HP 8563A Spectrum Analyser - display itensity problems - Page 1
Forum section: electronics / repair

author: on4top
author_rank: Regular Contributor
timestamp: December 16, 2016, 08:58:44 pm
content: I got an HP 8563A cheap from an auction .Sadly is has one annoying problem .The softbuttons menu display is unreadable .. the rest looks ok .Looks like an intensity problem .. altough the grid is readalbe also when is press the softkeys the intensity goes up .Some video'shttps://youtu.be/m1Afifr4KjIhttps://youtu.be/ick3-ZGXzRIhttps://youtu.be/jthVIPSRpto

author: KE5FX
author_rank: Super Contributor
timestamp: December 16, 2016, 09:37:33 pm
content: Ditch the CRTaltogether.That's a nice box, and it deserves a nice display.Edit: you might have to use Test Equipment Plus's LCD in that one, I'm not sure if SimmConn supports it yet.

author: on4top
author_rank: Regular Contributor
timestamp: December 16, 2016, 09:44:09 pm
content: Lol yes i know there is an LCD converter kit available ( but $$$$$ )

author: G0HZU
author_rank: Super Contributor
timestamp: December 16, 2016, 11:34:22 pm
content: At work we have quite a few HP8560A/E/EC and 8563E/EC analysers and I've not seen any of the CRT versions suffer like yours. Some of ours date back to the early 90s when we bought a few HP8560A models. They have all seen a lot of use over the years. Some in ATE racks and some in the design labs.So it might just be that something has gone wrong in the Z axis on yours? I've got no experience looking inside this range of portable analyser but I've used them a lot at work over the last 20-25 years. Usually it's the keypad buttons that wear out on these. Very annoying!I have an old HP8566A/B here and an HP8568B and I managed to improve the CRT display on both of these with attention to the Z board. Both of them had issues where the display trace was dim and the focus could not be set for the graticule and the display at a reasonable display intensity. I did this work a couple of years ago and it is still working fine today with a crisp bright display. The HP8566 is an A converted to a B and it has seen a hard life. I bought it as a cheap and tired ex rental unit about 5-6 years ago from one of the top rental companies and the CRT display quality was not good at all. I assumed the CRT was spent and put up with this for about 3 years until I decided to gamble on checking out the Z board components to look for problems. I think I replaced a couple of potentiometers and a resistor and readjusted it all and the CRT quality was simply amazing after this. I did the same changes to the HP8568B and got similar results (but not quite as good).

author: G0HZU
author_rank: Super Contributor
timestamp: December 16, 2016, 11:43:06 pm
content: From memory, the display on the HP8560/3 is a 600x600 grid (as opposed to 10 bit on the HP8566/8) so you might not notice much degradation if you went to a VGA LCD display. However, we have quite a few of the newer HP8563EC models with the LCD (VGA) display and I don't like this display at all. At a casual glance/comparison it initially makes the CRT look tired and dated but the LCD resolution is poor and the colour choice for the grid and trace doesn't suit me. I sometimes can't tell the grid from the trace on the LCD models. It depends on the lighting.If you do manage to restore the CRT performance it might also be worth cleaning behind the glass plate in front of the CRT. This can become dusty/sooty and make the CRT look very tired with a blotchy look to it. But you have to be careful not to let the glass fall to the floor! Do it over a table and not on a tall trolley. I nearly did this to one of my analysers here but managed to catch the plate in mid air as it made its skydiving bid for freedom...

author: simmconn
author_rank: Regular Contributor
timestamp: December 17, 2016, 09:10:41 pm
content: It looks like the 'normal' brightness strokes are not working but the high brightness strokes are. I would take a look at U207 and U210 related circuits, especially R250 and U207A. Artekmanuals has good quality component level information package (schematics) at a reasonable price.The resolution of the spectrum display is reasonably good at 600 points. However many of the units out there are out of adjustment such that the curves look misaligned or segmented. TEP discontinued their 8560A/E kit earlier this year. If you would like to upgrade to an LCD display, you may have to look in the second-hand market, or wait for the SIMMCONN LABS kit.

