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eHam Forums => Elmers => Topic started by: N3DT on November 11, 2012, 05:17:14 PM



Title: R 2005D Motorola service monitor help
Post by: N3DT on November 11, 2012, 05:17:14 PM
OK, left it on overnight and I'm sure the fan isn't cooling it off enough, sure enough in the morning, it's not working.  AC light comes on, but that's all.  Haven't tried running it off 12V yet.  Undoubtedly a power supply problem, but I don't have a service manual or anything on it.  All boards modular, so very hard to trouble shoot except just looking at parts by pulling boards out, can't see anything burned.  No AB smell.

Anyone have any ideas.  I see a Chinese gentleman on evilbay is selling a 2001/2002 service manual cd, but I don't know how similar they are but for $15?

Dave
N3DT


Title: RE: R 2005D Motorola service monitor help
Post by: N4NYY on November 11, 2012, 05:25:19 PM
Try to run in on 12V. It it works, then you know it is the power supply. You can likely rebuild it without a schematic.


Title: RE: R 2005D Motorola service monitor help
Post by: WB6DGN on November 11, 2012, 07:37:21 PM
Quote
I see a Chinese gentleman on evilbay is selling a 2001/2002 service manual cd...

Dave,
The 2005D is a 2001D with the options denoted by the last two numbers of the model number unlike other manufacturers who list their options separately.  The 2005, 2021, etc. are all the basic 2001 instrument.  What does matter, though, is the revision letter, in your case "D".  The "D" revision has some significant changes over the A, B, and C versions and the manual needs to match.  Hope this helps.
Tom


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on November 13, 2012, 11:26:05 AM
I'm going to try over at batlabs.com, maybe one of the Motorola guru's will know something.  I know Motorola sold their service monitor division to General Dynamics when I was still working around 04 or so, so I may try to see if GD has any information.  Motorola tech is no help.

I've traced the AC to the power supply board and am trying to figure out the dc outputs, at least that may get me somewhere.

I still don't understand the dc input circuit with the fuse, one side of the dc fuse is connected to ground, unless they're fusing the low side?  I'm not putting any dc power to it until I know what I'm doing.

Dave


Title: RE: R 2005D Motorola service monitor help
Post by: KB5ZSM on November 15, 2012, 12:30:58 AM
If in fact it is a thermal problem, try using freeze spray to isolate the problem area and maybe the faulty component.


Title: RE: R 2005D Motorola service monitor help
Post by: W9GB on November 15, 2012, 04:32:46 AM
http://www.cardinalelec.com/index.htm


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on November 15, 2012, 08:17:48 AM
If I had any clue where the problem could be, I'd use the freeze spray, but at the moment nothing is working and there are about 15 daughter boards, one large mother board.  Thanks for the Cardinal link, but I could take it to the Motorola depot in Upper Marlboro, MD instead of shipping a 70 lb container to Chicago.  I may end up doing that if I can't find a schematic or service manual on it.  It would probably be worth a couple hundred just to get it working, if they will even work on it, and they may not since Motorola has sold their service monitor division.  I'd probably have to find a General Dynamics service depot.  But I'm going to hold out until I find out anything from Batlabs.


Title: RE: R 2005D Motorola service monitor help
Post by: WB6DGN on November 16, 2012, 12:33:17 AM
Quote
Thanks for the Cardinal link, but I could take it to the Motorola depot in Upper Marlboro, MD instead of shipping a 70 lb container to Chicago.  I may end up doing that if I can't find a schematic or service manual on it.

I doubt if GD would work on a monitor of that age; not sure about Mot. if they still have service facilities available or not.  The last company I worked for used Cardinal and their service was very good.  My own preference, however, is Amtronix in northern New York,  http://www.amtronix.com/ .  I believe he works on Motorola though his specialty is Agilent/Hewlett-Packard.  If GD or Mot. does work on it, hold on to your hat! as far as price goes.  Doubt you'll get out of either for less than a couple thousand, maybe more depending on what they find.  For example, a new CRT, last I heard, is around $1250 for the part alone!  The independent shops are going to be a lot easier on your wallet but still pricey.  Doubt you'll get anyone to even plug it in for a "couple hundred", though.  Good luck; when you're dealing with "high end" test equipment, you're in the big leagues and pay accordingly.
Tom


