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Hewlett Packard 5335A Universal Frequency Counter Fail Massage 5.1
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Hello Everyone I have a Hewlett Packard 5335A Universal Frequency Counter With Fail Massage 5.1 when Powered on, according to the manual it is Start Interpolator Problem, I have tried to trace the problem but no luck I hope that some one has some experience with this counter and can Point me in the right direction Thank You I am looking forward to hear from a knowledgeable individual that is more knowledgeable I Thank You Sal C. Cornacchia RF Microwave Engineer (Ret.) |
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Read this thread over on EEVblog start to finish: Pay particular attention to comments about the power supplies and relay/relay socket. Then check the power supplies. 5335As will act really goofy if the relay socket is about to fail so you have to make sure it's OK before you do any other troubleshooting. Orin. On Fri, Sep 11, 2020 at 11:31 AM CORNACCHIA via <corcsal=[email protected]> wrote:
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Hello Orin, Thank You for the Blog I wil read it and Pay Attention what You have mentioned I appreciate for taking the time to help me out.?
On Friday, September 11, 2020, 06:14:09 p.m. EDT, Orin Eman <orin.eman@...> wrote:
Read this thread over on EEVblog start to finish: Pay particular attention to comments about the power supplies and relay/relay socket. Then check the power supplies. 5335As will act really goofy if the relay socket is about to fail so you have to make sure it's OK before you do any other troubleshooting. Orin. On Fri, Sep 11, 2020 at 11:31 AM CORNACCHIA via <corcsal=[email protected]> wrote:
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Sal, ? I have a 5335A that has been sitting on the shelf that has been awaiting attention for some time.? It was once fully functional but developed a couple of error messages unexpectedly.? And, as I indicated, I still have to open it up and look around to see what is happening. ? When first powered up there is a fail message 4.6 (MRC COUNTING PROBLEM IN REG-E OR T).? If any button is pressed the fail messages changes to 5.1 (START INTERPOLATOR PROBLEM) and the display and other indicators begin to flash erratically. ? Perusing the schematics I get the impression that there is possibly a clocking problem around the Multiple Register Counter (MRC) U6 that also fees the Interpolator counters via the start-stop control circuitry.? All of these items use the 10 MHz clocking. ? If you have the manual (mine is P/N 05335-90021 3rd edition March 1983) I recommend starting at the troubleshooting flowchart on page 8-57.? It will lead you to the proper following pages describing the troubleshooting techniques plus voltages & waveforms.? A good overview of the whole unit is shown in the block diagrams on pages 8-97 (for options 010, 020 & 030) or page 8-99 (if your unit includes option 040). The circuitry that I referenced earlier is located in the upper right corner of these block diagrams in the ¡°A4 MAIN LOGIC¡± block. ? Sorry that I cannot assist any further since I have not had the time to really investigate the failures this unit is showing but I hope that what I have written will serve as some rudimentary guidance should you have to dig deeper into locating your problem. ? Regards, ? Greg |
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Hi Greg, I have tried everything following the service manual carefully all voltages appear to be in order as well as waveforms according to manual everything is working except for fail message 5.1 when first powered on, the start interpolator wave forms seem to be OK I just don't know what else I can do. Thank You so much for all the help. Sal C. Cornacchia
On Saturday, September 12, 2020, 02:41:19 p.m. EDT, Greg Muir via groups.io <big_sky_explorer@...> wrote:
Sal, ? I have a 5335A that has been sitting on the shelf that has been awaiting attention for some time.? It was once fully functional but developed a couple of error messages unexpectedly.? And, as I indicated, I still have to open it up and look around to see what is happening. ? When first powered up there is a fail message 4.6 (MRC COUNTING PROBLEM IN REG-E OR T).? If any button is pressed the fail messages changes to 5.1 (START INTERPOLATOR PROBLEM) and the display and other indicators begin to flash erratically. ? Perusing the schematics I get the impression that there is possibly a clocking problem around the Multiple Register Counter (MRC) U6 that also fees the Interpolator counters via the start-stop control circuitry.? All of these items use the 10 MHz clocking. ? If you have the manual (mine is P/N 05335-90021 3rd edition March 1983) I recommend starting at the troubleshooting flowchart on page 8-57.? It will lead you to the proper following pages describing the troubleshooting techniques plus voltages & waveforms.? A good overview of the whole unit is shown in the block diagrams on pages 8-97 (for options 010, 020 & 030) or page 8-99 (if your unit includes option 040). The circuitry that I referenced earlier is located in the upper right corner of these block diagrams in the ¡°A4 MAIN LOGIC¡± block. ? Sorry that I cannot assist any further since I have not had the time to really investigate the failures this unit is showing but I hope that what I have written will serve as some rudimentary guidance should you have to dig deeper into locating your problem. ? Regards, ? Greg |
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Hi Orin, Thank You for the info I will look it over very carefully all voltages appear to be in order I have taken the relay out of the socket and checked and cleaned it seems OK but I will keep working at it. Sal C. Cornacchia
On Saturday, September 12, 2020, 02:41:19 p.m. EDT, Greg Muir via groups.io <big_sky_explorer@...> wrote:
Sal, ? I have a 5335A that has been sitting on the shelf that has been awaiting attention for some time.? It was once fully functional but developed a couple of error messages unexpectedly.? And, as I indicated, I still have to open it up and look around to see what is happening. ? When first powered up there is a fail message 4.6 (MRC COUNTING PROBLEM IN REG-E OR T).? If any button is pressed the fail messages changes to 5.1 (START INTERPOLATOR PROBLEM) and the display and other indicators begin to flash erratically. ? Perusing the schematics I get the impression that there is possibly a clocking problem around the Multiple Register Counter (MRC) U6 that also fees the Interpolator counters via the start-stop control circuitry.? All of these items use the 10 MHz clocking. ? If you have the manual (mine is P/N 05335-90021 3rd edition March 1983) I recommend starting at the troubleshooting flowchart on page 8-57.? It will lead you to the proper following pages describing the troubleshooting techniques plus voltages & waveforms.? A good overview of the whole unit is shown in the block diagrams on pages 8-97 (for options 010, 020 & 030) or page 8-99 (if your unit includes option 040). The circuitry that I referenced earlier is located in the upper right corner of these block diagrams in the ¡°A4 MAIN LOGIC¡± block. ? Sorry that I cannot assist any further since I have not had the time to really investigate the failures this unit is showing but I hope that what I have written will serve as some rudimentary guidance should you have to dig deeper into locating your problem. ? Regards, ? Greg |
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Hi Sal
I also had a 5.1 error on my 5335A. I measured all voltages etc on the power supply and everything looked fine, but I still got the 5.1 error. I had to search for the problem for quite a while and was unable to locate it; but luckily, I got access to a thermal camera and with the aid of this, I found a shorted tantalum capacitor on the input board mounted at the front panel. I don't remember exactly which board it was, but right behind the front panel, there are these input boards where the special Schmitt trigger ASIC is. Check all the blue tantalum "pill style" capacitors on these boards. Maybe you have a similar issue like I had. BR Tobias HB9FSX |
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Thank You Orin any help is very much appreciated as I am getting old nearly 80 and my mind is not serving me very well. Again thank You for taking the time if You come up with any suggestions it will be very much appreciated.?
