Phase Linear 5100 Digital Tuner

joec999

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Sep 28, 2017
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#1
Hi Ed,

Thanks for the assist several months back on the D-500 up in Canada. While we were troubleshooting over the phone, I had the fella check around the relays and he spotted several bad connections at the quick-disconnects on the relays. He cleaned it up and told me it was back to normal operation.

Most recently, I received a few Phase Linear 5100 tuners and one of them is acting goofy. When I power it up on FM, the up scan button doesn't work but when I press the down scan button, it scans down a few a few tenths of a Mhz and stops as if it's trying to lock on a station. Then, if I repeat pressing the down scan button several more times, it will eventually drop down to something like 0.1 Mhz or some other unusual reading. I disconnected the ribbon cable to the front panel tact switches and checked to see if any of them had leakage and that they all had low contact resistance when depressed. They all look good.

I was wondering if you ever came across this issue before, or have any suggestions before I get into troubleshooting this unit.

Thanks,

Joe Cihlar
 

oldphaser

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Sep 8, 2012
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#2
Joe,

With regard to your issue with the up and down scan buttons, I don't recall ever running into this issue. The "manual" and "auto scan" tuning functions are described on page 15 in the 5100 service manual (see attached pdf).

NOTE: The attached pdf is missing scans of the over-sized "Schematic Diagram" and "P.C. Board Connection Diagram".

The Phase Linear 5100 is a re-badged Pioneer TX-D1000 at a time when Pioneer owned Phase Linear. It would be interesting to see if there is any additional information in a TX-D1000 service manual (which I do not have).

There is a "Schematic Diagram" for the Pioneer TX-D1000 available for free at https://www.hifiengine.com/manual_library/pioneer/tx-d1000.shtml
You will need to create an account to access the document, if you don't already have one.

The most common issue (which appears as a faulty power switch) is actually with the solder joint on the voltage regulator/transistor. This semiconductor can be located on a small vertical heat-sink located next to one of the largest electrolytic capacitors. Another issue I have been running into lately is with the PA1001-A I.C.


Ed
 

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oldphaser

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Sep 8, 2012
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#4
Is that the unobtanium IC Ed?
Lee,

The Pioneer PA1001 Ic does indeed look like its become un-obtanium.

It appears that US Pioneer no longer has them in stock. Price was around $45-$50 each. This IC was used in a bunch of other Pioneer products (tuners and receivers).
https://parts.pioneerelectronics.com/searchProducts.asp?searchString=PA-1001&page=1

I did find a Chinese site that claims to have them. My bet is more than likely what they have is a used part.

The other solution is to buy a basket case Pioneer product with one in them it and part it out.

I parted out a prototype Phase Linear 5100 (that was going to be remote controlled) a few years ago and gave all the IC's to Dean. Little did I know until later when I priced all the IC's out on Pioneer's web site how much they were all worth.

Ed
 

laatsch55

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#5
I think markthefixer came up with a workaround on it. Hopefully he'll chime in here..
 

joec999

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#6
Joe,

With regard to your issue with the up and down scan buttons, I don't recall ever running into this issue. The "manual" and "auto scan" tuning functions are described on page 15 in the 5100 service manual (see attached pdf).

NOTE: The attached pdf is missing scans of the over-sized "Schematic Diagram" and "P.C. Board Connection Diagram".

The Phase Linear 5100 is a re-badged Pioneer TX-D1000 at a time when Pioneer owned Phase Linear. It would be interesting to see if there is any additional information in a TX-D1000 service manual (which I do not have).

There is a "Schematic Diagram" for the Pioneer TX-D1000 available for free at https://www.hifiengine.com/manual_library/pioneer/tx-d1000.shtml
You will need to create an account to access the document, if you don't already have one.

The most common issue (which appears as a faulty power switch) is actually with the solder joint on the voltage regulator/transistor. This semiconductor can be located on a small vertical heat-sink located next to one of the largest electrolytic capacitors. Another issue I have been running into lately is with the PA1001-A I.C.


Ed
Ed,

Thank you for the quick reply. I will check on those things you have mentioned.

I do have another question about two other functional Phase 5100 tuners that came in for preventive maintenance and check over.

I noticed that when using the up/down scan buttons in FM, both units will scan and occasionally land on an even frequency (I.e. 101.4), then by giving the scan button one more press, it will go to the active station frequency, (in this case 101.5) un-mute and play. This happens about 30% of the time when scanning. Most times it will go to the correct active frequency and play.

As both tuners are acting the same, I am curious as to whether or not this is normal or could this be an FM alignment issue?

Thanks again,

Joe
 

joec999

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Sep 28, 2017
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#7
Joe,

With regard to your issue with the up and down scan buttons, I don't recall ever running into this issue. The "manual" and "auto scan" tuning functions are described on page 15 in the 5100 service manual (see attached pdf).

NOTE: The attached pdf is missing scans of the over-sized "Schematic Diagram" and "P.C. Board Connection Diagram".

The Phase Linear 5100 is a re-badged Pioneer TX-D1000 at a time when Pioneer owned Phase Linear. It would be interesting to see if there is any additional information in a TX-D1000 service manual (which I do not have).

There is a "Schematic Diagram" for the Pioneer TX-D1000 available for free at https://www.hifiengine.com/manual_library/pioneer/tx-d1000.shtml
You will need to create an account to access the document, if you don't already have one.

The most common issue (which appears as a faulty power switch) is actually with the solder joint on the voltage regulator/transistor. This semiconductor can be located on a small vertical heat-sink located next to one of the largest electrolytic capacitors. Another issue I have been running into lately is with the PA1001-A I.C.


Ed

Hi Ed,

Heating/cooling the TC9124AP would make it stable/unstable. I pulled the IC to swap it with one from another unit at which time I noticed a severed jumper near pin 1 of that same chip. The severed ends were barely touching each other. I replaced the jumper and swapped the IC (just for assurance) and will test the suspect IC in another 5100. So far, the unit with the bad jumper has been working fine. I'll update if anything changes.

I was curious if you spotted my previous question about the scan operation and whether tuner alignment may be necessary.

" I noticed that when using the up/down scan buttons in FM, both units will scan and occasionally land on an even frequency (I.e. 101.4), then by giving the scan button one more press, it will go to the active station frequency, (in this case 101.5) un-mute and play. This happens about 30% of the time when scanning. Most times it will go to the correct active frequency and play.

As both tuners are acting the same, I am curious as to whether or not this is normal or could this be an FM alignment issue?"


Thanks for your help!

Joe
 

joec999

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#8
I performed a full FM alignment. I found the existing adjustments to be reasonably close and only required some minor tweaking. The scan action is the same as before, so this may be normal operation. (only a minor annoyance if it is) If someone has information to the contrary, let me know.
 
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