Title: RE: R 2005D Motorola service monitor help
Post by: NJ1K on November 16, 2012, 04:30:24 AM
I have a full service manual for R-2001D.  It's not for sale but I might be able to help with specific information.

email me at mycall at sparkarc dot org


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on November 16, 2012, 06:57:42 PM
wb6dgn,  yes, I was thinking that if I took it for repair it would be very expensive, and undoubtedly Mot will not work on it as they have sold the monitor rights to GD.  And they would be very expensive too.  I'm thinking my best option is buy the D model CD from a guy on evilbay for $75 and bite the bullet.  I understand there is a good section in the manual about trouble shooting no power up.  I'm pretty sure it's a power supply issue, but not sure, but I did discover A3 is the DC output module and I have no voltages on the TP's there.  That's a pretty good indication along with absolutely no function except the AC LED on the front panel when I plug it in.

I'm hoping I can find a fuse, but good luck on that one.  I've been through the power supply boards pretty thoroughly, but somethings not working.  Probably a transistor or two.

Dave


Title: RE: R 2005D Motorola service monitor help
Post by: WB6DGN on November 16, 2012, 11:58:56 PM
I'm not 100% certain that Mot. has closed their test equip. depot.  Seems to me I read recently that someone sent something there.  Not having any Mot. test equipment, I didn't pay much attention, though.  Probably moot anyway as, you're right, the prices would be very high.
There is a retired Motorola test equipment tech. that frequents the Test Equipment thread on Bratlabs that might be able to offer some advice while you're looking for a manual.  He seems to be very helpful and knowledgeable and may well be able to steer you in the right direction.  If you could get this problem fixed without having to buy that CD, I think I'd think twice about buying it because of the very limited parts availability for that series.  Nothing more frustrating than knowing what's wrong and not being able to get the part.  'Course, another option might be to look for a "parts donor" monitor to keep things going for (maybe, quite) a while.  The killer is the CRT.  When it starts going dim, you know its days are numbered.
I like that series monitor, though.  That's the monitor that I used in the portable shop (mine was a 2021 with the trunking options) until the day I retired.  Good luck with it.
Tom


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on November 17, 2012, 05:51:47 AM
By the time I quit working in 05, Motorola would not accept any service analyzers for repair or calibration.  We had to go to GD, apparently they sold all the rights.  Not to say an independent shop wouldn't take care of it.  It may be that working boards are rare as hens teeth, but I'm sure components could be sourced or substituted, except maybe the CRT.  It's certainly worth fixing if possible.  I've read that people at batlabs have been happy with the CD from the guy on ebay, so I may go that route in case something happens in the future.  The machine is certainly worth $75.

Thanks
Dave


Title: RE: R 2005D Motorola service monitor help
Post by: WB6DGN on November 17, 2012, 07:47:41 PM
Quote
...so I may go that route in case something happens in the future.  The machine is certainly worth $75.

Its a darn shame that so much nice equipment is compromised by lack for replacement parts (really lack of mfg. support).  Wonder if someone could make a profitable business out of supplying replacements for such "no longer supported" equipment?  World, remember that old saying, "Waste not, Want not."  This world sure needs to be less wasteful.
Tom


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on November 23, 2012, 08:08:07 AM
Well, I've found a diode that was a dead short in the low voltage power supply.  I'm going to replace all 4 diodes in the bridge and hopefully the thing will come back on.  I did discover that if any of the power supplies are shorted, or even high or low voltage, it's all monitored and the control board will shut everything down in that case.  We'll see.  Parts should be here Monday or Tuesday.  I got the service manual from 'southern cross' on the ebay, it was a bit pricy, but I guess worth keeping the analyzer going.  At least it's perfectly readable/printable.


Title: RE: R 2005D Motorola service monitor help
Post by: KE3WD on November 23, 2012, 08:26:56 AM
Well, I've found a diode that was a dead short in the low voltage power supply.  I'm going to replace all 4 diodes in the bridge and hopefully the thing will come back on.  I did discover that if any of the power supplies are shorted, or even high or low voltage, it's all monitored and the control board will shut everything down in that case.  We'll see.  Parts should be here Monday or Tuesday.  I got the service manual from 'southern cross' on the ebay, it was a bit pricy, but I guess worth keeping the analyzer going.  At least it's perfectly readable/printable.