author: on4top
author_rank: Regular Contributor
timestamp: December 19, 2016, 09:14:16 pm
content: @simmconn tnx for tips !just bought the manual and indeed it's verry good quality pcb level info .Will sure look further in to this ..

author: tipofthesowrd
author_rank: Contributor
timestamp: December 21, 2016, 09:20:34 am
content: It could just be dirt behind the glass display.In these analyzers the air flow really creates a mess at the edges of the screen.Especially if they were in an ATE rack for a long period of time.

author: on4top
author_rank: Regular Contributor
timestamp: December 21, 2016, 02:36:06 pm
content: Removed the glas plate and cleaned the CRT and Glas plate .Much cleaner now .. but the problem stil exist ofcourse .Also noticed "some" burn in on the crt tube .Checked R250 ( 3,1 Mohm looks ok ) Will need further debug of this circuit .

author: G0HZU
author_rank: Super Contributor
timestamp: December 21, 2016, 07:02:13 pm
content: QuoteRead my post again. I suggested cleaning the glass AFTER the original CRT problem had been repaired and the CRT display restored to normal operation. Even on a healthy CRT the glass gets quite grubby and I would recommend cleaning the plate every few years. The CRT display on these analysers can look very tired and blotchy once the analyser is quite a few years old and cleaning the glass makes a big difference.It would have been nice if the original CRT display problem had been fixed first because that way the full benefit of the glass clean would have been noticed. I've seen and used a LOT of these analysers over the years in my day job. Much more than most people on this forum and I'm just giving the OP the benefit of my experience with them.

author: simmconn
author_rank: Regular Contributor
timestamp: December 22, 2016, 12:52:29 am
content: Quote from: on4top on December 21, 2016, 02:36:06 pmR250 should be 3.16M Ohm, not 3.1 ohm. It's hard to tell if it is okay just by looking at it. Also the analog switch U207 is known to go bad after so many years in service. The Artek manual's pdf has some schematic symbols missing, making it harder to interpret. The original paper copy was said to be like that.

author: on4top
author_rank: Regular Contributor
timestamp: December 22, 2016, 02:48:40 am
content: @simmconndesoldered r250 and measured it 3.16 MOhm ( typo in other reply )U207 seems this chip Analogue Switch ICs SWITCH 4X SPST N.C. 16CDIP EXTCOMhttp://www.mouser.be/ProductDetail/Intersil/HI1-0201-4/?qs=9OuAwqlOLJHN%252b1B22dDGNA==http://www.mouser.com/ds/2/465/fn3121-79366.pdfseems not widely available ( if it is bad )edit : according to digikeyhttp://www.digikey.com/product-detail/en/intersil/HI1-0201-4/HI1-0201-4-ND/1062211HI3-0201-5Z-N should be a drop in replacement ..http://be.farnell.com/intersil/hi3-0201-5z/ic-switch-analog-cmos-spst/dp/1561982?ost=HI3-0201&selectedCategoryId=&categoryNameResp=Alle%2Bcategorie%25C3%25ABn&searchView=table&iscrfnonsku=false

author: on4top
author_rank: Regular Contributor
timestamp: December 29, 2016, 12:03:01 am
content: replace u207 today .. problem stays . ( soldering an ic socket .. now original chip back in )

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: December 29, 2016, 09:33:04 pm
content: Watching this closely, I have an 8560A that looks pretty tired and fuzzy...

author: simmconn
author_rank: Regular Contributor
timestamp: December 30, 2016, 06:01:13 am
content: Quote from: on4top on December 29, 2016, 12:03:01 amI would run some basic tests to confirm that U207 is bad before reaching for the desoldering gun. First check if the switch control signal is toggling. If it does not, trace it up and see where the signal stops. Then I would short the switch in question and see if the intensity improves. If it does not, the problem is likely not with the switch but in the downstream circuit.