On Saturday, September 12, 2020, 03:14:20 p.m. EDT, CORNACCHIA via groups.io <corcsal@...> wrote:
Hi Orin, Thank You for the info I will look it over very carefully all voltages appear to be in order I have taken the relay out of the socket and checked and cleaned it seems OK but I will keep working at it. Sal C. Cornacchia
On Saturday, September 12, 2020, 02:41:19 p.m. EDT, Greg Muir via groups.io <big_sky_explorer@...> wrote:
Sal, ? I have a 5335A that has been sitting on the shelf that has been awaiting attention for some time.? It was once fully functional but developed a couple of error messages unexpectedly.? And, as I indicated, I still have to open it up and look around to see what is happening. ? When first powered up there is a fail message 4.6 (MRC COUNTING PROBLEM IN REG-E OR T).? If any button is pressed the fail messages changes to 5.1 (START INTERPOLATOR PROBLEM) and the display and other indicators begin to flash erratically. ? Perusing the schematics I get the impression that there is possibly a clocking problem around the Multiple Register Counter (MRC) U6 that also fees the Interpolator counters via the start-stop control circuitry.? All of these items use the 10 MHz clocking. ? If you have the manual (mine is P/N 05335-90021 3rd edition March 1983) I recommend starting at the troubleshooting flowchart on page 8-57.? It will lead you to the proper following pages describing the troubleshooting techniques plus voltages & waveforms.? A good overview of the whole unit is shown in the block diagrams on pages 8-97 (for options 010, 020 & 030) or page 8-99 (if your unit includes option 040). The circuitry that I referenced earlier is located in the upper right corner of these block diagrams in the ¡°A4 MAIN LOGIC¡± block. ? Sorry that I cannot assist any further since I have not had the time to really investigate the failures this unit is showing but I hope that what I have written will serve as some rudimentary guidance should you have to dig deeper into locating your problem. ? Regards, ? Greg |
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Thank You?Tobias I will take the front panel apart and will do what You have?suggested. Sal
On Saturday, September 12, 2020, 03:31:06 p.m. EDT, Tobias Pluess <tobias.pluess@...> wrote:
Hi Sal I also had a 5.1 error on my 5335A. I measured all voltages etc on the power supply and everything looked fine, but I still got the 5.1 error. I had to search for the problem for quite a while and was unable to locate it; but luckily, I got access to a thermal camera and with the aid of this, I found a shorted tantalum capacitor on the input board mounted at the front panel. I don't remember exactly which board it was, but right behind the front panel, there are these input boards where the special Schmitt trigger ASIC is. Check all the blue tantalum "pill style" capacitors on these boards. Maybe you have a similar issue like I had. BR Tobias HB9FSX |
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Hi again Sal, ? I hear you.? This old age thing doesn¡¯t help a bit.? I¡¯m 71. ? Tobias gave a good reminder about the capacitors.? These little 196D tantalums are notorious for failures.? When on a supply line you can sometimes find them by seeing a little drop of tantalum oozing out of a crack on them mostly near the top.? But that isn¡¯t always the case.? It takes an effort to find the bad ones. ? I suspect that the issue with my unit is probably a capacitor as well given the unexpected failure after being on standby power for several years.? The normal sequence in any failure situation with this older equipment is (1) check power supply voltages and ripple then (2) start thinking about capacitor issues.? I have witnessed problems where capacitors will seem to be functioning in the circuit but have had their ESR start to get higher causing things to misbehave. ? The manual on this unit can be a bit daunting at first look but HP did a very good job of producing a document that really helps locate problems.? But with any document of this sort there will always be failure modes that were not thought about.? It¡¯s a shame that the company didn¡¯t keep producing things like this as they morphed through the years.? But it is understood that more money can be made by the manufacturer if they keep their circuitry secret and force the user to send it in for repair (if it can be repaired!).? And higher scale circuit integration using custom ASICs doesn¡¯t help much either. ? I¡¯ll be watching the list to see what you find. ? Regards, ? Greg |