? (Edit - Actually the marking on mine is 'S51B' which is indeed what it should be for the LM2731Y according to the Ti datasheet. Of course, mine could still be fakes.) Last edited by SiriusHardware; 9th Jan 2023 at 12:28 pm.