Very likely that will be all that is wrong with it. 

Good troubleshooting, sometimes just takes a wee bit more time, patience and the willingness to look for it, but as I told you above, suspect the power supply. 

"Follow the power, follow the power, follow the power!" 

Squidmatic not necessary for that. 


73


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on November 23, 2012, 01:33:54 PM
The schematic did help.  I was thinking one of the TPs was at ground, but the track just looked like it went to ground.  Schematic confirmed that it was not at ground and when I removed some parts and traced the track it was apparent there was a short to ground.  And any shorted supply will shut the whole thing down.  I was pretty sure it was a power problem since there were no voltages anywhere.


Title: RE: R 2005D Motorola service monitor help
Post by: K7LZR on November 28, 2012, 02:26:53 PM
Hope that's all it was. I used an R2014D for a long time, loved it. Now I use an HP 8924c, which is a very capable lab-quality instrument but must stay on the bench cuz it weighs 59 Lbs.!!!

- Darrell/K7LZR (formerly KA7BTV)


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on December 01, 2012, 07:15:03 PM
The diodes got rid of the short on the A5 board, but it's still not working.  I've been printing out the circuits of the individual boards, and the block diagram of the power supply, but there are voltages missing that appear to be shut off from the control board, and that one is very hard to figure.  I'm still hoping it's something in one of the power supply boards and not the control board.  I've got big pages of schematics and diagrams all over the work area trying to sort through it.  This may take a while.  There are plenty of mistakes in the book too that I've been going through and correcting.  Not unusual from what I've seen in the past.

I still need to try the DC supply and will do that next.  It may be the AC switching FETs.

Dave
N3DT


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on December 03, 2012, 05:51:34 PM
The DC input doesn't work either.  I'm getting more and more convinced that the A4 Control Board is shutting things down for some reason.  I need to make an extension board so I can trouble shoot the board with voltages on it.  I'm going nowhere shooting in the dark.


Title: RE: R 2005D Motorola service monitor help
Post by: KE3WD on December 04, 2012, 05:05:05 AM
Can you disconnect boards one at a time and then check to see if power comes up on the dead lines from power supply? 


Title: RE: R 2005D Motorola service monitor help
Post by: K4JJL on December 04, 2012, 08:26:51 AM
I would think a shorted diode would blow a fuse.  Did you check all those?

Also, I had a mica capacitor short and explode inside a 2001D.  Horrible smell.  Might check for some of those gone bad, too.


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on December 14, 2012, 06:39:40 AM
I've found a bad LM339 comparator on the A4 Control board, the AC/DC overcurrent circuit.  It's shutting down the PWM on the shutdown pin.  I've got some parts on order, but when I replace the 339 I want to add a socket, so I'm waiting for that.

I've got all the extra boards pulled up and if this gets the PS working, I'll put the boards in one by one, but we'll see.


Title: RE: R 2005D Motorola service monitor help
Post by: KA5IPF on December 14, 2012, 08:13:02 AM
Never use a socket. The odds are the socket will cause problems long before the IC will fail again.

My 2 cents.

Clif


Title: RE: R 2005D Motorola service monitor help
Post by: NJ1K on December 14, 2012, 09:28:51 AM
I have never had a chip socket fail....


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on December 14, 2012, 06:55:38 PM
Well, I didn't get cheap sockets, I got the open frame Aries sockets with solid gold contacts.  16-3518-10  I'm sure they will be good.


Title: RE: R 2005D Motorola service monitor help
Post by: KE3WD on December 15, 2012, 07:20:34 AM
"Never say, 'never'"...

<g>


Title: RE: R 2005D Motorola service monitor help
Post by: NJ1K on December 15, 2012, 08:14:49 AM
"Never say, 'never'"...

<g>

So, out of the hundreds of millions of sockets in use out there, what percentage of these sockets might have caused problems?  And if they are such a problem, why do thousands of manufacturers still use them?  Oh, I suppose if one submerged the board in water, the socket might likely fail before the chip actually does, but I don't usually submerge my circuit board in water. 


