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Power supply failure!
18 November 2019 | by  |
| Dusty but looks ok |
I was not able to see anything in the power supply with a visual check. Checking the schematic diagram I checked out the power on switch and it was good, next
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| Bad Varistor |
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| Shorted diode |
19 Responses to “Power supply failure!”
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That power supply is too puny for your IC-7610! You need a RS-35 for that, something that can make 20-25 amps nearly continuously. It’s not a surprise to me that the bridge failed. I use these things pretty hard in repeater service.
Those Astron linear supplies are easy to repair, as long as the transformer works. If you need to change a pass transistor, change them all. Good luck.
Good afternoon Jeff thanks for taking the time to comment, I have been running the rig at 50 watts but I am guessing using it for FT8 at that power or a bit more was to much. I have the proper Astron power supply on order now. I am checking the pass transistors today. So far it’s a varistor and bridge rectifier that are needed. If one is defective for sure both will be replaced.
Thanks for stopping by and have a good week.
73,
Mike
VE9KK
Are you talking about the CW CQ DX Contest? If so, it is Nov 23 and 24. https://www.cqww.com/
I meant to say CW CQ DX Contest….
Hi depending on the age of the supply it may be worth replacing the electrolytic caps while you are there.
Well the Rectifiers are the FIRST thing I would have checked.Just be glad you even have a radio to get on the air with!, I have not been on the air for several years,no radio, I am stuck with $714 a month SS and cant buy any radios. so I am dead in the water,I cant even listen anymore.
Have fun while it lasts.
73
N4ZDU
Hi. Varistors should always read open. Also, the transistors may have failed. If I am not mistaken, 2N5886’s work well in those supplies. It’s been a while since I repaired those supplies. If the transistors blow, they would usually short, giving the radio 20V or so. Most, but not all of these supplies have a crowbar circuit built in to blow the fuse if the output voltage gets too high.
I’d replace the bridge with a 50A, 100V or larger version. Digikey is a great place to get these from. Delivery is usually 2 days or less.
73, Clint, VE3CMQ
I would would also check the pass transistors…easy to remove. And, clean ALL the old dielectric grease off the transistors, insulator and the chassis and replace it with new. You should also check the tension on the pins…gently squeeze the socket pins, if necessary.
I also agree with the comment about the RS-20…it is designed to operate continuously at considerably less than 20 Amps, which is insufficient for your needs.
I have both an RS-20 & RS-35…the RS-20 is used only for an FM mobile transceiver base station. The RS-35 powers my K3.
These are very good power supplies…I like them much better than the switching type. Clean it up & it should last a long time.
73, Vic KB7GL
Good evening Carol thanks for stopping by and enlighting me to my retirement memory……:) I would guess if my radio had not shut down I would have eventually figured it out. Thanks for the reminder and my new supply should arrive before the contest and I should be good to go.
Thanks for stopping by Carol and have a good week.
73,
Mike
VE9KK
Top of the evening Howard the supply is not that old and I did check the cap’s and all seemed to be just fine. Thanks for your time and input have a good week Howard.
73,
Mike
VE9KK
Good evening Robert, yes I am very happy to have a rig and very very happy to have the rig I have. I am very fortunate and thankful that I am retired and have a pension from my place of employment. It does seem the rectifier is the only part that let go.
73,
Mike
VE9KK
Good evening Clint and nice to hear from an Ontarioian, I feel like such a dope and I just don’t know what I was thinking regarding the varistor in this post. Thanks for being very kind regarding my poor oversight of the varistor. This afternoon I did check the pass transistors (there are 2 of them in this supply) and they were just fine. The power supply does have crowbar protection as well. This supply is to small for the 7610 and I have on order from Radio World in Toronto the proper Astron supply and it should be here this week sometime.
Have a great week Clint
73,
Mike
VE9KK
Good evening Vic thanks for taking the time to comment, this evening I checked the pass transistors and they passed with flying colors. It seems the bridge rectifier is the only part that has to be replaced. I do have another Astron power supply on order and it is the proper size for the 7610 to operate at full power. As for the dielectric grease, I am also ordering it and replacing it on the pass transistors as well on the new bridge rectifier.
Have a great week Vic,
73
Mike
VE9KK
This is a comment for Robert, N4ZDU. Robert, your e-mail addresses listed on QRZ.COM are not working. I thought I’d let you know that there is a web site that allows licensed hams to operate other participating hams’ and ham clubs’ stations remotely. You register on their site, download their software and upload a copy of your license to their site and then you ask permission of a station’s control operator to transmit. Even without permission, you can usually listen. If you don’t have a computer, you can even do it from an android smartphone. There are dozens upon dozens of remote stations on line at any given time.
Here’s the link to the RemoteHams site.
https://www.remotehams.com/
I just stumbled upon this YouTube video of a ham in England using RemoteHams to make an over-the-air QSO with a ham in Spokane who coincidentally was not far from where the particular remote station is located that the ham in the UK is using.
https://www.youtube.com/watch?v=xefrKQbK6rQ
And, here’s a brief YouTube tutorial that popped up:
https://www.youtube.com/watch?v=W1wlmawAP5k
I hope this helps you get back on the air, even without a rig. Good luck to you! And, good luck to VE9KK with his amplifier troubleshooting!
73
Rich
WB3EGD
If a power supply unit has a marginal capacity for the job in hand ,add a 60 to 100Ah battery ,via a 40A diode and between battery and transceiver a fuse
Then you also will be able to keep operating (for some time) in the event of a power cut
If the voltage drop over the added 40A diode is too high you can compensate by increasing the PSU output voltage (through a usual trimpot)
An old car battery which no longer start the car smoothly will highly likely be adequate for the above task .
Frank , EI7KS in County Wicklow -Ireland
Rich thanks very much for posting the info and I hope that Robert sees this.
73,
Mike
VE9KK
Good evening Frank, thanks for reading the blog and taking the time to leave a comment. Excellent idea and it makes sense to have a setup that when the power is out you can still keep operating.
73,
Mike
VE9KK
One other note. I’ve had a 7610 for three years and it would sometimes shutdown when I tried to run it at full power. I thought it was RF in the shack. It wasn’t.
It turns out that the 7610 and the 7300 are finicky about input power voltage, which I only just found out by doing some online research. The problem appears to be solved in my case by giving it it’s own dedicated power supply, and only use the manufacturers hefty cable wired directly to it, not through RigRunners or anything else that might cause a voltage drop.
Good evening Gary and thanks for stopping by, yes I have my 7610 on a dedicated power supply. I have not had mine shut down yet but I too have heard the same regarding the power supply voltage.
73 and Happy Holidays,
Mike
VE9KK