Saunders and Associates 150b crystal impedance meter - Page 1
Forum section: electronics / repair

author: ralphk
author_rank: Newbie
timestamp: February 26, 2018, 08:44:41 pm
content: I have one the crystal impedance meters and is simply reading all 0's or F's on the display. I don't have a manual or service manual either. I've google searched for a manual to no avail, and so far my voice mails to the company have gone unanswered. If anyone has a copy of a manual, or even better, a service manual it would be incredibly useful before I attempt a repair. Thanks,Ralph

author: floobydust
author_rank: Super Contributor
timestamp: February 27, 2018, 12:21:06 am
content: All I could find isBrooke Clarke's website PRC68.com, with 150C and 150B he says "the diagrams in the on line 150C manual are unreadable." You might ask what he's got.

author: edpalmer42
author_rank: Super Contributor
timestamp: February 27, 2018, 01:23:28 am
content: Have you looked at the manual for the 150C? It may or may not be very similar to your 150B.Ed

author: ralphk
author_rank: Newbie
timestamp: February 28, 2018, 06:41:29 pm
content: Thanks Ed and floobydust for the tip to look for the 150c manual. I was able to find a high quality pdf after google searching for the 150c and it is at userequip.com. A cursory glance looks like the units are indeed very similar, should get me a long way to troubleshooting what the problem is.Regards,Ralph

author: (*steve*)
author_rank: Regular Contributor
timestamp: April 28, 2018, 04:02:59 pm
content: I have one of these (the 150b) and it seems to work for a short while before the display changes to 5E5Exxxx (xxxx seems random). Even after powering down and back up I get 5E5E0000.I have a massive 208 page 150C manual, but I don't see a mention of this.edit: Oh, if I press all three switches down before the unit fails it shows CCCCCCC6, which I think indicates mode 6. I also can't seem find out what mode 6 is...edit 2: Three filter caps on the power supply (100uF 50V) were dead. Measured 72uF 4R3 ESR, 42uF 69R ESR, and completely open circuit. After replacing these with 220uF 63V low ESR caps, the display is less flickery, measurements seem more stable, but it still stops after a while with 5E5Exxxx. However, the three terminal regulators seem VERY warm. Are they shutting down? There's more caps in the power supply, I think I'll replace them all. I'm thinking that the device is either drawing too much current or the switching regulator providing an input voltage to the regulators is running at too high a voltage...

author: alocam
author_rank: Regular Contributor
timestamp: July 11, 2018, 12:38:51 am
content: Hello, I was searching info related to the 150 series, and found this thread. I guess I have downloaded the 150b service manual, I should have to dig in my server a bit, but may be you have already got such info. In case you didn't, let me know and I'll try to search the pdf file.Regards

author: rizal5478
author_rank: Contributor
timestamp: September 28, 2018, 06:05:12 am
content: Quote from: (*steve*) on April 28, 2018, 04:02:59 pmHave you solve this issue?

author: (*steve*)
author_rank: Regular Contributor
timestamp: January 29, 2020, 10:08:41 am
content: Sorry about the delay in responding.No, I have not resolved the problems.

author: scopeman
author_rank: Frequent Contributor
timestamp: February 21, 2020, 04:46:11 am
content: I bought one of these years ago that had similar problems. IIRC replacing the 8031 microcontroller fixed the problems.SamW3OHM

author: rwweichler
author_rank: Newbie
timestamp: July 24, 2022, 01:13:10 pm
content: Hello,on the search for someone who might be able to help me in repairing my Sanuders & Associates 150B I came across this blog.Mine got a shorted capacitor across the +15 V and the -15 V lines (namely OC56 across the measurement oscillator's output stage) and, in consequence the +5V line raised significantly. Thus, quite some logic ICs were damaged, among them are the two EPROMs. I didn't take a backup of the EPROM files, shame ...All the "historic" ICs are still available at eBay and even Digi-Key, but with the firmware I'm in a difficult situation.So I kindly ask whether you can help me out with a copy of your Firmware files. Ideally you could provide the FW version on the EPROM stickers and the serial number of your instrument just to see how far way it might be from mine (FW 1700, S/N 0468, build date appr. 1980 / 81 according to date codes).Thanks already for your consideration and kind regards,Rolf

author: Mantrid
author_rank: Newbie
timestamp: October 31, 2024, 10:06:28 pm
content: Hello everybody! I have EEPROM dumps for the device discussed in this topic,SAUNDERS 150Cwith some options004and009. Twoi2732Achips or its analogues from other manufacturers,ID3andID4, respectively. Does anyone need them?