author: deepskyridge
author_rank: Regular Contributor
timestamp: December 30, 2016, 08:07:04 pm
content: I had a HP 8591E with a bad display module, badly burned CRT and other issues. I picked up a brand new module from this seller on Ebay for $50.http://www.ebay.com/itm/1-Qty-LOT-NEW-HP-Agilent-2090-0539-CRT-Display-Section-for-8590-Spectrum-Analyze-/351781522402?hash=item51e7d00be2:g:oEYAAOSw~FNUY7~qThis was a simple replacement and took about 30 minutes.Mabye this will fit your 8563A SA.Gary

author: carl_lab
author_rank: Frequent Contributor
timestamp: April 04, 2017, 01:02:00 pm
content: We have a 8591E with bad display (dark screen).I've checkeded +5.1V, +12V, +15V, -15V at TP401-TP404 (OK).What can I check at the display module?

author: DC1MC
author_rank: Super Contributor
timestamp: April 12, 2018, 08:56:39 pm
content: I'm resurrecting this topic, I have an HP8560E, after repairing the power supply, I have the EXACT issue as the OP, did anyone manage to solve it or the old X-Ray cannon (CRT) is done for ?Strangely the display is nicely focused, and the highlighted alphanumeric is clear and crisp, also reasonably luminous.Please help or the SA is going to be mercifully sold !!!Thank you for your help,DC1MC

author: charlyd
author_rank: Frequent Contributor
timestamp: March 20, 2020, 08:57:23 am
content: Hello in response of this topic in post #11 there are 2 screenshot i ordered te manual from artek manuals but got a 8560E clip without outlines so i delete the bunch and now i am looking for a manual like ON4TOP posted . can somebody help me out. it is for my 8563E unit.my tube has the textboxes nearly visible… and when it is powered on let say 10 minutes they are not visible anymore.but the help tekst and highlited items are very good visible. for example the marker is very very bright.. and the line in the bottom also..it this my tube or not?? let turn the question different who can i easy find out that it is the tube and not the raster.or the other way arround.

author: charlyd
author_rank: Frequent Contributor
timestamp: October 05, 2020, 01:09:47 pm
content: LEts open up this one again. we are more then 6 mnd past and i managed to fix alle errors in the unit except the CRT/TUBE problem. i got in a swap tube from "...." ( name will come here if i don t get response). but i got a tube for $150 which was more dead then my own tube. nearly no visibilty.i think i have to start diagnosing the circuitry to the tube. With my own tube it start let say not bad. but after 15 minutes. one part of the text is faded. the other not. when i bring up the Firmware en revsion page it show with very much intensity and looks ok.i can drop some pictures here to be more precise.

author: charlyd
author_rank: Frequent Contributor
timestamp: October 05, 2020, 02:55:21 pm
content: i found some display response, intensity on te line generators arround U210 ( what simmcon says) but can not find any clip[ manual from the A2 board.. any hints? i have so much manuals from the 856X that i am a bit lost...

author: Miti
author_rank: Super Contributor
timestamp: October 05, 2020, 04:16:35 pm
content: Quote from: charlyd on October 05, 2020, 02:55:21 pmI assume you know there’s a brightness adjustment somewhere in the menus.

author: charlyd
author_rank: Frequent Contributor
timestamp: October 09, 2020, 05:51:14 pm
content: yes miti, the intensity is set to 255 in the menui am looking for the 8563A clip.

author: charlyd
author_rank: Frequent Contributor
timestamp: October 19, 2020, 03:04:04 pm
content: ok i found a schematic from my A2 controller and when probing arround U207 i discovered that when i short pin 2 and 3 of the Harris switch (it is written in an other manual to short out the switch pins) my picture looks ok.getting the source of so called "DEF1" line it starts from a 74hct377 ( U507 ) and is TTL lvl. 5 volt. while the switch is -15 and +15 connected. so i am not really 100% sure if the switch is enabled on pin 1 with the 5 volt.anyone probed arround in (M) area where U207 and U210 are located lately?