Title: RE: R 2005D Motorola service monitor help
Post by: KE3WD on December 15, 2012, 12:29:56 PM
NJ1K --  You weren't the first to use the word in this thread, and I wasn't pointing that at you.

If the man wants to socket the board, that's fine with me, have done the same *many* times myself.


73


Title: RE: R 2005D Motorola service monitor help
Post by: WB6DGN on December 15, 2012, 12:37:59 PM
Quote
Never use a socket. The odds are the socket will cause problems long before the IC will fail again.

There was a time when that was pretty generally true but, as the OP noted, there are quality sockets available.  Especially in this case where he expressed some uncertainty whether he'd found the whole problem.  If he didn't and the IC failed again, he'd be tempting fate by having to remove it again to replace it a second time, especially if he's not using a vacuum desoldering tool.  In this case, I think his choice is a good one.  There are times when a socket is still not a good choice such as with very high frequency signals but that is not the case here.  Good luck with it.  I used a version of that monitor for the last eight years before I retired.  When they're working right and have a good bright CRT, I think they're an excellent monitor; heads above the 2200/2400/2600 series.  That's why I wouldn't let them exchange mine for a newer one.
Tom


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on December 15, 2012, 01:23:11 PM
When our agency went digital, there was no use for the R2005D.  That's where the 2600 series shine.  There was even automated testing using the later models but they were too cheap to buy the software.

Yes, I'm not sure the 339 is the only problem, so any other bad chips get the socket treatment too.


Title: RE: R 2005D Motorola service monitor help
Post by: KA5IPF on December 15, 2012, 03:38:48 PM
"Never say, 'never'"...

<g>

Left off the "I" never use sockets! YMMV

Clif


Title: RE: R 2005D Motorola service monitor help
Post by: WB6DGN on December 15, 2012, 04:10:45 PM
Quote
That's where the 2600 series shine.

Yeah but in my case there was always a 2670 sitting around in the Mobile Shop if I really needed it.  Almost never did, though.  I hated that delay on the scope and spec. an. though.  Seemed 3 or 4 times longer than the HP I have at home and I'm not crazy about it.
Tom


Title: RE: R 2005D Motorola service monitor help
Post by: NJ1K on December 15, 2012, 05:06:35 PM
"Never say, 'never'"...

<g>

Left off the "I" never use sockets! YMMV

Clif

Huh??


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on December 18, 2012, 04:06:05 PM
Saga continues.  Got parts from Mouser, replaced ICs that I thought may be bad and nada.  Same thing, nothing changed.  I've got one more to replace, a 7405N hex inverter.

Funny thing is the 339 works on my breadboard, but not in the circuit.  But it may be the hex inverter dragging it down, that's my next try.

Anyone know where to get a cross reference on a DS75361N?  Dual TTL to MOS driver.  I doubt if it's bad, but wouldn't hurt to have a couple in case.


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on December 28, 2012, 01:53:34 PM
Looks like I've got it.  Apparently when I replaced a bad diode on the LVPS A5, I made a solder bridge across two others, so it was still in current lockout.  Trouble is the only way one can see it's in that lockout mode is on A4 U8 pin 13 or U2 pin 10.  If it's high, it's locking out the PWM.  In the meantime I pulled U8, the lockout IC and wiped out the AC switching FETs.  So I found the other short on the LVPS A5, replaced the FETs, the correct voltages came up on the A2 through A6 power supply boards, re-seated all the boards and it powered up, I have display, the buttons work and things appears normal.  I'm going to leave it on for a while before I button it up.

I really doubt if I could have fixed it without the schematics, unless I was really lucky.

Woo, Hoo.

Many thanks to NJ1K for his help.


Title: RE: R 2005D Motorola service monitor help
Post by: K7KBN on December 28, 2012, 03:44:11 PM
I think "hex inverters" are covered in the second year at Hogwarts ...  ;D


Title: RE: R 2005D Motorola service monitor help
Post by: N3DT on December 28, 2012, 06:03:34 PM
The hex inverters were working fine and still are.  Actually everything in the control board was doing exactly what it was supposed to do.  When I removed the overcurrent IC, that caused more problems.  There was just not enough explanation, at least for me, as to what is happening on the control board, in the Motorola manual.