Hi, I've spent a couple of weeks tinkering with a x0xb0x kit I bought from x0xsh0p.de and so far I have got up to building the power supply section. Everything went well, I had a few issues, but I now have 11.98v on pin 3 of J4 and 5.33v on pin 1. However there is some weirdness that has been introduced that I wanted to see if anybody had any ideas on what has caused this?
Initially I was getting a low 5.33 reference voltage, I was getting 5.32vdc max using the trimpot TM6. During troubleshooting I desoldered IC22 (LM317) and during this one of the legs broke so I ordered a couple replacement from ebay (marked LM336 Z50 HLF18). I have soldered some wires connecting to the pas for R5 and IC22 and put these components in a breadboard. Now during testing I am still getting low voltage (4.11 - 4.73vdc), and I notice that the trimpot seems to be reversed so that all the way clockwise gives a lower voltage than all the way anti-clockwise. I did not resolder the trimpot, and I assume it is in correctly matching the triangular pins, so I don't know why it is now back to front. Any ideas?
Also to make a temporary fix I looked to alter R5 from the 2.4k, finding that I had to up it to 10k which 5.22 - 5.90. Again this seems reversed to what other posts on the forum suggests - I was expecting to have to drop the resistance.
I have carried out the tests from the fab manual along the way:
Across jack = 10.6vac
C5 = 14.55vdc
C3 = 14.06vdc
C6 = 4.98vdc
C1 = 5.98vdc
D44 - D47 showing a reading of 635 on my multimeter in diode mode, in one direction only
From GND R179 with R5=10k:
D47 5.9/5.4 15.4v,
Guessing not a problem as long as can adjust TM6 and have 5.33v and 12v, but anybody have any ideas? Thanks, Will