Anritsu SiteMaster S322D with defective Option 21 - Page 1
Forum section: electronics / repair

author: vdsl
author_rank: Contributor
timestamp: February 14, 2020, 08:21:42 pm
content: HiI have an old SiteMaster which has Option 3 and Option 21.The unit has the following problems:- Option 21 (transmission measurement between the two ports) is not showing up and cannot be used.- Batterys are not charged, when inserted. Only Power from external source is working.I would like to use Option 21.Can anyone point me in the right direction, where I can find some documentation? Maybe schematics? Or can anyone assist me in trouble shooting?I found the Maintenance Manual, but this does not help very much.Any help is much appreciated.Cheers

author: SMdude
author_rank: Frequent Contributor
timestamp: February 15, 2020, 07:09:58 am
content: I have one of these. I don't think I took any photos of the insides though.If you put up some photos I might be able to point you around the battery and power supply area.Or is your battery just dead? You should be able to measure some voltage at the battery connector.The positive terminal is next to the notch that is cut out and negative on the outter edge. Perhaps try and manually charge it with a 500ma 12v supply for a while and monitor it.For option 21, seeing as it is not coming up in your option list when booting then perhaps it is not installed? Or the eeprom was corrupted? Is it just a software unlock of the already existing hardware?

author: vdsl
author_rank: Contributor
timestamp: February 18, 2020, 02:33:59 pm
content: Quote from: SMdude on February 15, 2020, 07:09:58 amI will open the unit and post some photos shortly.QuoteThe battery is OK. Altough it does not get charged by the unit itfself, I charged it outside and it is fully charged. The funny thing is, as soon as I input the battery into the unit, it powers on by itself.And its not possible to switch it off. The button has no effect. I have to take the battery out, to shut it down completly.Quotehmm, i not 100% sure that it needs to display at the startup. It just found it odd, that Option 3 is display, but not 21.When you go into the "Modes" screen. What do you see?Thanks alot already!

author: vdsl
author_rank: Contributor
timestamp: February 18, 2020, 04:51:38 pm
content: As requested some pictures of the inside.

author: SMdude
author_rank: Frequent Contributor
timestamp: February 19, 2020, 12:13:04 pm
content: On the mode screen, I see:Freq -SWR, return loss, cable loss - 1 portDTF- SWR, return loss, opticalSpectrum analyzerThe actual power supply is on the bottom side of the board, not far from the power supply dc jack. I would say that the power switch would be near there too as well as whatever switches power to the battery during charging. It sort of sounds like it's got a shorted fet or something.Also you will note that there are several power supply test points on the top side of the board.Cheers

author: vdsl
author_rank: Contributor
timestamp: February 20, 2020, 11:31:05 am
content: OK, I see the same. So there should definately be more, when the unit has Option 21.I managed to open the unit further.One needs to remove the main SMA and then gently pry the board out with, as there is a multipole header connected to it from below.I made some photos. Check there section where the battery comes in. (right by the U8) marking on the photo batteryInput.

author: vdsl
author_rank: Contributor
timestamp: February 20, 2020, 11:31:42 am
content: Here is the section where the power from the external wall adapter comes in.

author: vdsl
author_rank: Contributor
timestamp: February 21, 2020, 08:00:01 am
content: Question:Should be no problem if I power the board without it plugged into the lower board with all the RF stuff?I mean, somehow I need to test stuff.. when its plugged in, there is no acces, but the testpoint on the top layer..What do you guys think?

author: SMdude
author_rank: Frequent Contributor
timestamp: February 21, 2020, 08:18:37 am
content: It should be alright to have power connected. I had to do troubleshooting on the power supply section in mine and had it powered on(power applied) whilst doing so.I'd be tracing the battery back to see what it connects to.Try and find parts with a similar refdes to the other power supply stuff. They normally number by section, eg r1xx C1xx etc depending what group of the schematic they belong to.