author: George Edmonds
author_rank: Frequent Contributor
timestamp: October 19, 2020, 08:18:39 pm
content: HiThe problem with a CRT display that loses intensity after a number of minutes is usually caused by a high value resistor going up in value due to the applied voltage across it. Normally this only occurs with resistors say over 100K, but I have occasionally seen it with lower values.George G6HIG

author: charlyd
author_rank: Frequent Contributor
timestamp: November 01, 2020, 09:40:36 am
content: i spended an other few hours on my display problem again. First of all, the following post i found on Keysight forum, keeps me away from the thought my CRT is the problem.----------------------------Q:I have an 8563A that powers up OK but the display stays blank. It shows a green flash when powering down indicating a normal field collapse.I have checked all the DC power supplies and also the signal levels on J201 202. Also the ext video out produces some output on a scope.HV module substituted and A17 driver with no effect.I suspect it is the CRT, is there any way to confirm this?A:If you saw the green flash when turning the power off then your CRT is probably OK. I'd suspect the A2 controller (especially since your HV and driver assemblies seem alright)----------------------------I also see the green bright flash/spot in my CRT when powering off so that answer sound reasonable enough for me to continue and when i poke arround U210 with my probe i see my text boxt on the right and bottom side light up as they should. So there is hope i would say...In the following weeks, i decided to take out U207,U210 & U211 and put them in (high quality) round-pin IC-sockets for easy probing. I also took out the R250(3M16) resistor and R266(1M47) but that checked ok.Shorting the switch U207 pins 2 and 3 my picture looks ok. So i decided to pull pin 1 out of the socket and traced down the switching line from 74HCT377-> DEF1.the line was high where i suspected a low to enable the U207 switch.Meanwhile some part came in which i ordered over a month ago. A Harris HI-> U207 and two MC34084B -> U210 and U211. I did a quick swap but without any succes.i checked my +15VF supply voltages, but they are just +14.92 and -14.91. quit on the low site if you ask me. Normally i would suspect a few .1 over the printed values in the Manual but these are below.. not much but.And my DEF1 line is high which open the U207 1,2,3 switch. strange..suggestions?i am also curious what exactly to be expected on the line (-U207B/P7- U207A/P3 - U210D/P13 see marked in picture.)

author: charlyd
author_rank: Frequent Contributor
timestamp: November 11, 2020, 11:33:58 am
content: This is the result of pulling the U207 pin 1 out of the socket or pin 8 -DEF1 line. then the picture on the tube looks very ok.[Closed the other topic]https://www.eevblog.com/forum/repair/hp8563e-repair/msg2989588/#msg2989588

author: charlyd
author_rank: Frequent Contributor
timestamp: January 29, 2021, 01:17:53 pm
content: hello anybody who can probe arround and tell me the voltages arround the U207B switch and the DEF1 line.for example is the +14.92 ok or should it be like 15.03v or what ever.and what about the DEF1 line when should it be high? when i would have had Option 7 in the unit then DEF1 would be ok the manual states,i am also curious what exactly to be expected on the line (-U207B/P7- U207A/P3 - U210D/P13 see marked in picture.)

author: dxl
author_rank: Regular Contributor
timestamp: March 18, 2021, 07:39:36 am
content: Hi Charly,have you fixed that problem?I would check the Display RAMs U201/U202 - what makes me suspect them is that the lines in the background grid are not really connected - is that only in the pictures? And the horizontal line in the test picture should be one line, but in your picture it looks like two diagonal lines crossing each other.The intensity information is encoded with some commands in Bits 14,13 and 12 of the Display RAM.I would check whether the Address and Data lines on the RAMs are looking good, and maybe swap U101 and U102 and see whether something changes.

author: charlyd
author_rank: Frequent Contributor
timestamp: March 19, 2021, 04:35:38 pm
content: Hi thanks for the info. I will check this as soon as i ended my TDS7404 project which is al over the bench now... very happy with the tip! great....will comment back here.

author: charlyd
author_rank: Frequent Contributor
timestamp: July 31, 2022, 08:03:11 pm
content: @dxl i did a replace of my both U201/U202 or U101 and U102video ram chips, now socketted.but that didn t fix the display issue. any other suggesties?

author: charlyd
author_rank: Frequent Contributor
timestamp: September 25, 2022, 07:03:53 am
content: Hi i want to re-open or refresh this topic because it was never fixed yet.can someone do some measuring arround U207 (or the Y or Z output board) or the +15VFfor me on a unit with a good working display?thanks in advance